Search Results

RECOVERY AND SEQUESTRATION OF CO2 FROM STATIONARY COMBUSTION SYSTEMS BY PHOTOSYNTHESIS OF MICROALGAE

Description: Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 January to 31 March 2001 in which Aquasearch tested 24 different species of microalgae for growth at three different temperatures. Eleven species were analyzed for the presence of high-value pigments. Most of the algae analyzed were good sources of industrially valuable pigments. Analysis of the methods for introducing and dissolving CO{sub 2} in the commercial bioreactor was begun this quarter.
Date: May 1, 2001
Creator: Nakamura, Dr. T. & Senior, Dr. C.L.
Partner: UNT Libraries Government Documents Department

Thenature of marbled Terra Sigillata slips: a combined mu XRF and mu XRD investigation

Description: In addition to the red terra sigillata production, the largest Gallic workshop (La Graufesenque) made a special type of terra sigillata, called 'marbled' by the archaeologists. Produced exclusively on this site, this pottery is characterized by a surface finish made of a mixture of yellow and red slips. Because the two slips are intimately mixed, it is difficult to obtain the precise composition of one of the two constituents without contamination by the other. In order to obtain very precise correlation at the appropriate scale between the color aspect and the element and mineralogical phase distributions in the slip, combined electron microprobe, x-ray micro spectroscopies and micro diffraction on cross sectional samples were performed. The aim is to discover how potters were able to produce this unique type of terra sigillata and especially this slip showing an intense yellow color. Results show that the yellow component of marbled sigillata was made from a titanium-rich clay preparation. The color is related to the formation of a pseudobrookite (TiFe2O5) phase in the yellow part of the slip, the main characteristics of that structure being considered nowadays as essential for the fabrication of stable yellow ceramic pigments. Its physical properties such as high refractive indices and a melting point higher than that of most silicates widely used as ceramic colorants are indeed determinant for this kind of applications. Finally, the red parts have a similar composition (elementary and mineralogical) to the one of standard red slip.
Date: January 31, 2009
Creator: Leon, Yoanna; Sciau, Philippe; Goudeau, Philippe; Tamura, Nobumichi; Webb, Sam & Mehta, Apurva
Partner: UNT Libraries Government Documents Department

PS2004 Light-harvesting Systems Workshop

Description: This special issue of the international scientific research journal Photosynthesis Research consists of 25 original peer-reviewed contributions from participants in the PS 2004 Lisht-Harvesting Systems Workshop. This workshop was held from 26-29, 2004 at Hotel Le Chantecler, Sainte-Adele, Quebec, Canada. The workshop was a satellite meeting of the XIII International Congress on Photosynthesis held August 29-September 3, 2004 in Montreal, Canada. The workshope dealt with all types of photosynthetic antenna systems and types of organisms, including anoxygenic photosynthetic bacteria, cyanobacteria, algae and higher plants, as well as in vitro studies of isolated pigments. This collection of papers is a good representation of the highly interdisciplinary nature of modern research on photosynthetic antenna complexes, utilizing techniques of advanced spectroscopy, biochemistry, molecular biology, synthetic chemistry and structural determination to understand these diverse and elegant molecular complexes.
Date: November 1, 2005
Creator: Blankenship, Robert E.
Partner: UNT Libraries Government Documents Department

Underwater Coatings for Contamination Control

Description: The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included 1) Test Area North (TAN-607) with epoxy painted concrete walls; 2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; 3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and 4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55oF to 80oF dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: · Be easy to apply · Adhere well to the four surfaces of interest · Not change or have a negative impact on water chemistry or clarity · Not be hazardous in final applied form · Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the ...
Date: February 1, 2004
Creator: Tripp, Julia L.; Archibald, Kip; Phillips, Ann-Marie & Campbell, Joseph
Partner: UNT Libraries Government Documents Department

PHYTOPLANKTON AND BIOMASS DISTRIBUTION AT POTENTIAL OTEC SITES

Description: Net or large phytoplankton species composition and most phytoplankton abundance was measured at three OTEC sites. In the Gulf of Mexico and Hawaii, diatoms dominated while the blue-green algae Trichodesmium was most common at Puerto Rico. The species ratio of diatoms to dinoflagellates was approximately 1:1. The species diversity varied from site to site, Hawaii > Puerto Rico > Gulf of Mexico. Chlorophyll a, which is a measure of the pigment of all algae size ranges, showed a subsurface peak of 0.14-0.4 g per liter at 75 to 125 m. Occasional surface peaks up to 0.4 pg per liter occurred. Further refinement of collection techniques is needed to delineate the subtle environmental effects expected by OTEC plant discharges.
Date: June 1, 1979
Creator: Johnson, P.W. & Horne, A.J.
Partner: UNT Libraries Government Documents Department

Discovery of Unusual Minerals in Paleolithic Black Pigments from Lascaux (France) and Ekain (Spain)

Description: Analyses of archaeological materials aim to rediscover the know-how of Prehistoric people by determining the nature of the painting matter, its preparation mode, and the geographic origin of its raw materials. This study deals with identification of manganese oxides in black pigments by micro-XANES (X-ray absorption near-edge structure) based on previous TEM (transmission electron microscopy) studies. Complex mixtures of the manganese oxides studied are present in some of mankind's oldest known paintings, namely those from the caves of Lascaux (Dordogne, France) and Ekain (Basque country, Spain). Scarce manganese oxide minerals, including groutite, hausmannite, and manganite, were found for the first time in Paleolithic art at these archaeological sites. Because there are no known deposits of such minerals in these areas, more distant origins and trade routes are inferred. The closest known Mn-rich geological province for Lascaux is the central Pyrenees, which is {approx} 250 km from the Dordogne area.
Date: December 13, 2006
Creator: Chalmin, E.; U., /Marne la Vallee; Farges, F.; /Marne l Vallee U. /Museum Nat. Hist., Paris /Stanford U., Geo. Environ. Sci.; Vignaud, C.; /Unknown et al.
Partner: UNT Libraries Government Documents Department

Smart Surfaces: New Coatings & Paints with Radiation Detection Functionality

Description: Paints are being developed and tested that might ultimately be able to detect radiological agents in the environment by incorporating special pigments into an organic polymeric binder that can be applied as a paint or coatings. These paints detect radioactive sources and contaminants with inorganic or organic scintillation or thermo-luminescent pigments, which are selected based upon the radiation ({alpha}, {beta}, {gamma} or n) to be detected, and are shown in Figure 1.
Date: March 12, 2007
Creator: Farmer, J & Choi, J
Partner: UNT Libraries Government Documents Department

BEST: Bilingual environmental science training, Grades 3--4

Description: This booklet is one of a series of bilingual guides to environmental-science learning activities for students to do at home. Lesson objectives, materials required, procedure, vocabulary, and subjects integrated into the lesson are described in English for each lesson. A bilingual glossary, alphabetized by English entries, with Spanish equivalents and definitions in both English and Spanish, follows the lesson descriptions, and is itself followed by a bibliography of English-language references with annotations in English. This booklet includes descriptions of ten lessons that cover the following topics: the identification of primary and secondary colors in the environment; recognizing the basic food tastes; the variety of colors that can be made by crushing plant parts; the variety of animal life present in common soil; animal tracks; evidence of plant and animal life in the local environment; recycling, reducing, and composting as alternative means of garbage disposal; waste associated with packaging; paper- recycling principles; and how organic waste can be composted into usable soil. 2 figs.
Date: March 1, 1996
Partner: UNT Libraries Government Documents Department

Replacemernt of thermally produced calcined clay with chemically structured pigments and methods for the same, quarterly report, January 1, 1995-April 1, 1995

Description: The business objective is to manufacture an economically viable chemically structured clay to replace thermally structured calcined clay. The technology will provide substantial benefit in paper coating. The structured pigment containing 90% clay and 10% TiO2 vs the loose blend of these materials as a filler for paper was evaluated. A plan to improve the permanence of the structured pigment using dual functional dispersed pigments is in place. The cationic dispersant for TiO2 will also be a binder. Spray drying will be use to fix the structure of the internally bound structured pigment.
Date: April 25, 1995
Creator: Whalen-Shaw, M.
Partner: UNT Libraries Government Documents Department

[Replacement of thermally produced calcined clay with chemically structured pigments and methods for the same]. Quarterly report, April 1, 1995--August 1, 1995

Description: The objective is to license the present technology for replacing thermally structured clay (calcined clay) with chemically structured clay. Composite layered pigments using Titanium dioxide and {number_sign}1 standard clay have already been shown to have activity in replacing calcined clay. In this past quarter the effect of clay particle size and distribution as raw materials for making the layered pigment have been investigated.
Date: December 31, 1995
Creator: Whalen-Shaw, M.
Partner: UNT Libraries Government Documents Department

Replacement of thermally produced calcined clay with chemically structured pigments and methods for the same, Final technical report, Quarterly report, February 3, 1996-May 1, 1996

Description: The testing of control formulas was repeated due to instability of the TiO2 dispersion being used. Calcined clay controls were compared to the performance of layered pigments of the instant invention in coatings on brown natural kraft paperboard from Mead Corporation.
Date: December 31, 1996
Creator: Whalen-Shaw, M.
Partner: UNT Libraries Government Documents Department

Is Lutein a Physiologically Important Ligand for Transthyretin in Humans?

Description: Lutein and zeaxanthin are the only carotenoids accumulated in the macula of the human retina and are known as the macular pigments (MP). These pigments account for the yellow color of the macula and appear to play an important role in protecting against age-related macular degeneration (AMD). The uptake of lutein and zeaxanthin in human eyes is remarkably specific. It is likely that specific transport or binding proteins are involved. The objective is to determine whether transthyretin (TTR) is a transport protein in human plasma and could thus deliver lutein from the blood to the retina. In this study, they used a biosynthetic {sup 13}C-lutein tracer and gas chromatography-combustion interfaced-isotope ratio mass spectrometry (GCC-IRMS) to gain the requisite sensitivity to detect the minute amounts of lutein expected as a physiological ligand for human transthyretin. The biosynthetic {sup 13}C-labeled lutein tracer was purified from algae. Healthy women (n = 4) each ingested 1 mg of {sup 13}C-labeled lutein daily for 3 days and a blood sample was collected 24 hours after the final dose. Plasma TTR was isolated by retinol-binding protein (RBP)-sepharose affinity chromatography and extracted with chloroform. The {sup 13}C/{sup 12}C ratio in the TTR extract was measured by GCC-IRMS. There was no {sup 13}C-lutein enrichment in the pure TTR extract. This result indicated that lutein is not associated with TTR in human plasma after ingestion in physiological amounts. Some hydrophobic compounds with yellow color may bind to human TTR in the plasma. However, this association needs to be further proved by showing specificity. The study provides a new approach for carotenoid-binding protein studies using a stable isotope tracer method combined with the high precision of GCC-IRMS. The mechanism of selective transport, uptake, and accumulation of lutein in human macula remain to be determined.
Date: May 31, 2003
Creator: Chen, Liwei
Partner: UNT Libraries Government Documents Department

Artificially-structured photorefractive and biomimetic materials. Final report

Description: This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Organic materials have shown great promise for near term applications in electro-optic, photorefractive, and electroluminescent devices. Electro-optic materials are useful for fast optical switching, photorefractive materials are essential for optical computing and information storage; electroluminescence is the basis for light-emitting diodes (LEDs). Existing organic electro- optic and photorefractive materials require a breakthrough in techniques to control the microscopic molecular orientation while maintaining economical processing. Our unique approach addresses this problem by building ordered superlattices by molecular engineering. Existing organic LEDs suffer from device breakdown, probably catalyzed by interfacial defects. Our approach allows molecular level control of the electronic properties of the polymer interfaces by designing charge transport layers to isolate the active polymer layer. This project sought to create electro-optic and photorefractive materials by engineering rationally designed nonlinear molecular building blocks into multilayer thin films using self assembly techniques.
Date: September 1, 1996
Creator: McBranch, D.; Bishop, A.; Donohoe, R.; Heeger, A.; Li, D.; Maniloff, E. et al.
Partner: UNT Libraries Government Documents Department

The Effects of Color Concentrate in Polyolefins.

Description: Throughout history consumer products were generally manufactured from wood and metal. They either had to hold their natural color or become subject to painting. When plastics entered the industry, it was recognized for its ease of shaping, re-usability, physical properties and its low cost. One of plastics' greatest benefits is its ability to hold a given color from within allowing it to avoid use of paint. This paper will give a brief overview on the effects of pigments when incorporated in a polyolefin. It will provide a classification of the main types of pigments and how each effect the properties of the product through: crystallization, weatherability, opacity, coloristic values and of course viscosity.
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Date: December 2001
Creator: Flora, Paul
Partner: UNT Libraries

Theoretical Simulations and Ultrafast Pump-probe Spectroscopy Experiments in Pigment-protein Photosynthetic Complexes

Description: Theoretical simulations and ultrafast pump-probe laser spectroscopy experiments were used to study photosynthetic pigment-protein complexes and antennae found in green sulfur bacteria such as Prosthecochloris aestuarii, Chloroflexus aurantiacus, and Chlorobium tepidum. The work focused on understanding structure-function relationships in energy transfer processes in these complexes through experiments and trying to model that data as we tested our theoretical assumptions with calculations. Theoretical exciton calculations on tubular pigment aggregates yield electronic absorption spectra that are superimpositions of linear J-aggregate spectra. The electronic spectroscopy of BChl c/d/e antennae in light harvesting chlorosomes from Chloroflexus aurantiacus differs considerably from J-aggregate spectra. Strong symmetry breaking is needed if we hope to simulate the absorption spectra of the BChl c antenna. The theory for simulating absorption difference spectra in strongly coupled photosynthetic antenna is described, first for a relatively simple heterodimer, then for the general N-pigment system. The theory is applied to the Fenna-Matthews-Olson (FMO) BChl a protein trimers from Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from Chlorobium tepidum. Circular dichroism spectra of the FMO trimer are unusually sensitive to diagonal energy disorder. Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Anisotropic absorption difference spectroscopy measurements are less consistent with 21-pigment trimer simulations than 7-pigment monomer simulations which assume that the laser-prepared states are localized within a subunit of the trimer. Experimental anisotropies from real samples likely arise from statistical averaging over states with diagonal energies shifted by in homogeneous broadening and as such, are quite sensitive to diagonal energy disorder. The experimental anisotropies exhibit strong oscillations with {approximately}220 fs period for certain wavelengths in one-color absorption difference experiments. The oscillations only appear when the laser pulse spectrum overlaps both of the ...
Date: September 12, 2000
Creator: Buck, D.R.
Partner: UNT Libraries Government Documents Department

Microbial Metabolite Production for Accelerated Metal and Radionuclide Bioremediation (Microbial Metabolite Production Report)

Description: Biogeochemical activity is an ongoing and dynamic process due to bacterial activity in the subsurface. Bacteria contribute significantly to biotransformation of metals and radionuclides. As basic science reveals more information about specific mechanisms of bacterial-metal reduction, an even greater contribution of bacteria to biogeochemical activities is realized. An understanding and application of the mechanisms of metal and radionuclide reduction offers tremendous potential for development into bioremedial processes and technologies. Most bacteria are capable of biogeochemical transformation as a result of meeting nutrient requirements. These assimilatory mechanisms for metals transformation include production of small molecules that serve as electron shuttles for metal reduction. This contribution to biogeochemistry is small however due to only trace requirements for minerals by bacteria. Dissimilatory metal reducing bacteria (DMRB) reduce oxidized metals and insoluble mineral oxides as a means for biological energy production during growth. These types of bacteria offer considerable potential for bioremediation of environments contaminated with toxic metals and radionuclides because of the relatively large amount of metal biotransformation they require for growth. One of the mechanisms employed by some DMRB for electron transfer to insoluble metal oxides is melanin production. The electrochemical properties of melanin provide this polymeric, humic-type compound with electron shuttling properties. Melanin, specifically, pyomelanin, increases the rate and degree of metal reduction in DMRB as a function of pyomelanin concentration. Due to its electron shuttling behavior, only low femtogram quantities per cell are required to significantly increase metal reduction capacity of DMRB. Melanin production is not limited to DMRB. In fact melanin is one of the most common pigments produced by biological systems. Numerous soil microorganisms produce melanin, contributing to about 2-4 percent of the humic fraction of soils. Our recent work has shown that melanin production by one species of bacteria could be used by other species for metal ...
Date: September 21, 2004
Creator: TURICK, CHARLES
Partner: UNT Libraries Government Documents Department

Kinetics of Beta-14[14C] Carotene in a Human Subject Using Accelerator Mass Spectrometry

Description: {beta}-Carotene is a tetraterpenoid distributed widely throughout the plant kingdom. It is a member of a group of pigments referred to as carotenoids that have the distinction of serving as metabolic precursors to vitamin A in humans and many animals [1,2]. We used Accelerator Mass Spectrometry (AMS) [3] to determine the metabolic behavior of a physiologic oral dose of {beta}-[{sup 14}C]carotene (200 nanoCuries; 0.57 {micro}mol) in a healthy human subject. Serial blood specimens were collected for 210-d and complete urine and feces were collected for 17 and 10-d, respectively. Balance data indicated that the dose was 42% bioavailable. The absorbed {beta}-carotene was lost slowly via urine in accord with the slow body turnover of {beta}-carotene and vitamin A [4]. HPLC fractionation of plasma taken at early time points (0-24-h) showed the label was distributed between {beta}-carotene and retinyl esters (vitamin A) derived from intestinal metabolism.
Date: January 31, 2000
Creator: Dueker, S.R.; Lin, Y.; Follett, J.R.; Clifford, A.J. & Buchholz, B.A.
Partner: UNT Libraries Government Documents Department

THE PERFORMANCE OF A MOTOR, A SWITCH, AND TWO TYPES OF PRESSURE PICKUP IN A HIGH-GAMMA-FLUX ENVIRONMENT

Description: To determine the effects of gamma radiation upon transducers, switches, and motors, two test assemblies were irradiated in the ANL Gamma Irradiation Facility at levels of 1.50 x 10/sup 5/to 2.10 x 10/sup 6/ rad/hr to a total dose of 1.0 x 10/sup 9/ rad. The components tested were a motor, a straingage pressure pickup, a quartz pressure pickup, and a high-temperature switch. The performances of the straingage pickup and snap switch were highly satisfactory over the test period. The quartz pickup, however, exhibited a sensitivity to radiation which rendered it ineffective for use in such an environment. Radiation damage to the motor was manifest as degradation of insulation, and evaporation and condensation of some of the products of degradation upon the walls of the test containment shell. As a result, the motor lost power, indicating a need for insulation more resistant to gamma radiation. Radistion damage to paints, varnish, grease, and conventional insu lations was noted, but the extent of this effect was not considered detrimental to the test. (auth)
Date: June 1, 1961
Creator: Ayer, J.E. & Pokorny, G.J.
Partner: UNT Libraries Government Documents Department

Structure, Function and Reconstitution of Antenna Complexes from Green Photosynthetic Bacteria

Description: This project is concerned with the structure and function of the chlorosome antennas found in green photosynthetic bacteria. Chlorosomes are ellipsoidal structures attached to the cytoplasmic side of the inner cell membrane. These antenna complexes provide a very large absorption cross section for light capture. Evidence is overwhelming that the chlorosome represents a very different type of antenna from that found in any other photosynthetic system yet studied. It is now clear that chlorosomes do not contain traditional pigment-proteins, in which the pigments bind to specific sites on proteins. Instead, the chlorosome pigments are organized in vivo into pigment oligomers in which direct pigment-pigment interactions are of dominant importance. Our group has used a multidisciplinary approach to investigate this unique system, as well as the complexes that they directly interact with. Our work has included using model systems, numerous types of both steady-state and ultrafast spectroscopy, molecular biology, protein chemistry and X-ray crystallography. Details of our recent results using these approaches are given below and in the references. Numbers cited in the sections refer to DOE-sponsored publications that are listed below. Only publications dated 2001-2004 or later are included in this report. In addition to the primary literature reports, a comprehensive review of this area of research has been written as well as a commentary.
Date: August 10, 2005
Creator: Blankenship, Robert E.
Partner: UNT Libraries Government Documents Department