• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 894
  • 78
  • 50
  • 38
  • 37
  • 16
  • 8
  • 7
  • 4
  • 4
  • 3
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 1242
  • 566
  • 566
  • 566
  • 550
  • 549
  • 439
  • 383
  • 360
  • 338
  • 321
  • 316
  • 315
  • 307
  • 297
  • 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

Calibration and data reduction algorithms for non-conventional multi-hole pressure probes

Ramakrishnan, Vijay 30 September 2004 (has links)
This thesis presents the development of calibration and data-reduction algorithms for non-conventional multi-hole pressure probes. The algorithms that have been developed for conventional 5- and 7-hole probes are not optimal for probes with port arrangements (on the probe tip) that are non-conventional. Conventional algorithms utilize the axisymmetry of the port distribution pattern to define the non-dimensional pressure coefficients. These coefficients are typically defined specifically for these patterns, but fail to correctly represent different patterns of port arrangements, such as patterns without axisymmetry or regularity. The algorithms introduced herein can handle any pattern of port arrangement, from axisymmetric and regular to random. Moreover, they eliminate the need to separate the measurement domain of a probe to "low-angle" and "high-angle" regimes, typical in conventional 5- and 7-hole-probe algorithms that require two different sets of pressure coefficient definitions and procedures. Additionally, the algorithms have been formulated such that they facilitate redundancy implementations, especially in applications where such redundancy is important, such as air-data systems. The developed algorithms are first applied to a non-conventional probe, a nearly omni-directional 18-hole probe, and demonstrate very high flow measurement accuracy. Subsequently, the algorithms were applied to a new 12-hole, nearly omni-directional, flow velocity measurement probe capable of measuring reversed flows. The new 12-hole design offers several advantages over a previously developed, 18-hole, nearly omni-directional probe. The probe is optimized in the sense that, regardless of the flow direction, it allows calculation of the 4 unknown flow quantities, i.e. the two flow angles, the velocity magnitude and the static pressure, with the minimum necessary number of holes/ports on the probe tip. This probe also has a non-conventional arrangement of its pressure ports and therefore the new calibration and data-reduction algorithms can be effectively employed. With theoretically generated pressure data for the 12-hole probe, the coefficient definitions are analyzed and found to be well-behaved.
2

Calibration and data reduction algorithms for non-conventional multi-hole pressure probes

Ramakrishnan, Vijay 30 September 2004 (has links)
This thesis presents the development of calibration and data-reduction algorithms for non-conventional multi-hole pressure probes. The algorithms that have been developed for conventional 5- and 7-hole probes are not optimal for probes with port arrangements (on the probe tip) that are non-conventional. Conventional algorithms utilize the axisymmetry of the port distribution pattern to define the non-dimensional pressure coefficients. These coefficients are typically defined specifically for these patterns, but fail to correctly represent different patterns of port arrangements, such as patterns without axisymmetry or regularity. The algorithms introduced herein can handle any pattern of port arrangement, from axisymmetric and regular to random. Moreover, they eliminate the need to separate the measurement domain of a probe to "low-angle" and "high-angle" regimes, typical in conventional 5- and 7-hole-probe algorithms that require two different sets of pressure coefficient definitions and procedures. Additionally, the algorithms have been formulated such that they facilitate redundancy implementations, especially in applications where such redundancy is important, such as air-data systems. The developed algorithms are first applied to a non-conventional probe, a nearly omni-directional 18-hole probe, and demonstrate very high flow measurement accuracy. Subsequently, the algorithms were applied to a new 12-hole, nearly omni-directional, flow velocity measurement probe capable of measuring reversed flows. The new 12-hole design offers several advantages over a previously developed, 18-hole, nearly omni-directional probe. The probe is optimized in the sense that, regardless of the flow direction, it allows calculation of the 4 unknown flow quantities, i.e. the two flow angles, the velocity magnitude and the static pressure, with the minimum necessary number of holes/ports on the probe tip. This probe also has a non-conventional arrangement of its pressure ports and therefore the new calibration and data-reduction algorithms can be effectively employed. With theoretically generated pressure data for the 12-hole probe, the coefficient definitions are analyzed and found to be well-behaved.
3

Blast hole logging

Mack, Gary W. January 1983 (has links)
No description available.
4

Extended objects, solitons and Bogomol'nyi bounds

London, Lee Alexander James January 1994 (has links)
No description available.
5

Tropospheric chemistry of halogenated organic compounds

Kinnison, David J. A. January 1994 (has links)
No description available.
6

Two problems relating to cosmic censorship

Needham, T. January 1986 (has links)
No description available.
7

Re-envisioning the Kimberley Mine Museum:De Beers’ Big Hole Project

Brown, Marj 09 February 2006 (has links)
Master of Arts in Heritage - Heritage Studies / The diamond company De Beers is in the process of re-designing the Kimberley Mine Museum – a site marking the very beginnings of South Africa’s industrial history. The development of the new attraction will be subject to various forces and considerations which will impact on how the museum will reflect the history of the city, of its people, and of De Beers itself. These forces include the traditional educational function of a museum, the historical functions of displaying social history, possible new political expectations of a more inclusive social history being displayed, the corporate ownership of this attraction, and commercial pressures. The main aim of the research will be to investigate ways in which an inclusive social history is accommodated in the planning process for the new museum.
8

Horizontal directional spectrum estimation of the Heard Island transmissions

Traykovski, Peter January 1994 (has links)
Thesis (Ocean. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, and Woods Hole Oceanographic Institution, 1994. / Includes bibliographical references. / by Peter Traykovski. / Ocean.E.
9

System identification and state reconstruction for autonomous navigation of an underwater vehicle in an acoustic net

Morrison, Archie Todd January 1994 (has links)
Thesis (Ocean. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994. / GRSN 683373 / Includes bibliographical references (leaves 202-205). / by Archie Todd Morrison, III / Ocean.E.
10

Refinement and application of new paleotemperature estimation technique

Sikes, Elisabeth Lynn January 1990 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1990. / Includes bibliographical references (leaves 98-109). / by Elisabeth Lynn Sikes. / Ph.D.

Page generated in 0.0388 seconds