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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.
41

The conductivity produced in neon and in helium by irradiation with their own resonance radiations and the effect of foreign gases on this conductivity

Smith, Robert Worth, January 1900 (has links)
Thesis (Ph. D.)--University of Michigan, 1933. / Cover title. Reprinted from the Physical review, vol. 47, no. 6, March 15, 1935."
42

On the motion of a sphere of oil through carbon dioxide and an exact determination of the coefficient of viscosity of that gas by the oil dorp [i.e. drop] method ... /

Lassalle, Leo Joseph. January 1900 (has links)
Thesis (Ph. D.)--University of Chicago, 1917. / "Reprinted from the Physical review, N.S., Vol. XVII, No. 3, March, 1921." Includes bibliographical references. Also available on the Internet.
43

Multi-photon ionisation of gases in laser beams

Scheffler, T. B. January 1970 (has links)
No description available.
44

Investigations on plasmas produced in electromagnetic shock tubes.

Cormack, George Douglas January 1962 (has links)
Electromagnetic shock tubes were used to generate plasmas having a number density of the order of 10¹⁷ per cm³ and an energy per particle of 1-3 ev. In the shock tubes employed, the driving current was passed via electrodes through a discharge at one end of the tube. The discharge gases that were driven down the shock tube plus the ambient gas that was picked up and heated constituted the plasma that was studied. Many workers have assumed that shock equations can describe the discontinuity at the front of the plasma. An investigation into the effects of changes in the geometry of the driver mechanism has disclosed that the luminosity structure that can be attributed to the discharge gases stays very close to the luminosity front. The amount of ambient gas that is entrained in front of the discharge gases is thus small. Therefore, some doubt exists about the applicability of the shock equations both in the present shock tube and in the electromagnetic shock tubes of other workers. The shape of the luminosity front of the plasma was found to be affected by the properties of the driving discharge, even at a time long after the driving current had ceased to flow. Instabilities of the discharge and contamination by electrode material were found to drastically affect the homogeneity of the plasma. The homogeneity and reproducibility of the plasma produced by a small-cathode driver were found to be fairly good. However, there was a large amount of contamination in the plasma. The plasma was used to investigate the electro-dynamic response of an inductive magnetohydrodynamic power generator. Expressions for the output power were derived and compared with the experimental results. The electrodynamical response of a novel electrode-type Bɵ magnetohydrodynamic power generator was calculated. In an experiment performed with this generator a magnetohydrodynamic Interaction was observed indicating that the plasma was transporting an azimuthal magnetic field. No output power was obtained. The probable cause for this was that the applied magnetic field was insufficient to break down the sheath on the electrodes. A low pressure spark gap switch suitable for use as a main switch and as a "crowbar" switch on a capacitor bank was developed. The switch was operated over a voltage range of 0.5 to 25 kV, at energies up to 4 kJ and currents up to 500 kA. Under normal operating conditions the triggering time was 40 nsec and the jitter approximately 10 nsec. The inductance of the main switch was 4 nH and the inductance of the crowbar switch was about 1 nH. Other contributions are presented on a wide-voltage-range open-air spark gap switch, high voltage trigger circuits and on the dynamics of the plasma in an electromagnetic shock tube. The latter consists of an elementary treatment of the electromagnetic acceleration processes and a proposal of a model for the decelerating plasma. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
45

Investigation of the feasibility of sensing transient velocity by means of gaseous ionization

Huang, Hsien-Lu January 1968 (has links)
Sensitivity S<sup>i</sup><sub>p</sub> is defined as the ratio of the fractional change of gas ionization current to the fractional change of gas pressure. A maximum obtainable sensitivity was calculated, S<sup>i</sup><sub>p</sub>]<sub>max</sub> = -0.309 A/B V, where A, B are constants for a given gas within a particular range of field-to-pressure ratio. Experiments were conducted to investigate the sensitivity of air and krypton under different combinations of voltage, electrode separation and primary electron source strength. A curie of tritium placed on the central portion of either electrode produced a constant initial emission current and a high sensitivity. Sensitivity could be increased by using a stronger current source, higher voltage and a larger electrode separation. Observed values of S<sup>i</sup><sub>p</sub> for high voltage at larger separation are greater than those expected even when breakdown occurs at a (pd) quite larger than the one for S<sup>i</sup><sub>p</sub>]<sub>max</sub>. The fractional pressure change, Δp/p, is independent of the initial pressure, p, and is greater for a heavier gas subject to the same acceleration, a fact which suggests the use of a heavier gas to obtain a higher fractional current change for the same sensitivity. Krypton behaves in a similar way as air in the system. Operating current level may be higher than 10⁻⁵ ampere if stronger source is used. There is a limit in the separation for a given source configuration. Further increase in S<sup>i</sup><sub>p</sub> and current level may be achieved through better design of the configuration and location of the current source between the electrodes. The fractional current change, Δi/i, depends more on Δp rather than on the initial operating pressure, p. From the experiment performed, it appears that a gas system will perform satisfactorily as a transient velocity gauge. / M.S.
46

Penning ionization reactions of metastable Ar(³P₀,₂), Ne(³P₀,₂) and He(2³S) with organic molecules in a flowing afterglow apparatus

Jones, Michael Thomas. January 1983 (has links)
Call number: LD2668 .T4 1983 J66 / Master of Science
47

Breakdown of a gas at microwave frequencies

January 1948 (has links)
Melvin A. Herlin and Sanborn C. Brown. / "May 3, 1948." / Army Signal Corps Contract No. W-36-039 sc-32037.
48

Some gaseous reactions under the influence of ionizing agents

Marks, Barnard Mitchell, Lind, Samuel C. Glockler, George, January 1900 (has links)
Thesis (PH. D.)--University of Minnesota, 1929. / Cover-title. Vita. The first article is from the Journal of physical chemistry, v. 33, no. 3, March 1929; the second is Preprint 59-5 of the Electrochemical society.
49

On measurements of the molecular cross section of gases (other than the inert gases) with respect to slow electrons [manuscript] / On envelope in which ms. is inserted: Mr H.L. Brose's thesis for D.Sc.degree [manuscript] / Thesis for D.Sc.degree [manuscript]

Brose, Henry L. (Henry Leopold), 1890-, University of Adelaide. Dept. of Physics January 1931 (has links)
Collective title supplied from typewritten manuscript of the thesis / Includes bibliographical references. / Incomplete (lacks pts. v-viii) / 15 items (14 items bound) : / Typescript, reprints / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Consists of a thesis (ms. typescript, hand written corrections) and reprints of collateral research papers submitted for the D.Sc. degree to the University of Adelaide by Brose / Thesis (D.Sc.)--University of Adelaide, 1931

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