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Physical And Chemical Characterization Of Single Atmospheric Aerosols: Laboratory Studies Of Interactions Of Acidic Trace Gases With Sea -Salt Aerosols, And, Development Efforts For An Aerosol Charging System Using A Corona Discharge, Matthew Brigham Loomis
Doctoral Dissertations
There has long been an interest for in situ analysis of single atmospheric aerosols. To this end, the Flytrap instrument was developed under a NASA Phase I and Phase II Small Business Innovative Research Grant. The centerpiece of the instrument was a spherical void electrodynamic levitator that was used to suspend and optically characterize the physical and chemical properties of individual aerosols. Physical measurements of the aerosols were conducted with the aid of a Mie scattering system while chemical characterization was conducted with a Raman spectroscopy microprobe. A large effort focused on development of a system for charging and trapping …
Resonant Wave-Ion Interactions In The Heliosphere: I. Interplanetary Traveling Shocks, Ii. Ion Heating And Acceleration In The Extended Corona, Bruce Edward Gordon
Resonant Wave-Ion Interactions In The Heliosphere: I. Interplanetary Traveling Shocks, Ii. Ion Heating And Acceleration In The Extended Corona, Bruce Edward Gordon
Doctoral Dissertations
In Part I we present a revised version of the self-consistent theory of ion diffusive shock acceleration and associated generation of hydromagnetic waves at a planar stationary shock. Coupled wave kinetic and energetic particle transport equations are solved numerically and compared with an analytical approximation similar to that derived by Lee [1982, 1983]. The analytical approximation provides an accurate representation of both the proton distribution and the wave intensity. Excellent agreement between the predicted wave magnetic power spectral density adjacent to the shock as a function of frequency and the wave spectrum measured by ISEE 3 at the November 11--12, …
A Survey Of Beam Asymmetries In Semi-Exclusive Electron Scattering On Helium-4 And Carbon-12, Dan Protopopescu
A Survey Of Beam Asymmetries In Semi-Exclusive Electron Scattering On Helium-4 And Carbon-12, Dan Protopopescu
Doctoral Dissertations
A study of the polarized electron beam asymmetry in semi-exclusive ( e, e'p) reactions on 4He and 12C over a large kinematic range has been performed. The beam asymmetry A'LT is related to the imaginary part of the longitudinal-transverse interference and therefore it vanishes in reactions proceeding through a channel with a single dominant mechanism. In quasifree nucleon knockout, the helicity asymmetry provides an unambiguous signature for the interference between direct knockout and rescattering amplitudes. The data were taken in April--May 1999 using polarized beams of energies between 2.2 and 4.4 GeV, with the CEBAF Large Acceptance Spectrometer (CLAS) detector …
Mode Conversion And Wave -Particle Interaction Processes In The Solar Wind, Edisher Kh Kaghashvili
Mode Conversion And Wave -Particle Interaction Processes In The Solar Wind, Edisher Kh Kaghashvili
Doctoral Dissertations
This thesis presents the theoretical study of wave coupling and wave-particle interaction processes in the solar corona and wind. We first investigate the effect of an inhomogeneous velocity field on the propagation of waves in the solar atmosphere. We find that coupling between Alfven waves and fast magnetosonic waves can occur for parameters characterizing the coronal holes. For streamer conditions, the Alfven wave couples to the slow magnetosonic mode. In the inner corona, it seems that these two possible ways of coupling do not occur simultaneously in the same structures, while beyond 5--10 R⊙ , where the plasma beta is …
Characterization Of The Physical, Chemical, And Optical Properties Of Atmospheric Aerosol Particles In New Hampshire, John Frederick Slater
Characterization Of The Physical, Chemical, And Optical Properties Of Atmospheric Aerosol Particles In New Hampshire, John Frederick Slater
Doctoral Dissertations
Tropospheric aerosol particles directly affect the radiative budget of the Earth, and degrade visibility, by scattering and absorbing short-wavelength solar radiation. However, the radiative effect of aerosols is highly uncertain due to the non-uniform spatial distribution of the particles over Earth, their heterogeneous chemical composition, and their variable size. This dissertation quantifies some of the physical, chemical, and optical (radiative) properties of aerosols at different locations within New Hampshire (NH) from spring 2000 to fall 2001. During spring 2000, a 1-month study conducted at a mountaintop location adjacent to the White Mountain National Forest in northern NH showed that synoptic-scale …