Physical Sciences and Mathematics Commons^™

Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis

Chemistry & Biochemistry Theses & Dissertations

Catalysts composed of platinum and/or palladium on tin (IV) oxide supports, with and without silica gel, as well as catalysts composed of gold on manganese oxide, have been developed for the recombination of carbon monoxide and oxygen to form carbon dioxide for use in carbon dioxide lasers. A thermogravimetric method and a differential scanning calorimetric method have been developed for the thermal characterization of these catalysts. The mass loss data and the enthalpy changes determined as the catalysts lost water were then related to existing activity data for these catalysts. No relationship was found between the thermal data and the …

Nature Of The Si-N Bond In Silatranes, Mark S. Gordon, Marshall T. Carroll, Jan H. Jensen, Larry P. Davis, Larry W. Burggraf, R. Martin Guidry

Mark S. Gordon

Both ab initio and semiempirical calculations are used to investigate the structure and bonding in substituted silatranes. In agreement with gas-phase experiments, which fmd Si-N distances that are 0.25-0.35 A longer than those in the crystal phase, the Si-N distance (for example, in methylsilatrane) is predicted to be much larger than that observed in the crystal. Nonetheless, a bond critical point is found between Si and N, suggesting the existence of an Si-N bond in these compounds. It is found that the energy cost for constraining the Si-N distance in hydroxysilatrane to a value similar to that observed in the …

Evidence For An Unusual Kinetic Phenomenon In The Metallation Of Porphyrins, F. González-Vílchez, R. A. Vilaplana, Robert F. Pasternack

Chemistry & Biochemistry Faculty Works

Reaction of copper(II) with water soluble porphyrins (H₂porph) in the presence of ethylenediamine shows an unusual and so far unreported kinetic phenomenon that can be explained in terms of supramolecular assembly formation apparently involving all solute species as confirmed via light scattering and conductivity measurements.

A New Twist On Pseudorotation, Theresa L. Windus, Mark S. Gordon, Larry W. Burggraf, Larry P. Davis

Mark S. Gordon

For pentacoordinated structures in a trigonal bipyramidal ar· rangement, Berry1 proposed a "pseudorotation" mechanism whereby two such isomers can interconvert through a tetragonal transition state (TS). This Berry pseudorotation mechanism was demonstrated explicitly for SiH5- by following the MP22/6· 31G(d)3 minimum energy path4 (MEP).

Development Of Procedures To Determine The Fertilizer Requirements Of Annual Pasture Legumes Grown In Cereal Cropping Systems., B. H. Paynter

Experimental Summaries - Plant Research

Trials 88ME67, 88SC17, 90ME1 and 90ME2

Location: Merredin

To determine the phosphate (P) fertilizer requirements of burr medic on marginally acidic, medium textured soils and yellow serradella on acidic, light textured soils.

Trials 89ME52, 89ME55 and 86ME61

Location: Merredin

Determine the response of yellow serradella and burr medic to residual phosphate and freshly applied phosphate.

Trials 89ME50, 89ME54, 88ME67, 88SC17, 89ME60

Location: Merredin.

To measure the influence of different levels of pasture productivity (generated by different levels of P supply) and the different pasture legumes on subsequent wheat crops.

Seed Phosphorus In Wheat And Lupins, B. H. Paynter, K. Adcock, R. W. Bell, Tim Pope

Experimental Summaries - Plant Research

Trial 90NO119

Seed P in wheat.

Location: Greenhills.

Design: 2 applied P x 3 seed P x 4 replicates, sowing wheat (cv. Aroona) seed from 89N33 at 70 kg/ha on May 15, 1990.

Trial 90NO120

Seed P in wheat.

Location: York

Design: 2 applied from P x 3 seed P x 4 replicates, 89N33 at 70 kg/ha on May 25, 1990.

Trial 90NO117

Seed P in lupins

Location: Greenhills.

Design: 2 applied P x 3 seed P x 4 replicates, sowing lupins (cv. Gungurru) from 85BA35 at 100 kg/ha on May 15, 1990.

Trial 90NO118

Seed P in lupins.

Location: …

Trace Elements In Estuarine And Coastal Waters: U.S. Studies From 1986-1990, Gregory A. Cutter

OES Faculty Publications

The use of specialized analytical techniques, field studies, controlled laboratory experiments, and geochemical modeling have allowed U.S. investigators to expand our understanding of trace element cycling in coastal waters and estuaries. Considerable emphasis has been placed on quantifying the flux of trace elements within and through the coastal zone. In addition, substantial progress has been made in identifying the chemical speciation of many trace elements, providing a linkage between the geochemical and biochemical behavior of these elements. Another significant advance has been the use of trace elements as tracers of geochemical processes and water masses in the coastal environment.

Hydrogen Sulfide And Radon In And Over The Western North Atlantic Ocean, T. W. Andreae, Gregory A. Cutter, N. Hussain, J. Radford-Knoery, M. O. Andreae

OES Faculty Publications

Atmospheric measurements of radon and hydrogen sulfide, and seawater measurements of total sulfide, free sulfide, and carbonyl sulfide, were made on a cruise in the western North Atlantic Ocean (October 24 to November 9, 1989). Measured values for ²²²Rn ranged from 3 to 70 pCi m⁻³, those for atmospheric hydrogen sulfide from 1 to 85 parts per trillion, and those for dissolved total and free sulfide in seawater from 33 to 930 pmol L⁻¹ and 0 to 73 pmol L⁻¹, respectively. A positive correlation between ²²²Rn and atmospheric H₂S was observed. …

Second Coefficient Of Viscosity In Air, Robert L. Ash, Allan J. Zuckerwar, Zhonquan Zheng

Mechanical & Aerospace Engineering Faculty Publications

Acoustic attenuation measurements in air were analyzed in order to estimate the second coefficient of viscosity. Data over a temperature range of 11 C to 50 C and at relative humidities between 6 percent and 91 percent were used. This analysis showed that the second coefficient of viscosity varied between 1900 and 20,000 times larger than the dynamic or first coefficient of viscosity over the temperature and humidity range of the data. In addition, the data showed that the molecular relaxation effects, which are responsible for the magnitude of the second coefficient of viscosity, place severe limits on the use …