MgH2 is considered to be one of the most promising options for a solid state hydrogen storage material. For practical use it is still imperative to find a convenient means of overcoming its slow kinetics and high stability. In this investigation, a range of binary and ternary metal oxides of aluminium, silicon, titanium, and zirconium, as well as Pd-modified Ti02 samples, were prepared and characterised. The prepared oxides were ball milled with MgH2, and the hydrogen sorption behaviour of the ball milled mixtures was investigated using DSC-TGA-MSS, Sieverts and IGA. Thermodynamic parameters including enthalpies and entropies of hydrogen desorption were determined from experimental data, and activation energy calculations along with modelling of the kinetics were used to understand the mechanism and rate-limiting step of dehydrogenation. Oxide components, calcination temperature, and surface area were found to have a significant impact on the hydrogen sorption behaviour of MgH2 in the ball milled mixtures. Of the prepared binary and ternary oxides, Ti02 and mixed oxides with a Ti02 component were found to lower the dehydrogenation onset temperature by as much as 100°C, while additions of Pd-modified Ti02 resulted in the lowest dehydrogenation onset temperature of 205°C, compared to 360°C for ball milled MgH2. In addition, rates of hydrogen desorption and absorption were significantly increased as a result of the Ti02 and Ti02 - Pd additives. Dehydrogenation of 90 % of the full H2 capacity took 6 min at 300°C, compared to 230 min for milled MgH2 at 350°C. It was found that a reduction of the Ti02 oxide resulted in the active species responsible for the enhanced dehydrogenation behaviour. Through analysis of the reaction kinetics, the mechanism of dehydrogenation was found to change from a surface controlled, contracting volume model for ball milled MgH2 to one of a Johnson-Mehl-Avrami model of two - dimensional nucleation and growth upon addition of Ti02 and Ti02 - Pd.

Integrated high-temperature (HT) ultrasonic sensors have been developed successfully by using piezoelectric bismuth titanate and lead zirconate titanate films HT ultrasonic transducers for real-time, non-destructive, and non-intrusive diagnosis of polymer injection molding (IM) processes. The HT ultrasonic sensors can be integrated onto the barrel and/or mold of IM machine, according to the customer's requirements. These sensors can be operated up to 400°C without cooling system and ultrasonic couplant, and can be miniaturized with sufficient signal strength and signal-to-noise ratio. / The chosen IM processes are grouped to large- and small-scale 1M processes. The large-scale ones include conventional IM, co-injection molding (COIM), and fluid (gas/water) assisted injection molding (GAIM/WAIM). A filling incompleteness of 1 volume-% for IM of polycarbonate (PC) part, the core (PC) material movement and layers dimensions for COIM, the fluid motion, thickness and deformation of the hollowed high-density polyethylene (HDPE) part for GAIM/WAIM were diagnosed during processing by ultrasonic sensors and techniques developed. / The small-scale ones include IM for microfluidic device (IMMF) and micromolding (MM). The optimization of holding pressure for producing a flat polymethyl methacrylate (PMMA) part (surface roughness < 5 mum) having micro structures for IMMF, estimation of temperature of polyacetal copolymer (POM) melt in the barrel and filler concentration of nylon 66 (PA66) mixed with polyhedral oligomeric silsesquioxanes (POSS) part in the mold for MM, and evaluation of thickness variation of molded alumina ceramic powder part for MM were demonstrated. The melting stages and quality of low-density polyethylene (LDPE) in the barrel has been successfully monitored using ultrasound. The important phenomena during melting processes, such as partially melting pellets, air bubbles, melting completeness, and effects of melting temperature and rotation speed have been diagnosed by ultrasonic signatures. / These diagnostic results verify that the developed integrated HT ultrasonic sensors and techniques are capable of monitoring various IM processes to fabricate parts and products having complex formation, tiny size and micro structures, and evaluating the part quality in order to provide timely information for process optimization.

Thesis (M.Eng.). / Written for the Dept. of Mechanical Engineering. Title from title page of PDF (viewed 2008/01/14). Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1968.

Thesis (M.S.)--University of Michigan, 1968.

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 211-213).

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 60-61). Also available on the World Wide Web.

Thesis (Ph. D.)--Florida State University, 2006. / Advisors: Chuck Zhang, Ben Wang, Florida State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering. Title and description from dissertation home page (viewed Sept. 18, 2006). Document formatted into pages; contains xiii, 168 pages. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 188-192). Available also in a digital version from Dissertation Abstracts.

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