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The effect of rhenium, sulfur and alumina on the conversion of hydrocarbons over platinum single crystals: Surface science and catalytic studies

Description: Conversion reactions of hydrocarbons over Pt-Re model catalyst surfaces modified by sulfur and alumina have been studied. A plasma deposition source has been developed to deposit Pt, Re, and Al on metal substrates variable coverage in ultrahigh vacuum without excessive heating. Conversion of n-hexane was performed over the Re-covered Pt and Pt-covered Re surfaces. The presence of the second metal increased hydrogenolysis activity of both Pt-Re surfaces. Addition of sulfur on the model Catalyst … more
Date: April 1, 1992
Creator: Kim, C.
Partner: UNT Libraries Government Documents Department
open access

NMR studies of molecules in liquid crystals and graphite

Description: NMR experiments to measure proton dipole couplings were performed on a series of n-alkanes (n-hexane through n-decane) dissolved in nematic liquid crystals. Computer modeling of the experimental NMR-spectra was done using several different models for intermolecular interactions in these systems. The model of Photinos et al. was found to be best in describing the intermolecular interactions in these systems and can provide a statistical picture of the conformation and orientation of the alkane m… more
Date: June 1, 1992
Creator: Rosen, M. E.
Partner: UNT Libraries Government Documents Department
open access

The dynamics of azulene in liquids and compressed gases on ultrafast timescales

Description: The ultrafast dynamics of vibrationally hot ground state azulene molecules have been time resolved by picosecond transient absorption spectroscopy in a variety of solvents including hexane, chloromethanes, methanol, CClF{sub 3}, Xe and Kr. A high pressure optical cell was used to liquify gases for use as solvents and change their density and temperature, independently, over the entire liquid density range. Experimental results indicate the vibrational cooling rate is strongly solvent dependent,… more
Date: February 1, 1992
Creator: Schultz, K. E.
Partner: UNT Libraries Government Documents Department
open access

An Orifice Plate Pulse Column for Liquid-Liquid Extraction

Description: A study was made of the performance of an orifice plate pulse column which is essentially a spray column containing internal constrictions in the form of orifices. The chemical system studied was acetic acid-waterhexone, and the variables considered were pulse frequency, throughput, phase continuity, and direction of solute transfer. For comparison purposes, several runs were made with a conventional spray column. Curves are presented showing the effect of the column variables on the column eff… more
Date: August 23, 1954
Creator: O'Brien, D. C.
Partner: UNT Libraries Government Documents Department
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