• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4879
  • 2024
  • 688
  • 614
  • 421
  • 254
  • 170
  • 90
  • 80
  • 76
  • 45
  • 39
  • 36
  • 36
  • 36
  • Tagged with
  • 11340
  • 1674
  • 1310
  • 969
  • 875
  • 855
  • 782
  • 760
  • 709
  • 656
  • 612
  • 572
  • 558
  • 527
  • 515
  • 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.
1

Charged particle dynamics in sheared magnetic reversals with application to the earth's magnetotail

Tsalas, Maximos Georgios January 2000 (has links)
No description available.
2

Spectral analysis of field emission flicker (1/f) noise

Gesley, Mark Alan 06 1900 (has links) (PDF)
Ph.D. / Applied Physics / Spectral analysis of field emission noise induced by emitter surface equilibrium density fluctuations is developed. The noise spectrum factors as S (ω) = S (ω) + SB (ω) for a canonical ensemble, which characterizes adsorbate covered emitters. S∞ (ω) and SB (ω) correspond to unbounded diffusion and the boundary effect respectively. Chemical diffusivity D [subscript c] is defined by Fick's first law. Its equilibrium limit, termed hydrodynamic D [subscript h], is derived from S (ω) and related to the adsorbate fluctuations. These diffusivities are compared using irreversible thermodynamic and Kubo relations. Their equality is ensured by evaluation of the excess entropy production only when the density gradient is small and no phase change occurs. Two dimensional adsorbate phase transitions are identified by correlating incipient nonlinearity in the Arrhenius plot of diffusivity with the onset of a temperature dependent total noise power, which is proportional to adsorbate isothermal compressibility. Examples using K/W, Xe/W, and H/W are given. Thermal field emission noise is characterized by a grand canonical ensemble (GCE). Here the diffusive fluctuation mechanism includes adatom creation and defect vacancy formation resulting from surface free energy minimization. Adatom dynamics are governed by a stochastic diffusion equation. A multidimensional version of Carson's theorem is formulated, which leads to S(ω) ≈ C( x =0, ω) N[subscript c][superscript -1](ω), where (hkl) geometry affects C( x =0, ω) and N[subscript c](ω) accounts for probe spatial averaging. From this factorization of S (ω) an outstanding noise power divergence problem for diffusive equilibrium fluctuations within a GCE is solved. The solution requires finite fluctuation lifetime, which is also proved to be a necessary equilibrium condition. The other part of the solution leads to a new method of measuring the resolution of the microscope. Derived values agree well with a calculation that considers the transverse momentum distribution of the field emitted electrons. The S (ω) characteristics of tungsten thermal field emission from W (112), W (310), and W (100) planes are explained in detail. Diffusivity values, their corresponding activation energies, and the defect vacancy formation activation energy agree well with other experimental data. Conditions for the broadest band S (ω) [proportional] ω [superscript -1] are given and a hypothesis is proposed explaining its frequent occurrence for diffusive equilibrium systems.
3

The physical demands of elite men's field hockey and the effects of differing substitution methods on the physical and technical outputs of strikers during match play a thesis submitted to the Auckland University of Technology in fulfilment of the degree of Masters of Health Science, AUT University, February 2008 /

Lythe, John January 2008 (has links)
Thesis (MHSc--Health Science) -- AUT University, 2008. / Includes bibliographical references. Also held in print (160 leaves ; 30 cm.) in the Archive at the City Campus (T 612.044 LYT)
4

A cinematographic analysis and comparison of the "throw" to three established field hockey strokes

Visser, Mary Frances January 1976 (has links)
The purpose of this study was to analyze the throw technique as it related to the technique of the three established field hockey strokes. From this analysis, a description of the throw technique was formulated and compared to that of the push, flick, and scoop strokes. The subject was a female field hockey player who had been a member of the United States Field Hockey Team.The comparison of the four strokes was made from a film analysis of two performances of each, one from the frontal and one from the saggital plane. Ten frames of each performance were selected for analysis. Each sequence was analyzed by the Ball State Computer program "Filmdat." Additional measurements were taken from the film itself to complete the study.From the analysis of data, it was concluded that no consistant pattern of differences in body segment patterns of motion, the angular velocity of each segment could be determined for any of the four strokes. The pattern of percent contribution of the extremities and trunk to total body kinetic energy was similar in all four strokes considered in the study. It was also concluded that the stick velocity, the stick angle at release, the height of the ball at release, and the height of the ball during flight distinguished the push and scoop strokes from the flick and throw strokes. The above data could not distinguish the flick stroke from the throw stroke. The path of the body center of gravity was able to distinguish the scoop stroke from the push, flick, and throw strokes, but could not separate the push from the flick or throw strokes.
5

Nathan Field the actor-playwright,

Brinkley, Roberta Florence. January 1928 (has links)
Thesis (Ph. D.)--Yale University, 1924.
6

Nathan Field the actor-playwright,

Brinkley, Roberta Florence. January 1928 (has links)
Thesis (Ph. D.)--Yale University, 1924.
7

The field hockey pass a cinematographic analysis.

Cohen, Judith Suzann, January 1969 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
8

John Field, sein Leben und seine Werke ...

Dessauer, Heinrich, January 1912 (has links)
Inaugural-Dissertation zur Erlangung der philosophischen Doktorwürde der Hohen philosophischen Fakultät der Universität Leipzig. / Lebenslauf. "Die wichtigsten Quellen": p. (vii)-viii.
9

Field emission from high resistance semiconductors

Vaslow, Dale Franklin, January 1969 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
10

Spectral analysis of field emission flicker (1/f) noise /

Gesley, Mark Alan. January 1985 (has links)
Thesis (Ph. D.)--Oregon Graduate Center, 1985.

Page generated in 0.0424 seconds