• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 552
  • 142
  • 61
  • 43
  • 24
  • 12
  • 5
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 1241
  • 1241
  • 314
  • 304
  • 200
  • 193
  • 184
  • 156
  • 143
  • 132
  • 117
  • 112
  • 109
  • 100
  • 98
  • 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.
391

Mechanochemically synthesized nanomaterials for intermediate temperature solid oxide fuel cell membranes

Hos, James Pieter January 2005 (has links)
[Truncated abstract] In this dissertation an investigation into the utility of mechanochemically synthesized nanopowders for intermediate temperature solid oxide fuel cell components is reported. The results are presented in the following parts: the synthesis and characterisation of precursors for ceramic and cermet components for the fuel cell; the physical and electrical characterisation of the electrolyte and electrodes; and the fabrication, operation and analysis of the resulting fuel cells. Samarium-doped (20 mol%) ceria (SDC) nanopowder was fabricated by the solid-state mechanochemical reaction between SmCl3 with NaOH and Ce(OH)4 in 85 vol% dilution with NaCl. A milling time of 4 hours and heat treatment for 2 hours at 700°C yielded a material with equivalent particle and crystallite sizes of 17 nm. The existence of a complete solid solution was affirmed by electron energy loss spectroscopy and x-ray diffraction analysis. Doped-ceria compacts were sintered for 4 hours at 1350°C forming ceramics of 88% theoretical density. The ionic conductivity in flowing air was 0.009 S/cm, superior to commercially supplied nanoscale SDC. Anode precursor composite NiO-SDC nanopowder was synthesized by milling Ni(OH)2 with the previously defined SDC formulation ... Anode-supported fuel cells were fabricated on a substrate of at least 500 'm 55wt%NiO-SDC with 17vol% graphite pore formers. Suspensions of SDC were deposited by aerosol on the sintered bilayer at a thickness around 5 'm. A cathode of 10% SDC (SmSr)0.5CoO3 was deposited onto the sintered electrolyte and after firing had a thickness of around 25 'm. Operation of fuel cells in single-chamber mixtures of CH4 and air diluted in argon were successful and gave power outputs of 483 'W/cm2. Operation in undiluted 25 vol% CH4:air gave a power output of 5.5 mW/cm2. It was shown that a large polarisation resistance of 4.1 Ω.cm2 existed and this was assigned to losses in the anode, namely mass transport limitation associated with the catalytic combustion of methane and insufficient porosity. The large surface area of Ni appeared to allow more methane to combust and hence prevented its electrochemical reaction from occurring, thus limiting the performance of the cell. The synthesis procedures, ceramic processing and fabrication techniques and testing methods are discussed and contribute significant understanding to the fields of ceramic science and fuel cell technology.
392

Transient studies of Ni-, Cu-based electrocatalysts in CH₄ solid oxide fuel cell

Yu, Zhiqiang. January 2007 (has links)
Dissertation (Ph. D.)--University of Akron, Dept. of Chemical Engineering, 2007. / "December, 2007." Title from electronic dissertation title page (viewed 03/12/2008) Advisor, Steven S. C. Chuang; Committee members, Lu-Kwang Ju, Edward Evans, W. B. Arbuckle, Stephen Z. D. Cheng; Department Chair, Lu-Kwang Ju; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
393

Multivariable robust control of a simulated hybrid solid oxide fuel cell gas turbine plant

Tsai, Alex, January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xiv, 273 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 184-189).
394

High temperature magnetic properties of transition metal oxides with perovskite structure /

Baskar, Dinesh, January 2008 (has links)
Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 111-119).
395

Design and analysis of a hybrid guideway heating system for Morgantown personal rapid transit

Vedam, Anand. January 2009 (has links)
Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains x, 85 p. : ill. (some col.), map. Includes abstract. Includes bibliographical references (p. 71-73).
396

Metal and alloy nanoparticles synthesis, properties and applications /

Njoki, Peter Njunge. January 2007 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Department of Chemistry, 2007. / Includes bibliographical references.
397

The Ba-Pb-O system and its potential as a solid oxide fuel cell (SOFC) cathode material /

Sharp, Matthew David. January 2007 (has links)
Thesis (M.Phil.) - University of St Andrews, September 2007.
398

Composite proton exchange membranes for fuel cells

Liu, Ping. January 2006 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Chemistry, 2006. / Title from PDF t.p. (viewed on June 19, 2009) Includes bibliographical references (p. 148-154). Also issued in print.
399

Bioconversion of cellulose into electrical energy in microbial fuel cells

Rismani-Yazdi, Hamid. January 2008 (has links)
Thesis (Ph. D.)--Ohio State University, 2008.
400

Characterization of mass transport processes to enable PEM fuel cell start-up from low temperatures /

Harris, Daniel I. January 2009 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 68-71).

Page generated in 0.0831 seconds