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Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads featuring diquinone moieties. Technical progress report, September 1, 1991--30 April 1992

Description: This project involves the design, synthesis and photophysical study of complex molecular systems engineered to achieve long lived charge separated states by a biomimetic, photoinitiated multistep electron transfer process. The use of these artificial systems to investigate different electron and energy transfer strategies will allow the evolution of more efficient molecular devices for the gathering of light energy and its transformation into chemical potential energy. The three major aspects o… more
Date: April 30, 1992
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads. Technical progress report

Description: This research project involves the design, synthesis and study of molecules which mimic many of the important aspects of photosynthetic electron and energy transfer. The knowledge gained from the study of synthetic model systems which abstract features of the natural photosynthetic apparatus can be used to design artificial photosynthetic systems which employ the basic physics and chemistry of photosynthesis to help meet mankind`s energy needs. More specifically, the proposed models are designe… more
Date: April 12, 1988
Creator: Gust, J. D. Jr. & Moore, T. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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[Signal transduction in plant development: Chemical and biochemical approaches to receptor identification]. Progress report, [May 15, 1993--May 14, 1994]

Description: Progress is reported on studies concerning NAD(P)H-2,6-DMBQ oxidoreductase of Striga asiatica aimed at elucidating basic biochemical parameters of Striga. Reported studies include characterization of the enzyme, development of Striga molecular genetics, and development of a redox model for germination control.
Date: June 1, 1994
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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[Signal transduction in plant development: Chemical and biochemical approaches to receptor identification]. [Annual report, May 15, 1991--May 14, 1993]

Description: We have pursued inhibitor development and found that the inhibitors both the cyclopropyl- and oxiranequinones are intolerant of other substituents on the quinone nucleus and are only marginally tolerant to substitution on the three-membered rings. The tritiated cyclopropane and oxirane benzoquinones were prepared as labeled inhibitors. The material from each step of the fractionation procedure were evaluated for NAD(P)H 2,6-DMBQ oxidoreductase activity that was inhibited by the cyclopropyl and … more
Date: December 31, 1992
Creator: Lynn, D. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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DOE ER63951-3 Final Report: An Integrated Assessment of Geochemical and Community Structure Determinants of Metal Reduction Rates in Subsurface Sediments

Description: The objective of this research was to examine the importance of microbial community structure in influencing uranium reduction rates in subsurface sediments. If the redox state alone is the key to metal reduction, then any organisms that can utilize the oxygen and nitrate in the subsurface can change the geochemical conditions so metal reduction becomes an energetically favored reaction. Thus, community structure would not be critical in determining rates or extent of metal reduction unless c… more
Date: June 28, 2010
Creator: Pfiffner, Susan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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NABIR Assessment Element, Expanded Rapid, Comprehensive, Lipid Biomarker Analysis for Subsurface, Community Composition and Nutritional/Physiological Status as Monitors of Remediation and Detoxification Effectiveness

Description: NABIR funding at the University of Tennessee Center for Biomarker Analysis (CBA) has led to several key contributions to the investigation of bioremediation of metals and radionuclides. This lab has played an integral part in assessing microbial communities at the field scale at the ORNL FRC (Istok et al., 2004) and two UMTRA sites (Anderson et al., 2003, Chang et al., 2001). Our work over the period of the grant has resulted in 42-peer reviewed publications, 62 presentations (14 of which were … more
Date: September 14, 2005
Creator: White, David C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

[Signal transduction in plant development: Chemical and biochemical approaches to receptor identification]

Description: We have pursued inhibitor development and found that the inhibitors both the cyclopropyl- and oxiranequinones are intolerant of other substituents on the quinone nucleus and are only marginally tolerant to substitution on the three-membered rings. The tritiated cyclopropane and oxirane benzoquinones were prepared as labeled inhibitors. The material from each step of the fractionation procedure were evaluated for NAD(P)H 2,6-DMBQ oxidoreductase activity that was inhibited by the cyclopropyl and … more
Date: January 1, 1992
Creator: Lynn, D.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Radiation Laboratory quarterly report, January 1, 1978--March 31, 1978. NDRL--1877

Description: Progress in various studies is reported including studies on: vapor phase structures of inorganic salts; solvated electrons; exchange perturbation theory for many-electron interactions; concept of orbital following; calculation of vibrational form factors in electron impact excitation; limiting behavior of molecule-molecule inelastic collision amplitude at zero momentum transfer; partially diffusion-controlled reactions of isolated pair in condensed media; field-dependent mobilities, T-R energy… more
Date: April 12, 1978
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Chlorophyll-quinone photochemistry in liposomes: mechanisms of radical formation and decay

Description: Laser flash photolysis has been used to investigate the mechanism of formation and decay of the radical species generated by light induced electron transfer from chlorophyll a triplet to quinone in egg phosphatidyl choline bilayer vesicles. Chlorophyll triplet quenching by quinone is controlled by diffusion occurring within the bilayer membrane and reflects bilayer viscosity. Radical formation via separation of the intermediate ion pair is also inhibited by increased bilayer viscosity. Cooperat… more
Date: January 1, 1980
Creator: Hurley, J.K. & Tollin, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electron flow through plastoquinone and cytochromes b/sub 6/ and f in chloroplasts

Description: With dark-adapted chlorplasts in which the plastoquinone is oxidized a partial reduction of cytochrome b/sub 6/ is obtained upon illumination with a pair of short saturating flashes. The second flash of the pair is much more effective than the first flash, and the reduction is inhibited by the system II inhibitor diuron. When the plastoquinone pool is reduced both the reduction and the oxidation of cytochrome b/sub 6/ are accelerated. The cytochrome b/sub 6/ oxidation appears to proceed in asso… more
Date: January 1, 1978
Creator: Velthuys, B.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads. Technical progress report, 1989

Description: This research project involves the design, synthesis and study of molecules which mimic many of the important aspects of photosynthetic electron and energy transfer. Specifically, the molecules are designed to mimic the following aspects of natural photosynthetic multistep electron transfer: electron donation from a tetrapyrrole excited singlet state, electron transfer between tetrapyrroles, electron transfer from tetrapyrroles to quinones, and electron transfer between quinones with different … more
Date: April 12, 1989
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Free radicals in biological energy conversion: EPR studies of model systems. Final report. [Mechanism of chlorophyll participation in photosynthesis]

Description: Energy conversion in photosynthesis is known to proceed via light-induced one-electron transfer reactions involving chlorophyll and electron donors and acceptors. Although the chemical identities of all of the components have not as yet been elucidated, considerable evidence has been accumulated which points to quinones (Q) as primary electron acceptors in both green plants and bacterial photosynthesis. Furthermore, it has been established that the initial photoprocess leads to the formation of… more
Date: August 31, 1976
Creator: Tollin, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Preparation of polymer-modified electrodes: A literature and experimental study

Description: A literature review is presented on the field of polymer modified electrodes which can be electrochemically generated. It is suggested that a possible application of these polymer modified electrodes is as a regeneratable catalysis packing material for use in couter-current exchange columns. Secondly, there is a presentation of experimental results dealing with possible electrode modification using difluoro- and dimethyl- phenols and fluorinated derivatives of styrene, benzoquinone and hydroqui… more
Date: May 1, 1991
Creator: Jayanta, Pat Siripastr & Ishida, Takanobu.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Pacific Northwest Laboratory annual report for 1983 to the DOE Office of Energy Research. Part 3. Atmospheric sciences

Description: The goals of atmospheric research at Pacific Northwest Laboratory (PNL) are to assess, describe and predict the nature and fate of atmospheric contaminants and to study the impacts of contaminants on local, regional and global climates. The contaminants being investigated are those resulting from the development and use of conventional energy resources (coal, gas, oil, and nuclear power) as well as alternative energy resources. The description of atmospheric research at PNL is organized in term… more
Date: February 1, 1984
Creator: Elderkin, C. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads

Description: This project involves the design, synthesis and study of molecules which mimic some of the important aspects of photosynthetic electron and energy transfer. This research project is leading to a better understanding of the energy conserving steps of photosynthesis via the study of synthetic model systems which abstract features of the natural photosynthetic apparatus. The knowledge gained from these studies will aid in the design of artificial photosynthetic reaction centers which employ the ba… more
Date: March 1993
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A novel synthesis of polyesters containing hexa-(tert-butylhydroquinone)cyclotriphosphazene

Description: The majority of polyphosphazene material research has concentrated on the linear polymer configuration. However, this represents only one of three potential backbone configurations for phosphazenes. Linear polymers are formed either directly from phosphorus and nitrogen containing precursors or from the ring opening polymerization of hexachlorocyclotriphosphazene. Two other backbone structures can be formed from hexachlorocyclotriphosphazene cyclolinear and cyclomatrix. Cyclolinear are the leas… more
Date: March 26, 2000
Creator: Stewart, F. F.; Luther, T. A.; Harrup, M. K. & Lash, R. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

"Quadrupoled" materials for second-order nonlinear optics

Description: We describe a new approach to second-order nonlinear optical materials, namely quadrupoling. This approach is valid in the regime of Kleinman (full permutation) symmetry breaking, and thus requires a two- or three dimensional microscopic nonlinearity at wavelengths away from material resonances. This {open_quotes}quadrupolar{close_quotes} nonlinearity arises from the second rank pseudotensor of the rotationally invariant representation of the second-order nonlinear optical tensor. We have exper… more
Date: October 1, 1997
Creator: Hubbard, S. F.; Petschek, R. G. & Singer, K. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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