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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.

Laser pulse amplification through a laser-cooled active plasma

Ghneim, Said Nimr, 1953- January 1988 (has links)
Recent advances in experimental laser cooling have shown the possibility of stopping an atomic beam using the light pressure force of a counter-propagating laser wave. As an application to laser cooling, it is proposed to build a single frequency cesium laser that has a narrow linewidth. Laser cooling techniques are used to cool an atomic beam of cesium to an average velocity of 5 m/s, corresponding to a temperature of 0.2°K. Expressions of the basic forces that a laser wave exerts on atoms are derived according to a semi-classical approach. The experimental problems and methods of avoiding these problems are treated in detail. A computer Monte-Carlo simulation is used to discuss the feasibility of building the proposed laser. This simulation was done for an ensemble of 10,000 atoms of cesium, and it included the effects of the gravitational force and the related experimental variables. The possibility of building single frequency lasers that use a cooled medium of noble gases, and many other applications of laser cooling are briefly discussed at the end of this work.

Plate-reinforced composite coupling beams experimental and numerical studies /

Lam, Wai-yin. January 2006 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Response of reinforced concrete elements and structures following loss of load bearing elements a dissertation /

Bazan, Marlon Luis. January 1900 (has links)
Title from title page (April 27, 2010) Graduate School of Engineering. Dept. of Civil and Environmental Engineering. Includes bibliographical references (p. 293-297).

Theory and design of a new submillimeter magnetically guided positron beam at the University of Hong Kong

Kwan, Pui-ying, Rebecca., 關珮瑩. January 2002 (has links)
published_or_final_version / Physics / Master / Master of Philosophy


Sentman, Judith Barlow. January 1983 (has links)
No description available.

Optimization of concrete beams with reliability constraints.

Harvey, Franklyn. January 1968 (has links)
No description available.

Low-velocity matter wave source for atom interferometry produced by Zeeman-tuned laser cooling and magneto-optic trapping

Mayer, Shannon K. 22 January 1997 (has links)
A continuous, low-velocity, nearly monochromatic atomic beam is created using laser cooling and two-dimensional magneto-optic trapping. Rubidium atoms from an effusive oven are slowed and cooled using Zeeman-tuned slowing. The scattering force from a counter-propagating, frequency-stabilized diode laser beam is used to decelerate the thermal beam of atoms to a velocity of ~ 20 m/s. A spatially varying magnetic field is used to Zeeman shift the resonance frequency of the atom to compensate for the changing Doppler shift, thereby keeping the slowing atoms resonant with the fixed frequency laser. This slowing process also cools the beam of atoms to a temperature of a few Kelvin. The slow beam of atoms is loaded into a two-dimensional magneto-optic trap or atomic funnel. The atoms are trapped along the axis of the funnel and experience a molassestype damping force in all three spatial dimensions. By frequency shifting the laser beams used to make the trap, the atoms are ejected at a controllable velocity. The continuous matter-wave source has a controllable beam velocity in the range of 2 to 15 m/s, longitudinal and transverse temperatures of approximately 500 ��K, and a flux of 3.4 x10��� atoms/s. At 10 m/s, the de Broglie wavelength of the beam is 0.5 nm. The spatial profile of the atomic beam was characterized 30 cm from the exit of the atomic funnel using a surface ionization detector. The low-velocity atomic beam is an ideal source for atom interferometry and a variety of applications in the field of atom optics. / Graduation date: 1997

An investigation of the applicability of limit design to cold-formed, light gage box beams

Householder, Jerry Lynn 08 1900 (has links)
No description available.

Optimization of concrete beams with reliability constraints.

Harvey, Franklyn. January 1968 (has links)
No description available.

Torsion in concrete framed structures /

Shepherd, Peter Noel. January 1975 (has links) (PDF)
Thesis (M.E.) -- University of Adelaide, Department of Civil Engineering, 1977.

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