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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

A kinetic study of the electron stimulated adsorption of ammonia on tungsten single crystal surfaces /

Kong, Fu wing. Dawson, P.T. January 1900 (has links)
Thesis (Ph.D.)--McMaster University, 2004. / Includes bibliographical references (leaves193-201). Also available via World Wide Web.
252

Tungsten carbides as anode electrocatalyst of direct methanol fuel cell

Ren, Qiao. January 2007 (has links)
Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisors: Jingguang G. Chen, Dept. of Chemical Engineering; and Thomas P. Beebe, Jr., Dept. of Chemistry & Biochemistry. Includes bibliographical references.
253

Dynamic mechanical behavior and high pressure phase stability of a zirconium-based bulk metallic glass and its composite with tungsten

Martin, Morgana. January 2008 (has links)
Thesis (Ph. D.)--Materials Science and Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Thadhani, Naresh; Committee Member: Doyoyo, Mulalo; Committee Member: Kecskes, Laszlo; Committee Member: Li, Mo; Committee Member: Sanders, Thomas; Committee Member: Zhou, Min.
254

Effects of molybdenum, vanadium, tungsten and cobalt on growth of rhizobia and their hosts

Jha, Kali Kant, January 1963 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 143-153).
255

The genesis of the Grey River tungsten prospect : a fluid inclusion, geochemical, and isotopic study /

Higgins, Neville Charles, January 1980 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland. / Bibliography : leaves 405-441, 538-539. Also available online.
256

Investigation of vaporization and condensation mechanisms in electrothermal vaporizers.

Hughes, Dianne M. January 1900 (has links)
Thesis (Ph. D.)--Carleton University, 1996. / Also available in electronic format on the Internet.
257

The electrodeposition of cobalt-tungsten and nickel-cobalt-tungsten alloys from acid plating baths

Hoglund, Paul Franklin, January 1945 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1945. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 161-162.
258

Homogeneity of metal matrix composites deposited by plasma transferred arc welding

Wolfe, Tonya Brett Bunton. January 2010 (has links)
Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on July 8, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Materials Engineering, Department of Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.
259

Non-ductile design of demo divertor armour : towards the probabilistic reliability assessment of brittle tungsten components in their irradiated state

Lessmann, Moritz January 2016 (has links)
In-vessel tungsten components of a future demonstration fusion reactor are likely to be operated in the material's non-ductile regime. Assessment of the components' reliability is not possible with current ductile design codes or through experimental qualification. There is therefore an urgent need for non-ductile assessment procedures. One such approach currently considered is Weibull's weakest link theory, which is based on linear-elastic fracture mechanics and has its origins in ceramics. A full assessment of its validity has been performed, and the challenge of obtaining irradiated material data addressed. Bend tests at the macroscopic scale confirm previous findings that the scatter in strength of pure tungsten follows a two-parameter Weibull distribution, provided the material fractures within its elastic regime. However, tests conducted over a range of specimen sizes reveal the technique's shortcomings in accurately predicting the material's size effect in fracture, questioning its applicability to pure tungsten and also other brittle metallic materials. Fracture strength tests conducted at the micrometre scale through cantilever bending have addressed the challenge of obtaining irradiated material data. An ultra-fine grained self-passivating tungsten alloy, considered as an alternative contender to tungsten for in-vessel components, is shown to fracture within its linear-elastic regime at the microscopic scale. A reliable and repeatable measurement of its strength of approximately 5.9 GPa is obtained. The scatter in measurements is shown to be greater than random errors, and to be described well by a two-parameter Weibull distribution. Cantilever tests conducted over a range of specimen sizes reveal a strong size effect (4.3 - 9.0 GPa), which is accurately predicted by Weibull's weakest link theory. Ion implantations, conducted in the tungsten alloy to mimic neutron induced elastic collision damage, result in a statistically confirmed drop (6 %) in cantilever measured fracture strength at low doses (0.7 dpa), and an increase (9-16 %) at higher doses (7 dpa).The cantilever test technique is therefore suitable for the measurement of ion and neutron irradiation effects on the material's fracture strength. Provided a full validation of Weibull's weakest link theory strength extrapolation from the micro- to macroscopic scale is realised on a future heterogeneity free material batch, irradiated material data obtained from cantilever tests could be used to assess the reliability of in-vessel components fabricated from a self-passivating tungsten alloy, and fill the current gap in non-ductile design assessment procedures.
260

Anionic polyhydride compounds of the transition metals

Berry, Adam January 1987 (has links)
No description available.

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