Grassland/Atmosphere Response to Changing Climate: Coupling Regional and Local Scales. Final Report (open access)

Grassland/Atmosphere Response to Changing Climate: Coupling Regional and Local Scales. Final Report

The objectives of the study were: to evaluate the response of grassland ecosystems to atmospheric change at regional and site scales, and to develop multiscaled modeling systems to relate ecological and atmospheric models with different spatial and temporal resolutions. A menu-driven shell was developed to facilitate use of models at different temporal scales and to facilitate exchange information between models at different temporal scales. A detailed ecosystem model predicted that C{sub 3} temperate grasslands wig respond more strongly to elevated CO{sub 2} than temperate C{sub 4} grasslands in the short-term while a large positive N-PP response was predicted for a C{sub 4} Kenyan grassland. Long-term climate change scenarios produced either decreases or increases in Colorado plant productivity (NPP) depending on rainfall, but uniform increases in N-PP were predicted in Kenya. Elevated CO{sub 2} is likely to have little effect on ecosystem carbon storage in Colorado while it will increase carbon storage in Kenya. A synoptic climate classification processor (SCP) was developed to evaluate results of GCM climate sensitivity experiments. Roughly 80% agreement was achieved with manual classifications. Comparison of lx and 2xCO{sub 2} GCM Simulations revealed relatively small differences.
Date: October 1, 1993
Creator: Coughenour, M. B.; Kittel, T. G. F.; Pielke, R. A. & Eastman, J.
System: The UNT Digital Library
Development of a gas-to-particle conversion model for use in three-dimensional global sulfur budget studies. Final report, 1 August 1991--30 June 1992 (open access)

Development of a gas-to-particle conversion model for use in three-dimensional global sulfur budget studies. Final report, 1 August 1991--30 June 1992

A fully-parameterized model for the formation and growth of aerosols via gas-to-particle conversion has been developed and tested. A particularly significant contribution is a new method for the prediction of numbers of particles nucleated using information on the vapor source rate, relative humidity, and preexisting aerosol alone, thus eliminating the need to solve a system of coupled ODEs. Preliminary tests indicate substantial reduction in computational costs, but it is recommended that the BIMODAM model be incorporated into a large-scale model of the sulfur cycle in order to more fully test its computational feasibility.
Date: August 1, 1993
Creator: Kreidenweis, S. M.
System: The UNT Digital Library
Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems (open access)

Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems

Focus has been mainly on preparation and characterization of triply bridged dinuclear complexes containing a tris-2-2'- bipyridineruthenium chromophore and a second tris-bipyridine metal complex which is to serve as electron donor or acceptor, and of linked RuL[sub 3]-containing D-C-A complexes where D is a phenothiazine donor and A is a diquat type acceptor. (DLC)
Date: June 1, 1993
Creator: Elliott, C.M.
System: The UNT Digital Library
Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems. Progress Report, September 1, 1993--May 31, 1993 (open access)

Photoinduced Charge Separation in Linked Donor-Chromophore-Acceptor Systems. Progress Report, September 1, 1993--May 31, 1993

Focus has been mainly on preparation and characterization of triply bridged dinuclear complexes containing a tris-2-2`- bipyridineruthenium chromophore and a second tris-bipyridine metal complex which is to serve as electron donor or acceptor, and of linked RuL{sub 3}-containing D-C-A complexes where D is a phenothiazine donor and A is a diquat type acceptor. (DLC)
Date: June 1, 1993
Creator: Elliott, C. M.
System: The UNT Digital Library
Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes (open access)

Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes

The report is divided into: vibrational models for surface ethylidenes (on catalyst surfaces); alpha vs beta hydrogen elimination in formation of propene from an osmacyclobutane; mechanism of formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; structure of Os(CO)[sub 4](C[sub 2]H[sub 4]), an osmacyclopropane; and reaction of [mu]-oxobis [(trifluoromethanesulfanato) (phenyl)iodine(III)] with Group 14 propargyl derivatives and a propargyl ether. 16 refs, figs.
Date: May 1, 1993
Creator: Norton, J.R.
System: The UNT Digital Library
Diosmacycloalkanes as Models for the Formation of Hydrocarbons From Surface Methylenes. Progress Report, November 1, 1992--October 31, 1993 (open access)

Diosmacycloalkanes as Models for the Formation of Hydrocarbons From Surface Methylenes. Progress Report, November 1, 1992--October 31, 1993

The report is divided into: vibrational models for surface ethylidenes (on catalyst surfaces); alpha vs beta hydrogen elimination in formation of propene from an osmacyclobutane; mechanism of formation and fragmentation of diosmacyclobutanes; reaction of dienes and allenes with diosmacyclobutanes; structure of Os(CO){sub 4}(C{sub 2}H{sub 4}), an osmacyclopropane; and reaction of {mu}-oxobis [(trifluoromethanesulfanato) (phenyl)iodine(III)] with Group 14 propargyl derivatives and a propargyl ether. 16 refs, figs.
Date: May 1, 1993
Creator: Norton, J. R.
System: The UNT Digital Library
Chemically modified electrodes and related solution studies (open access)

Chemically modified electrodes and related solution studies

This report is divided into 5 sections: Ru[sub 4]/Fe complexes of tetra(4[prime]-methyl-2,2[prime]-bipyridine)porphyrin--catalytic epoxidation of olefins; water oxidation catalysis by doubly linked [mu]-oxo ruthenium complexes; polymer films formed by oxidation of transition metal electrodes into solutions of bisbipyridinealkane ligands; polymer films containing [CpMo([mu]-S)][sub 2]S[sub 2]CHR dinuclear clusters;and conducting polymer films for catalyst incorporation.
Date: April 1, 1993
Creator: Elliott, C.M.
System: The UNT Digital Library
Chemically modified electrodes and related solution studies. Final technical report, January 15, 1991--January 14, 1992 (open access)

Chemically modified electrodes and related solution studies. Final technical report, January 15, 1991--January 14, 1992

This report is divided into 5 sections: Ru{sub 4}/Fe complexes of tetra(4{prime}-methyl-2,2{prime}-bipyridine)porphyrin--catalytic epoxidation of olefins; water oxidation catalysis by doubly linked {mu}-oxo ruthenium complexes; polymer films formed by oxidation of transition metal electrodes into solutions of bisbipyridinealkane ligands; polymer films containing [CpMo({mu}-S)]{sub 2}S{sub 2}CHR dinuclear clusters;and conducting polymer films for catalyst incorporation.
Date: April 1, 1993
Creator: Elliott, C. M.
System: The UNT Digital Library