Science.gov

Sample records for abundant renewable natural

  1. Helium isotopic abundance variation in nature

    SciTech Connect

    Holden, N.E.

    1993-08-01

    The isotopic abundance of helium in nature has been reviewed. This atomic weight value is based on the value of helium in the atmosphere, which is invariant around the world and up to a distance of 100,000 feet. Helium does vary in natural gas, volcanic rocks and gases, ocean floor sediments, waters of various types and in radioactive minerals and ores due to {alpha} particle decay of radioactive nuclides.

  2. Will Abundant Natural Gas Solve Climate Change?

    NASA Astrophysics Data System (ADS)

    McJeon, H. C.; Edmonds, J.; Bauer, N.; Leon, C.; Fisher, B.; Flannery, B.; Hilaire, J.; Krey, V.; Marangoni, G.; Mi, R.; Riahi, K.; Rogner, H.; Tavoni, M.

    2015-12-01

    The rapid deployment of hydraulic fracturing and horizontal drilling technologies enabled the production of previously uneconomic shale gas resources in North America. Global deployment of these advanced gas production technologies could bring large influx of economically competitive unconventional gas resources to the energy system. It has been hoped that abundant natural gas substituting for coal could reduce carbon dioxide (CO2) emissions, which in turn could reduce climate forcing. Other researchers countered that the non-CO2 greenhouse gas (GHG) emissions associated with shale gas production make its lifecycle emissions higher than those of coal. In this study, we employ five state-of-the-art integrated assessment models (IAMs) of energy-economy-climate systems to assess the full impact of abundant gas on climate change. The models show large additional natural gas consumption up to +170% by 2050. The impact on CO2 emissions, however, is found to be much smaller (from -2% to +11%), and a majority of the models reported a small increase in climate forcing (from -0.3% to +7%) associated with the increased use of abundant gas. Our results show that while globally abundant gas may substantially change the future energy market equilibrium, it will not significantly mitigate climate change on its own in the absence of climate policies.

  3. Progress in renewable polymers from natural terpenes, terpenoids, and rosin.

    PubMed

    Wilbon, Perry A; Chu, Fuxiang; Tang, Chuanbing

    2013-01-11

    The development of sustainable renewable polymers from natural resources has increasingly gained attention from scientists, engineers as well as the general public and government agencies. This review covers recent progress in the field of renewable bio-based monomers and polymers from natural resources: terpenes, terpenoids, and rosin, which are a class of hydrocarbon-rich biomass with abundance and low cost, holding much potential for utilization as organic feedstocks for green plastics and composites. This review details polymerization and copolymerization of terpenes such as pinene, limonene, and myrcene and their derivatives, terpenoids including carvone and menthol, and rosin-derived monomers. The future direction on the utilization of these natural resources is discussed. PMID:23065943

  4. Flex fuel polygeneration: Integrating renewable natural gas

    NASA Astrophysics Data System (ADS)

    Kieffer, Matthew

    Flex Fuel Polygeneration (FFPG) is the use of multiple primary energy sources for the production of multiple energy carriers to achieve increased market opportunities. FFPG allows for adjustments in energy supply to meet market fluctuations and increase resiliency to contingencies such as weather disruptions, technological changes, and variations in supply of energy resources. In this study a FFPG plant is examined that uses a combination of the primary energy sources natural gas and renewable natural gas (RNG) derived from MSW and livestock manure and converts them into energy carriers of electricity and fuels through anaerobic digestion (AD), Fischer-Tropsch synthesis (FTS), and gas turbine cycles. Previous techno-economic analyses of conventional energy production plants are combined to obtain equipment and operating costs, and then the 20-year NPVs of the FFPG plant designs are evaluated by static and stochastic simulations. The effects of changing operating parameters are investigated, as well as the number of anaerobic digestion plants on the 20-year NPV of the FTS and FFPG systems.

  5. Challenges in Renewable Natural Resources: A Guide to Alternative Futures.

    ERIC Educational Resources Information Center

    Theobald, Robert

    First presented at a United States Department of Agriculture (USDA) conference on renewable resources, this material includes information and discussion on critical issues, policies, and future alternatives for natural resources in the United States. (CO)

  6. UNDERGRADUATE EDUCATION IN RENEWABLE NATURAL RESOURCES, AN ASSESSMENT.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC.

    REPORTED ARE THE RECOMMENDATIONS OF THE PANEL ON NATURAL RESOURCE SCIENCE OF THE COMMISSION ON EDUCATION IN AGRICULTURE AND NATURAL RESOURCES FOR IMPROVING UNDERGRADUATE EDUCATION OF SCIENTISTS, MANAGERS, AND OTHER PERSONS PROFESSIONALLY ENGAGED IN DEVELOPING, MANAGING, AND PROTECTING THE RENEWABLE NATURAL RESOURCES OF THE UNITED STATES. THE…

  7. Harvesting and replenishment policies for renewable natural resources

    USGS Publications Warehouse

    Douglas, Aaron J.; Johnson, Richard L.

    1993-01-01

    The current paper links the optimal intertemporal use of renewable natural resources to the harvesting activities of various economic agents. Previous contributions cite market forces as a causative factor inducing the extirpation of renewable natural resources. The analysis given here discusses investment in the stock of renewable resources and cites important examples of this activity. By introducing joint harvesting and replenishment strategies into a model of renewable resource use, the analysis adds descriptive reality and relevance to positive and normative discussions of renewable natural resource use. A high price for the yield or a high discount rate tend to diminish the size of the optimum stationary stock of the resource with a non-replenishment harvesting strategy. Optimal non-replenishment harvesting strategies for renewable natural resources will exhaustion or extirpation of the resource if the price of the yield or the discount rate are sufficiently large. However, the availability of a replenishment technology and the use of replenishment activities tends to buffer the resource against exhaustion or extirpation.

  8. Naturally designed strong, tough and renewable biocomposites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The discovery that natural fiber filled materials have increased sound absorbency has led to their use in various automotive applications. However, the impact on structural implications of these natural fibers has not yet been investigated. Plant maturity may influence cell stiffness, which may in...

  9. The Effect of Natural Gas Supply on US Renewable Energy and Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Shearer, C.; Bistline, J.; Inman, M.; Davis, S. J.

    2014-12-01

    Increased use of natural gas has been promoted as a means of decarbonizing the US power sector, because of superior generator efficiency and lower CO2 emissions per unit of electricity than coal. We model the effect of different gas supplies on the US power sector and greenhouse gas (GHG) emissions. Across a range of climate policies, we find that more abundant natural gas decreases use of both coal and renewable energy technologies in the future. Without a climate policy, overall energy use also increases as the gas supply increases. With reduced deployment of lower-carbon renewable energies and increased electricity consumption, the effect of higher gas supplies on GHG emissions is small: cumulative emissions 2013-2055 in our high gas supply scenario are 2% less than in our low gas supply scenario, when there are no new climate policies and a methane leakage rate of 1.5% is assumed. Assuming leakage rates of 0 or 3% does not substantially alter this finding. In our results, only climate policies bring about a significant reduction in future CO2 emissions within the US electricity sector. Our results suggest that without strong limits on GHG emissions or policies that explicitly encourage renewable energy, more abundant natural gas may actually slow the process of decarbonization, primarily by delaying deployment of renewable energy technologies.

  10. Review of dynamic optimization methods in renewable natural resource management

    USGS Publications Warehouse

    Williams, B.K.

    1989-01-01

    In recent years, the applications of dynamic optimization procedures in natural resource management have proliferated. A systematic review of these applications is given in terms of a number of optimization methodologies and natural resource systems. The applicability of the methods to renewable natural resource systems are compared in terms of system complexity, system size, and precision of the optimal solutions. Recommendations are made concerning the appropriate methods for certain kinds of biological resource problems.

  11. Exploring the Potential Business Case for Synergies Between Natural Gas and Renewable Energy

    SciTech Connect

    Cochran, J.; Zinaman, O.; Logan, J.; Arent, D.

    2014-02-01

    Natural gas and renewable energy each contribute to economic growth, energy independence, and carbon mitigation, sometimes independently and sometimes collectively. Often, natural gas and renewables are considered competitors in markets, such as those for bulk electricity. This paper attempts to address the question, 'Given near- and long-term needs for abundant, cleaner energy sources and decarbonization, how can more compelling business models be created so that these two domestic forms of energy work in greater concert?' This paper explores revenue opportunities that emerge from systems-level perspectives in 'bulk energy' (large-scale electricity and natural gas production, transmission, and trade) and four 'distribution edge' subsectors: industrial, residential, commercial, and transportation end uses.

  12. Chlorine-36 abundance in natural and synthetic perchlorate

    SciTech Connect

    Heikoop, Jeffrey M; Dale, M; Sturchio, Neil C; Caffee, M; Belosa, A D; Heraty, Jr., L J; Bohike, J K; Hatzinger, P B; Jackson, W A; Gu, B

    2009-01-01

    Perchlorate (ClO{sub 4}{sup -}) is ubiquitous in the environment. It occurs naturally as a product of atmospheric photochemical reactions, and is synthesized for military, aerospace, and industrial applications. Nitrate-enriched soils of the Atacama Desert (Chile) contain high concentrations of natural ClO{sub 4}{sup -}; nitrate produced from these soils has been exported worldwide since the mid-1800's for use in agriculture. The widespread introduction of synthetic and agricultural ClO{sub 4}{sup -} into the environment has complicated attempts to understand the geochemical cycle of ClO{sub 4}{sup -}. Natural ClO{sub 4}{sup -} samples from the southwestern United States have relatively high {sup 36}Cl abundances ({sup 36}Cl/Cl = 3,100 x 10{sup -15} to 28,800 x 10{sup -15}), compared with samples of synthetic ({sup 36}Cl/Cl = 0.0 x 10{sup -15} to 40 x 10{sup -15}) and Atacama Desert ({sup 36}Cl/Cl = 0.9 x 10{sup -15} to 590 x 10{sup -15}) ClO{sub 4}{sup -}. These data give a lower limit for the initial {sup 36}Cl abundance of natural ClO{sub 4}{sup -} and provide temporal and other constraints on its geochemical cycle.

  13. Paper Thermoelectrics: Merging Nanotechnology with Naturally Abundant Fibrous Material.

    PubMed

    Sun, Chengjun; Goharpey, Amir Hossein; Rai, Ayush; Zhang, Teng; Ko, Dong-Kyun

    2016-08-31

    The development of paper-based sensors, antennas, and energy-harvesting devices can transform the way electronic devices are manufactured and used. Herein we describe an approach to fabricate paper thermoelectric generators for the first time by directly impregnating naturally abundant cellulose materials with p- or n-type colloidal semiconductor quantum dots. We investigate Seebeck coefficients and electrical conductivities as a function of temperature between 300 and 400 K as well as in-plane thermal conductivities using Angstrom's method. We further demonstrate equipment-free fabrication of flexible thermoelectric modules using p- and n-type paper strips. Leveraged by paper's inherently low thermal conductivity and high flexibility, these paper modules have the potential to efficiently utilize heat available in natural and man-made environments by maximizing the thermal contact to heat sources of arbitrary geometry. PMID:27505304

  14. Diagonal free homonuclear correlation using heteronuclei at natural abundance.

    PubMed

    Baishya, Bikash

    2015-07-01

    Homonuclear correlated spectroscopy such as COSY and TOCSY provides crucial structural information. In all homonuclear correlation, the most intense peaks are represented by the diagonal. As a result, the useful cross peaks close to the diagonal get obscured by the huge tails of diagonal peaks. Herein, we show that by editing the proton magnetization by a 13C nucleus in natural abundance, it is possible to eliminate the inphase coherence or untransferred magnetization that leads to the diagonal peak while retaining the antiphase coherence or transferred magnetization required for creation of cross peak. After the coherence transfer step, the untransferred magnetization directly attached to 13C evolves under one bond heteronuclear coupling while the transferred transverse magnetization directly attached to remote 12C does not. As a result, the untransferred magnetization directly attached to 13C can be converted to an unobservable heteronuclear multiple quantum coherence leading to a diagonal free correlated spectrum with a sensitivity penalty of two orders of magnitude but comparable to HSQC kind of experiments at natural abundance. The method demonstrated for COSY and TOCSY allows all proton-proton correlations to be observed except the geminal proton-proton correlations. Further, protons directly attached to heteronuclei other than 13C must be scalar coupled to protons directly attached to 13C to have a detectable cross peak. PMID:26001137

  15. Diversity and abundance of phosphonate biosynthetic genes in nature

    PubMed Central

    Yu, Xiaomin; Doroghazi, James R.; Janga, Sarath C.; Zhang, Jun Kai; Circello, Benjamin; Griffin, Benjamin M.; Labeda, David P.; Metcalf, William W.

    2013-01-01

    Phosphonates, molecules containing direct carbon–phosphorus bonds, compose a structurally diverse class of natural products with interesting and useful biological properties. Although their synthesis in protozoa was discovered more than 50 y ago, the extent and diversity of phosphonate production in nature remains poorly characterized. The rearrangement of phosphoenolpyruvate (PEP) to phosphonopyruvate, catalyzed by the enzyme PEP mutase (PepM), is shared by the vast majority of known phosphonate biosynthetic pathways. Thus, the pepM gene can be used as a molecular marker to examine the occurrence and abundance of phosphonate-producing organisms. Based on the presence of this gene, phosphonate biosynthesis is common in microbes, with ∼5% of sequenced bacterial genomes and 7% of genome equivalents in metagenomic datasets carrying pepM homologs. Similarly, we detected the pepM gene in ∼5% of random actinomycete isolates. The pepM-containing gene neighborhoods from 25 of these isolates were cloned, sequenced, and compared with those found in sequenced genomes. PEP mutase sequence conservation is strongly correlated with conservation of other nearby genes, suggesting that the diversity of phosphonate biosynthetic pathways can be predicted by examining PEP mutase diversity. We used this approach to estimate the range of phosphonate biosynthetic pathways in nature, revealing dozens of discrete groups in pepM amplicons from local soils, whereas hundreds were observed in metagenomic datasets. Collectively, our analyses show that phosphonate biosynthesis is both diverse and relatively common in nature, suggesting that the role of phosphonate molecules in the biosphere may be more important than is often recognized. PMID:24297932

  16. 13 ENDOR studies of organic radicals in natural isotopic abundance

    NASA Astrophysics Data System (ADS)

    Kirste, Burkhard

    13C ENDOR studies of phenoxyls, galvinoxyls, triphenylmethyl radicals, nitroxides, and cyclosilane and semiquinone radical anions with natural isotopic distribution are reported. The method is described, and it is shown that 13C coupling constants can be measured precisely; in favorable cases even the determination of signs is possible by general TRIPLE resonance. Studies of the relaxation behavior of 13C ENDOR signals or measurements of hyperfine shifts in liquid-crystalline solutions yield information about dipolar hyperfine interactions and hence π spin populations which is of aid in assignments to molecular positions. Complete sets of 13C coupling constants have been determined for 2,4,6-tri- tert-butylphenoxyl and Coppinger's radical. For the central carbon atoms of tert-butyl groups, a Q parameter of Qτ-Bu C = -34 MHz is proposed, and for a 29Si atom in trimethylsilyl groups, QTMSSi = +49 MHz. Favorable conditions for natural-abundance 13C ENDOR experiments, e.g., small hyperfine anisotropies and use of deuterated compounds, and limitations of the method are discussed.

  17. Pathways to Decarbonization. Natural Gas and Renewable Energy. Lessons Learned from Energy System Stakeholders

    SciTech Connect

    Pless, Jacquelyn; Arent, Douglas J.; Logan, Jeffrey; Cochran, Jaquelin; Zinaman, Owen; Stark, Camila

    2015-04-30

    Ensuring the resilience, reliability, flexibility, and affordability of the U.S. electric grid is increasingly important as the country addresses climate change and an aging infrastructure. State and federal policy and actions by industry, non-profits, and others create a dynamic framework for achieving these goals. Three principle low-carbon generation technologies have formed the basis for multiple scenarios leading toward a low-carbon, resilient, and affordable power system. While there is no “silver bullet,” one avenue identified by key stakeholders is the opportunity to invest in natural gas (NG) and renewable resources, both of which offer abundant domestic resource bases and contribute to energy independence, carbon mitigation, and economic growth. NG and renewable electricity (RE) have traditionally competed for market share in the power sector, but there is a growing experience base and awareness for their synergistic use (Cochran et al. 2014). Building upon these observations and previous work, the Joint Institute for Strategic Energy Analysis (JISEA), in collaboration with the Center for the New Energy Economy and the Gas Technology Institute, convened a series of workshops in 2014 to explore NG and RE synergies in the U.S. power sector. This report captures key insights from the workshop series, Synergies of Natural Gas and Renewable Energy: 360 Degrees of Opportunity, as well as supporting economic valuation analyses conducted by JISEA researchers that quantify the value proposition of investing in NG and RE together as complements.

  18. Our Natural Resources: Basic Research Needs in Forestry and Renewable Natural Resources.

    ERIC Educational Resources Information Center

    National Task Force on Basic Research in Forestry and Renewable Natural Resources.

    This report examines basic research needs in forestry and renewable natural resources and determines benefits to be gained from greater investments in basic research. It was prepared by a group of 17 research scientists, each an accomplished investigator in one or more fields. Each contributor reflected on research needs within his own discipline…

  19. Production of Renewable Natural Gas from Waste Biomass

    NASA Astrophysics Data System (ADS)

    Kumar, Sachin; Suresh, S.; Arisutha, S.

    2013-03-01

    Biomass energy is expected to make a major contribution to the replacement of fossil fuels. Methane produced from biomass is referred to as bio-methane, green gas, bio-substitute natural gas or renewable natural gas (RNG) when it is used as a transport fuel. Research on upgrading of the cleaned producer gas to RNG is still ongoing. The present study deals with the conversion of woody biomass into fuels, RNG using gasifier. The various effects of parameters like temperature, pressure, and tar formation on conversion were also studied. The complete carbon conversion was observed at 480 °C and tar yield was significantly less. When biomass was gasified with and without catalyst at about 28 s residence time, ~75 % (w/w) and 88 % (w/w) carbon conversion for without and with catalyst was observed. The interest in RNG is growing; several initiatives to demonstrate the thermal-chemical conversion of biomass into methane and/or RNG are under development.

  20. Diversity and abundance of phosphonate biosynthetic genes in nature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphonates, molecules containing direct C-P bonds, comprise a structurally diverse class of natural products with interesting and useful biological properties. Although their synthesis in protozoa was discovered more than fifty years ago, the extent and diversity of phosphonate production in natur...

  1. Carbon and nitrogen biogeochemistry in the ocean: A study using stable isotope natural abundance

    NASA Technical Reports Server (NTRS)

    Rau, G. H.; Desmarais, David J.

    1985-01-01

    Determining the biogeochemical pathways traveled by carbon and nitrogen in the ocean is fundamental to the understanding of how the ocean participates in the cycling of these elements within the biosphere. Because biological production, metabolism, and respiration can significantly alter the natural abundance of C-13 and N-15, these abundances can provide important information about the nature of these biological processes and their variability in the marine environment. The research initially seeks to characterize the spatial and temporal patterns of stable isotope abundances in organic matter, and to relate these abundances to C and N biogeochemical processes within selected areas of the northeastern Pacific Ocean.

  2. Renewable Natural Resources/Agriculture Curriculum. Secondary and Postsecondary Articulated Curriculum.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

    This competency-based curriculum is designed to be a handbook for courses in renewable natural resources/agriculture in Alaska. It details the competencies, developed through a survey of renewable natural resources/agriculture employers in Alaska, that such occupations require. The handbook is organized in six sections. Section I introduces the…

  3. Transposases are the most abundant, most ubiquitous genes in nature

    PubMed Central

    Aziz, Ramy K.; Breitbart, Mya; Edwards, Robert A.

    2010-01-01

    Genes, like organisms, struggle for existence, and the most successful genes persist and widely disseminate in nature. The unbiased determination of the most successful genes requires access to sequence data from a wide range of phylogenetic taxa and ecosystems, which has finally become achievable thanks to the deluge of genomic and metagenomic sequences. Here, we analyzed 10 million protein-encoding genes and gene tags in sequenced bacterial, archaeal, eukaryotic and viral genomes and metagenomes, and our analysis demonstrates that genes encoding transposases are the most prevalent genes in nature. The finding that these genes, classically considered as selfish genes, outnumber essential or housekeeping genes suggests that they offer selective advantage to the genomes and ecosystems they inhabit, a hypothesis in agreement with an emerging body of literature. Their mobile nature not only promotes dissemination of transposable elements within and between genomes but also leads to mutations and rearrangements that can accelerate biological diversification and—consequently—evolution. By securing their own replication and dissemination, transposases guarantee to thrive so long as nucleic acid-based life forms exist. PMID:20215432

  4. Natural variability in abundance of prevalent soybean proteins.

    PubMed

    Natarajan, Savithiry S

    2010-12-01

    Soybean is an inexpensive source of protein for humans and animals. Genetic modifications (GMO) to soybean have become inevitable on two fronts, both quality and yield will need to improve to meet increasing global demand. To ensure the safety of the crop for consumers it is important to determine the natural variation in seed protein constituents as well as any unintended changes that may occur in the GMO as a result of genetic modification. Understanding the natural variation of seed proteins in wild and cultivated soybeans that have been used in conventional soybean breeding programs is critical for determining unintended protein expression in GMO soybeans. In recent years, proteomic technologies have been used as an effective analytical tool for examining modifications of protein profiles. We have standardized and applied these technologies to determine and quantify the spectrum of proteins present in soybean seed. We used two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), and liquid chromatography mass spectrometry (LC-MS) for the separation, quantification, and identification of different classes of soybean seed proteins. We have observed significant variations in different classes of proteins, including storage, allergen and anti-nutritional protein profiles, between non-GMO cultivated and wild soybean varieties. This information is useful for scientists and regulatory agencies to determine whether the unintended expression of proteins found in transgenic soybean is within the range of natural variation. PMID:20709130

  5. Opportunities for Synergy Between Natural Gas and Renewable Energy in the Electric Power and Transportation Sectors

    SciTech Connect

    Lee, A.; Zinaman, O.; Logan, J.

    2012-12-01

    Use of both natural gas and renewable energy has grown significantly in recent years. Both forms of energy have been touted as key elements of a transition to a cleaner and more secure energy future, but much of the current discourse considers each in isolation or concentrates on the competitive impacts of one on the other. This paper attempts, instead, to explore potential synergies of natural gas and renewable energy in the U.S. electric power and transportation sectors.

  6. Determining carbon-carbon connectivities in natural abundance organic powders using dipolar couplings.

    PubMed

    Dekhil, Myriam; Mollica, Giulia; Bonniot, Tristan Texier; Ziarelli, Fabio; Thureau, Pierre; Viel, Stéphane

    2016-06-30

    We present a solid-state NMR methodology capable of investigating the carbon skeleton of natural abundance organic powders. The methodology is based on the (13)C-(13)C dipolar coupling interaction and allows carbon-carbon connectivities to be unambiguously established for a wide range of organic solids. This methodology is particularly suitable for disordered solids, such as natural or synthetic macromolecules, which cannot be studied using conventional diffraction or NMR techniques. PMID:27319808

  7. Hyperpolarized NMR of plant and cancer cell extracts at natural abundance.

    PubMed

    Dumez, Jean-Nicolas; Milani, Jonas; Vuichoud, Basile; Bornet, Aurélien; Lalande-Martin, Julie; Tea, Illa; Yon, Maxime; Maucourt, Mickaël; Deborde, Catherine; Moing, Annick; Frydman, Lucio; Bodenhausen, Geoffrey; Jannin, Sami; Giraudeau, Patrick

    2015-09-01

    Natural abundance (13)C NMR spectra of biological extracts are recorded in a single scan provided that the samples are hyperpolarized by dissolution dynamic nuclear polarization combined with cross polarization. Heteronuclear 2D correlation spectra of hyperpolarized breast cancer cell extracts can also be obtained in a single scan. Hyperpolarized NMR of extracts opens many perspectives for metabolomics. PMID:26215673

  8. Natural abundance 17O DNP two-dimensional and surface-enhanced NMR spectroscopy

    DOE PAGESBeta

    Perras, Frédéric A.; Kobayashi, Takeshi; Pruski, Marek

    2015-06-22

    Due to its extremely low natural abundance and quadrupolar nature, the 17O nuclide is very rarely used for spectroscopic investigation of solids by NMR without isotope enrichment. Additionally, the applicability of dynamic nuclear polarization (DNP), which leads to sensitivity enhancements of 2 orders of magnitude, to 17O is wrought with challenges due to the lack of spin diffusion and low polarization transfer efficiency from 1H. Here, we demonstrate new DNP-based measurements that extend 17O solid-state NMR beyond its current capabilities. The use of the PRESTO technique instead of conventional 1H–17O cross-polarization greatly improves the sensitivity and enables the facile measurementmore » of undistorted line shapes and two-dimensional 1H–17O HETCOR NMR spectra as well as accurate internuclear distance measurements at natural abundance. This was applied for distinguishing hydrogen-bonded and lone 17O sites on the surface of silica gel; the one-dimensional spectrum of which could not be used to extract such detail. As a result, this greatly enhanced sensitivity has enabled, for the first time, the detection of surface hydroxyl sites on mesoporous silica at natural abundance, thereby extending the concept of DNP surface-enhanced NMR spectroscopy to the 17O nuclide.« less

  9. Natural Genetic Variation Influences Protein Abundances in C. elegans Developmental Signalling Pathways

    PubMed Central

    Singh, Kapil Dev; Roschitzki, Bernd; Snoek, L. Basten; Grossmann, Jonas; Zheng, Xue; Elvin, Mark; Kamkina, Polina; Schrimpf, Sabine P.; Poulin, Gino B.; Kammenga, Jan E.; Hengartner, Michael O.

    2016-01-01

    Complex traits, including common disease-related traits, are affected by many different genes that function in multiple pathways and networks. The apoptosis, MAPK, Notch, and Wnt signalling pathways play important roles in development and disease progression. At the moment we have a poor understanding of how allelic variation affects gene expression in these pathways at the level of translation. Here we report the effect of natural genetic variation on transcript and protein abundance involved in developmental signalling pathways in Caenorhabditis elegans. We used selected reaction monitoring to analyse proteins from the abovementioned four pathways in a set of recombinant inbred lines (RILs) generated from the wild-type strains N2 (Bristol) and CB4856 (Hawaii) to enable quantitative trait locus (QTL) mapping. About half of the cases from the 44 genes tested showed a statistically significant change in protein abundance between various strains, most of these were however very weak (below 1.3-fold change). We detected a distant QTL on the left arm of chromosome II that affected protein abundance of the phosphatidylserine receptor protein PSR-1, and two separate QTLs that influenced embryonic and ionizing radiation-induced apoptosis on chromosome IV. Our results demonstrate that natural variation in C. elegans is sufficient to cause significant changes in signalling pathways both at the gene expression (transcript and protein abundance) and phenotypic levels. PMID:26985669

  10. High-resolution NMR of hydrogen in organic solids by DNP enhanced natural abundance deuterium spectroscopy

    NASA Astrophysics Data System (ADS)

    Rossini, Aaron J.; Schlagnitweit, Judith; Lesage, Anne; Emsley, Lyndon

    2015-10-01

    We demonstrate that high field (9.4 T) dynamic nuclear polarization (DNP) at cryogenic (∼100 K) sample temperatures enables the rapid acquisition of natural abundance 1H-2H cross-polarization magic angle spinning (CPMAS) solid-state NMR spectra of organic solids. Spectra were obtained by impregnating substrates with a solution of the stable DNP polarizing agent TEKPol in tetrachloroethane. Tetrachloroethane is a non-solvent for the solids, and the unmodified substrates are then polarized through spin diffusion. High quality natural abundance 2H CPMAS spectra of histidine hydrochloride monohydrate, glycylglycine and theophylline were acquired in less than 2 h, providing direct access to hydrogen chemical shifts and quadrupolar couplings. The spectral resolution of the 2H solid-state NMR spectra is comparable to that of 1H spectra obtained with state of the art homonuclear decoupling techniques.

  11. Natural abundance high-resolution solid state 2 H NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Aliev, Abil E.; Harris, Kenneth D. M.; Apperley, David C.

    1994-08-01

    We report for the first time an approach for natural abundance solid state 2 H NMR spectroscopy involving magic angle sample spinning (MAS), high-power 1 H decoupling (HPPD) and 1 H- 2 H cross polarization (CP). Taking tetrakis(trimethylsilyl)silane (TTMSS), adamantane, 1-chloroadamantane, hexamethylbenzene (HMB), 2,2-dimethyl-1,3-propanediol (DMPD) and 2-hydroxymethyl-2-methyl-1,3-propanediol (HMPD) as examples, it has been shown that the combination of HPPD and MAS can be applied readily to study rotator phase solids, allowing isotropic peaks arising from chemically inequivalent 2 H nuclei to be resolved. For natural abundance samples of TTMSS and chloroadamantane, it has been shown that 2 H CP/HPPD/MAS NMR experiments, involving polarization transfer from 1 H to 2 H, may provide considerable sensitivity enhancement in comparison with single pulse experiments.

  12. Natural abundance high-resolution solid state 2 H NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Aliev, Abil E.; Harris, Kenneth D. M.; Apperley, David C.

    1994-08-01

    We report for the first time an approach for natural abundance solid state 2H NMR spectroscopy involving magic angle sample spinning (MAS), high-power 1H decoupling (HPPD) and 1H- 2H cross polarization (CP). Taking tetrakis(trimethylsilyl)silane (TTMSS), adamantane, 1-chloroadamantane, hexamethylbenzene (HMB), 2,2-dimethyl-1,3-propanediol (DMPD) and 2-hydroxymethyl-2-methyl-1,3-propanediol (HMPD) as examples, it has been shown that the combination of HPPD and MAS can be applied readily to study rotator phase solids, allowing isotropic peaks arising from chemically inequivalent 2H nuclei to be resolved. For natural abundance samples of TTMSS and chloroadamantane, it has been shown that 2H CP/HPPD/MAS NMR experiments, involving polarization transfer from 1H to 2H, may provide considerable sensitivity enhancement in comparison with single pulse experiments.

  13. Increased natural mortality at low abundance can generate an Allee effect in a marine fish

    PubMed Central

    Kuparinen, Anna; Hutchings, Jeffrey A.

    2014-01-01

    Negative density-dependent regulation of population dynamics promotes population growth at low abundance and is therefore vital for recovery following depletion. Inversely, any process that reduces the compensatory density-dependence of population growth can negatively affect recovery. Here, we show that increased adult mortality at low abundance can reverse compensatory population dynamics into its opposite—a demographic Allee effect. Northwest Atlantic cod (Gadus morhua) stocks collapsed dramatically in the early 1990s and have since shown little sign of recovery. Many experienced dramatic increases in natural mortality, ostensibly attributable in some populations to increased predation by seals. Our findings show that increased natural mortality of a magnitude observed for overfished cod stocks has been more than sufficient to fundamentally alter the dynamics of density-dependent population regulation. The demographic Allee effect generated by these changes can slow down or even impede the recovery of depleted populations even in the absence of fishing. PMID:26064531

  14. Increased natural mortality at low abundance can generate an Allee effect in a marine fish.

    PubMed

    Kuparinen, Anna; Hutchings, Jeffrey A

    2014-10-01

    Negative density-dependent regulation of population dynamics promotes population growth at low abundance and is therefore vital for recovery following depletion. Inversely, any process that reduces the compensatory density-dependence of population growth can negatively affect recovery. Here, we show that increased adult mortality at low abundance can reverse compensatory population dynamics into its opposite-a demographic Allee effect. Northwest Atlantic cod (Gadus morhua) stocks collapsed dramatically in the early 1990s and have since shown little sign of recovery. Many experienced dramatic increases in natural mortality, ostensibly attributable in some populations to increased predation by seals. Our findings show that increased natural mortality of a magnitude observed for overfished cod stocks has been more than sufficient to fundamentally alter the dynamics of density-dependent population regulation. The demographic Allee effect generated by these changes can slow down or even impede the recovery of depleted populations even in the absence of fishing. PMID:26064531

  15. High-resolution NMR of hydrogen in organic solids by DNP enhanced natural abundance deuterium spectroscopy.

    PubMed

    Rossini, Aaron J; Schlagnitweit, Judith; Lesage, Anne; Emsley, Lyndon

    2015-10-01

    We demonstrate that high field (9.4 T) dynamic nuclear polarization (DNP) at cryogenic (∼100 K) sample temperatures enables the rapid acquisition of natural abundance (1)H-(2)H cross-polarization magic angle spinning (CPMAS) solid-state NMR spectra of organic solids. Spectra were obtained by impregnating substrates with a solution of the stable DNP polarizing agent TEKPol in tetrachloroethane. Tetrachloroethane is a non-solvent for the solids, and the unmodified substrates are then polarized through spin diffusion. High quality natural abundance (2)H CPMAS spectra of histidine hydrochloride monohydrate, glycylglycine and theophylline were acquired in less than 2h, providing direct access to hydrogen chemical shifts and quadrupolar couplings. The spectral resolution of the (2)H solid-state NMR spectra is comparable to that of (1)H spectra obtained with state of the art homonuclear decoupling techniques. PMID:26363582

  16. Determination of lithium isotopes at natural abundance levels by atomic absorption spectrometry

    USGS Publications Warehouse

    Meier, A.L.

    1982-01-01

    The relationships of the absorption of 6Li and 7Li hollow cathode lamp emissions are used to determine lithium isotopic composition in the natural abundance range of geologic materials. Absorption was found to have a nonlinear dependence upon total lithium concentration and isotopic composition. A method using nonlinear equations to describe the relationship of the absorption of 6Li and 7Li lamp radiation is proposed as a means of calculating isotopic composition that is independent of total lithium concentration.

  17. Natural abundance 2H-ERETIC-NMR authentication of the origin of methyl salicylate.

    PubMed

    Le Grand, Flore; George, Gerard; Akoka, Serge

    2005-06-29

    Methyl salicylate is a compound currently used in the creation of many flavors. It can be obtained by synthesis or from two natural sources: essential oil of wintergreen and essential oil of sweet birch bark. Deuterium site-specific natural isotope abundance (A(i)) determination by NMR spectroscopy with the method of reference ERETIC ((2)H-ERETIC-NMR) has been applied to this compound. A(i) measurements have been performed on 19 samples of methyl salicylate from different origins, natural/synthetic and commercial/extracted. This study demonstrates that appropriate treatment performed on the data allows discrimination between synthetic and natural samples. Moreover, the representation of intramolecular ratios R(6/5) as a function of R(3/2) distinguishes between synthetics, wintergreen oils, and sweet birch bark oils. PMID:15969485

  18. The potential impact of renewable energy deployment on natural gas prices in New England

    SciTech Connect

    Wiser, Ryan; Bolinger, Mark

    2004-09-20

    Concerns about the price and supply of natural gas have deepened in recent years both nationally and in New England. Renewable energy (RE) technologies can directly hedge natural gas price risk by reducing the need to purchase variable-price natural gas-fired electricity generation, and replacing that generation with fixed-price renewable electricity supply. In addition to its direct contribution to price stability, an increasing number of studies show that renewable energy deployment can also put downward pressure on natural gas prices by reducing demand for gas among gas-fired generators. These gas price reductions are, in turn, expected to reduce electricity prices and--more importantly--directly reduce consumer natural gas bills. Many recent studies have found that this effect may be significant, substantially benefiting consumers. These studies are reviewed in the attached paper, published in the proceedings of a recent national energy conference. An important consideration is that--strictly speaking--this price reduction represents a consumer benefit that comes at the expense of producers; it therefore represents a wealth transfer, not a net gain in social welfare. That said, current concerns about the price and supply of natural gas suggest that policymakers may want to pursue actions that reduce the strain of high prices on consumer energy bills.

  19. Can Deployment of Renewable Energy and Energy Efficiency PutDownward Pressure on Natural Gas Prices

    SciTech Connect

    Wiser, Ryan; Bolinger, Mark

    2005-06-01

    High and volatile natural gas prices have increasingly led to calls for investments in renewable energy and energy efficiency. One line of argument is that deployment of these resources may lead to reductions in the demand for and price of natural gas. Many recent U.S.-based modeling studies have demonstrated that this effect could provide significant consumer savings. In this article we evaluate these studies, and benchmark their findings against economic theory, other modeling results, and a limited empirical literature. We find that many uncertainties remain regarding the absolute magnitude of this effect, and that the reduction in natural gas prices may not represent an increase in aggregate economic wealth. Nonetheless, we conclude that many of the studies of the impact of renewable energy and energy efficiency on natural gas prices appear to have represented this effect within reason, given current knowledge. These studies specifically suggest that a 1% reduction in U.S. natural gas demand could lead to long-term average wellhead price reductions of 0.8% to 2%, and that each megawatt-hour of renewable energy and energy efficiency may benefit natural gas consumers to the tune of at least $7.5 to $20.

  20. Effect of Environmental Factors on Cyanobacterial Abundance and Cyanotoxins Production in Natural and Drinking Water, Bangladesh.

    PubMed

    Affan, Abu; Khomavis, Hisham S; Al-Harbi, Salim Marzoog; Haque, Mahfuzul; Khan, Saleha

    2015-02-01

    Cyanobacterial blooms commonly appear during the summer months in ponds, lakes and reservoirs in Bangladesh. In these areas, fish mortality, odorous water and fish and human skin irritation and eye inflammation have been reported. The influence of physicochemical factors on the occurrence of cyanobacteria and its toxin levels were evaluated in natural and drinking water in Bangladesh. A highly sensitive immunosorbent assay was used to detect microcystins (MCs). Cyanobacteria were found in 22 of 23 samples and the dominant species were Microcystis aeruginosa, followed by Microcystisflosaquae, Anabeana crassa and Aphanizomenon flosaquae. Cyanobacterial abundance varied from 39 to 1315 x 10(3) cells mL(-1) in natural water and 31 to 49 x 10(3) cells mL(-1) in tap water. MC concentrations were 25-82300 pg mL(-1) with the highest value measured in the fish research pond, followed by Ishakha Lake. In tap water, MC concentrations ranged from 30-32 pg mL(-1). The correlation between nitrate-nitrogen (NO3-N) concentration and cyanobacterial cell abundance was R2 = 0.62 while that between cyanobacterial abundance and MC concentration was R2 = 0.98. The increased NO3-N from fish feed, organic manure, poultry and dairy farm waste and fertilizer from agricultural land eutrophicated the water bodies and triggered cyanobacterial bloom formation. The increased amount of cyanobacteria produced MCs, subsequently reducing the water quality. PMID:26364354

  1. Symbiotic nitrogen fixation in an arid ecosystem measured by sup 15 N natural abundance

    SciTech Connect

    Johnson, G.V. )

    1990-05-01

    Plants dependent on nitrogen fixation have an {sup 15}N abundance similar to the atmosphere, while non-nitrogen fixing plants usually are enriched in {sup 15}N and are similar to soil nitrogen values. The natural abundance of {sup 15}N in leaf tissues and soils was determined to evaluate symbiotic nitrogen fixation by several legumes and actinorhizal species in the Sevilleta Long-term Ecological Research area in central New Mexico. Comparison of {delta}{sup 15}N values for the legume Prosopis glandulosa (mesquite) to adjacent Atriplex canascens (fourwing saltbush) indicated that P. glandulosa obtained 66% of its nitrogen by fixation. The legume Hoffmanseggia jamesii was found to be utilizing soil nitrogen. The {delta}{sup 15}N values for the actinorhizal plants, Elaeagnus angustifolia and Cercocarpus montanus, while below values for soil nitrogen, did not differ from associated non-fixing plants.

  2. Natural abundances of carbon isotopes in acetate from a coastal marine sediment

    NASA Technical Reports Server (NTRS)

    Blair, N. E.; Martens, C. S.; Des Marais, D. J.

    1987-01-01

    Measurements of the natural abundances of carbon isotopes were made in acetate samples isolated from the anoxic marine sediment of Cape Lookout Bight, North Carolina. The typical value of the total acetate carbon isotope ratio (delta 13C) was -16.1 +/- 0.2 per mil. The methyl and carboxyl groups were determined to be -26.4 +/- 0.3 and -6.0 +/- 0.3 per mil, respectively, for one sample. The isotopic composition of the acetate is thought to have resulted from isotopic discriminations that occurred during the cycling of that molecule. Measurements of this type, which have not been made previously in the natural environment, may provide information about the dominant microbial pathways in anoxic sediments as well as the processes that influence the carbon isotopic composition of biogenic methane from many sources.

  3. High-resolution magic-angle spinning (13)C spectroscopy of brain tissue at natural abundance.

    PubMed

    Yang, Yongxia; Chen, Lei; Gao, Hongchang; Zeng, Danlin; Yue, Yong; Liu, Maili; Lei, Hao; Deng, Feng; Ye, Chaohui

    2006-03-01

    High-resolution magic-angle spinning (MAS) (1)H and (13)C magnetic resonance spectroscopy (MRS) has recently been applied to study the metabolism in intact biological tissue samples. Because of the low natural abundance and the low gyromagnetic ratio of the (13)C nuclei, signal enhancement techniques such as cross-polarization (CP) and distortionless enhancement by polarization transfer (DEPT) are often employed in MAS (13)C MRS to improve the detection sensitivity. In this study, several sensitivity enhancement techniques commonly used in liquid- and solid-state NMR, including CP, DEPT and nuclear Overhauser enhancement (NOE), were combined with MAS to acquire high-resolution (13)C spectra on intact rat brain tissue at natural abundance, and were compared for their performances. The results showed that different signal enhancement techniques are sensitive to different classes of molecules/metabolites, depending on their molecular weights and mobility. DEPT was found to enhance the signals of low-molecular weight metabolites exclusively, while the signals of lipids, which often are associated with membranes and have relatively lower mobility, were highly sensitive to CP enhancement. PMID:16477685

  4. Changes in protein abundance are observed in bacterial isolates from a natural host

    PubMed Central

    Rees, Megan A.; Stinear, Timothy P.; Goode, Robert J. A.; Coppel, Ross L.; Smith, Alexander I.; Kleifeld, Oded

    2015-01-01

    Bacterial proteomic studies frequently use strains cultured in synthetic liquid media over many generations. It is uncertain whether bacterial proteins expressed under these conditions will be the same as the repertoire found in natural environments, or when bacteria are infecting a host organism. Thus, genomic and proteomic characterization of bacteria derived from the host environment in comparison to reference strains grown in the lab, should aid understanding of pathogenesis. Isolates of Corynebacterium pseudotuberculosis were obtained from the lymph nodes of three naturally infected sheep and compared to a laboratory reference strain using bottom-up proteomics, after whole genome sequencing of each of the field isolates. These comparisons were performed following growth in liquid media that allowed us to reach the required protein amount for proteomic analysis. Over 1350 proteins were identified in the isolated strains, from which unique proteome features were revealed. Several of the identified proteins demonstrated a significant abundance difference in the field isolates compared to the reference strain even though there were no obvious differences in the DNA sequence of the corresponding gene or in nearby non-coding DNA. Higher abundance in the field isolates was observed for proteins related to hypoxia and nutrient deficiency responses as well as to thiopeptide biosynthesis. PMID:26528441

  5. Easing the natural gas crisis: Reducing natural gas prices through increased deployment of renewable energy and energy efficiency

    SciTech Connect

    Wiser, Ryan; Bolinger, Mark; St. Clair, Matt

    2004-12-21

    Heightened natural gas prices have emerged as a key energy-policy challenge for at least the early part of the 21st century. With the recent run-up in gas prices and the expected continuation of volatile and high prices in the near future, a growing number of voices are calling for increased diversification of energy supplies. Proponents of renewable energy and energy efficiency identify these clean energy sources as an important part of the solution. Increased deployment of renewable energy (RE) and energy efficiency (EE) can hedge natural gas price risk in more than one way, but this paper touches on just one potential benefit: displacement of gas-fired electricity generation, which reduces natural gas demand and thus puts downward pressure on gas prices. Many recent modeling studies of increased RE and EE deployment have demonstrated that this ''secondary'' effect of lowering natural gas prices could be significant; as a result, this effect is increasingly cited as justification for policies promoting RE and EE. This paper summarizes recent studies that have evaluated the gas-price-reduction effect of RE and EE deployment, analyzes the results of these studies in light of economic theory and other research, reviews the reasonableness of the effect as portrayed in modeling studies, and develops a simple tool that can be used to evaluate the impact of RE and EE on gas prices without relying on a complex national energy model. Key findings are summarized.

  6. Differences in the fractional abundances of carbohydrates of natural and recombinant human tissue factor

    PubMed Central

    Krudysz-Amblo, Jolanta; Jennings, Mark E; Matthews, Dwight E; Mann, Kenneth G; Butenas, Saulius

    2011-01-01

    Tissue factor (TF) is a single polypeptide integral membrane glycoprotein composed of 263 residues and is essential to life in its role as the initiator of blood coagulation. Objective Previously we have shown that the activity of the natural placental TF (pTF) and the recombinant TF (rTF) from Sf9 insect cells is different (Krudysz-Amblo, J. et al(2010) J. Biol. Chem. 285, 3371–3382). In this study, using mass spectrometry, we show by quantitative analysis that the extent of glycosylation varies on each protein. Results Fractional abundance, of each glycan composition at each of the three glycosylation sites, reveals the most pronounced difference to be at asparagine (Asn) 11. This residue is located in the region of extensive TFfactor VIIa (FVIIa) interaction. Carbohydrate fractional abundance at Asn11 revealed that glycosylation in the natural placental TF is much more prevalent (~76%) than in the recombinant protein (~20%). The extent of glycosylation on Asn124 and Asn137 is similar in the two proteins, despite the pronounced differences in the carbohydrate composition. Additionally, 77% of rTF exists as TF des-1, 2 (missing the first two amino acids from the N-terminus). In contrast, only 31% of pTF is found in the des-1, 2 form. Conclusion These observations may attribute to the difference in the ability of TF-FVIIa complex to activate factor X (FX). Structural and functional comparison of the recombinant and natural protein advances our understanding and knowledge on the biological activity of TF. PMID:21172408

  7. Abundance and phenology patterns of two pond-breeding salamanders determine species interactions in natural populations.

    PubMed

    Anderson, Thomas L; Hocking, Daniel J; Conner, Christopher A; Earl, Julia E; Harper, Elizabeth B; Osbourn, Michael S; Peterman, William E; Rittenhouse, Tracy A G; Semlitsch, Raymond D

    2015-03-01

    Phenology often determines the outcome of interspecific interactions, where early-arriving species often dominate interactions over those arriving later. The effects of phenology on species interactions are especially pronounced in aquatic systems, but the evidence is largely derived from experimental studies. We examined whether differences in breeding phenology between two pond-breeding salamanders (Ambystoma annulatum and A. maculatum) affected metamorph recruitment and demographic traits within natural populations, with the expectation that the fall-breeding A. annulatum would negatively affect the spring-breeding A. maculatum. We monitored populations of each species at five ponds over 4 years using drift fences. Metamorph abundance and survival of A. annulatum were affected by intra- and interspecific processes, whereas metamorph size and date of emigration were primarily influenced by intraspecific effects. Metamorph abundance, snout-vent length, date of emigration and survival for A. maculatum were all predicted by combinations of intra- and interspecific effects, but often showed negative relationships with A. annulatum metamorph traits and abundance. Size and date of metamorphosis were strongly correlated within each species, but in opposite patterns (negative for A. annulatum and positive for A. maculatum), suggesting that the two species use alternative strategies to enhance terrestrial survival and that these factors may influence their interactions. Our results match predictions from experimental studies that suggest recruitment is influenced by intra- and interspecific processes which are determined by phenological differences between species. Incorporating spatiotemporal variability when modeling population dynamics is necessary to understand the importance of phenology in species interactions, especially as shifts in phenology occur under climate change. PMID:25413866

  8. Toward the renewables - A natural gas/solar energy transition strategy

    NASA Technical Reports Server (NTRS)

    Hanson, J. A.; Escher, W. J. D.

    1979-01-01

    The inevitability of an energy transition from today's non-renewable fossil base toward a renewable energy base is considered from the viewpoint of the need for a national transition strategy. Then, one such strategy is offered. Its technological building blocks are described in terms of both energy use and energy supply. The strategy itself is then sketched at four points in its implementation; (1) initiation, (2) early transition, (3) late transition, and (4) completion. The transition is assumed to evolve from a heavily natural gas-dependent energy economy. It then proceeds through its transition toward a balanced, hybrid energy system consisting of both centralized and dispersed energy supply technologies supplying hydrogen and electricity from solar energy. Related institutional, environmental and economic factors are examined briefly.

  9. On the nature of lithium-rich giant stars. Constraints from beryllium abundances

    NASA Astrophysics Data System (ADS)

    Melo, C. H. F.; de Laverny, P.; Santos, N. C.; Israelian, G.; Randich, S.; Do Nascimento, J. D., Jr.; de Medeiros, J. R.

    2005-08-01

    We have derived beryllium abundances for 7 Li-rich giant (A(Li) > 1.5) stars and 10 other Li-normal giants with the aim of investigating the origin of the lithium in the Li-rich giants. In particular, we test the predictions of the engulfment scenario proposed by Siess & Livio (1999, MNRAS, 308, 1133), where the engulfment of a brown dwarf or one or more giant planets would lead to simultaneous enrichment of 7Li and 9Be. We show that regardless of their nature, none of the stars studied in this paper were found to have detectable beryllium. Using simple dilution arguments we show that engulfment of an external object as the sole source of Li enrichment is ruled out by the Li and Be abundance data. The present results favor the idea that Li has been produced in the interior of the stars by a Cameron-Fowler process and brought up to the surface by an extra mixing mechanism.

  10. Distribution and Abundance of Insertion Sequences among Natural Isolates of Escherichia coli

    PubMed Central

    Sawyer, Stanley A.; Dykhuizen, Daniel E.; DuBose, Robert F.; Green, Louis; Mutangadura-Mhlanga, T.; Wolczyk, David F.; Hartl, Daniel L.

    1987-01-01

    A reference collection of 71 natural isolates of Escherichia coli (the ECOR collection) has been studied with respect to the distribution and abundance of transposable insertion sequences using DNA hybridization. The data include 1173 occurrences of six unrelated insertion sequences (IS 1, IS2, IS3, IS4, IS5 and IS 30). The number of insertion elements per strain, and the sizes of DNA restriction fragments containing them, is highly variable and can be used to discriminate even among closely related strains. The occurrence and abundance of pairs of unrelated insertion sequences are apparently statistically independent, but significant correlations result from stratifications in the reference collection. However, there is a highly significant positive association among the insertion sequences considered in the aggregate. Nine branching process models, which differ in assumptions regarding the regulation of transposition and the effect of copy number on fitness, have been evaluated with regard to their fit of the observed distributions. No single model fits all copy number distributions. The best models incorporate no regulation of transposition and a moderate to strong decrease in fitness with increasing copy number for IS1 and IS5, strong regulation of transposition and a negligible to weak decrease in fitness with increasing copy number for IS3, and less than strong regulation of transposition for IS2, IS 4 and IS30. PMID:3030884

  11. Investigating microbial carbon cycling using natural abundance isotope analysis of PLFA

    NASA Astrophysics Data System (ADS)

    Slater, G. G.; Brady, A.; Cowie, B.

    2008-12-01

    Understanding microbial carbon sources and cycling is fundamental to our conceptualization of microbial ecosystems and their role in biogeochemical cycling in natural systems. Achieving this understanding requires application of a wide range of approaches. Natural abundance isotope analysis of individual compounds, particularly cellular components such as Phospholipids Fatty Acids (PLFA) can provide insights into the carbon sources and metabolic activities of the in situ microbial community from environmental samples. This is primarily because specific PLFA can be well resolved by gas chromatography even from complex matrices where confounding biological/organic compound abound. These PLFA can then be attributed to the viable microbial community, in some cases to specific components of this community and due to characteristic biosynthetic fractionations of stable isotope ratios, δ13C analysis of PLFA can: differentiate isotopically distinct primary carbon sources of heterotrophic communities; identify isotopic patterns characteristic of autotrophic versus heterotrophic processes; and elucidate microbial biosynthetic pathways. In cases where there δ13C cannot provide resolution of carbon sources, new approaches in Δ14C of PLFA can be applied. The vast range in Δ14C of ancient and modern carbon provides an easily traceable signal that can differentiate uptake and utilization of these carbon sources. This is particularly useful in cases such as contaminated sites where petroleum based contamination has occurred, or in natural systems where microbial communities may be utilizing geologic versus recently photosynthetically fixed carbon. This talk will present several examples demonstrating the utility of this approach.

  12. Natural abundant (17) O NMR in a 1.5-T Halbach magnet.

    PubMed

    Sørensen, Morten K; Bakharev, Oleg N; Jensen, Ole; Nielsen, Niels Chr

    2016-06-01

    We present mobile, low-field (17) O NMR as a means for monitoring oxygen in liquids. Whereas oxygen is one of the most important elements, oxygen NMR is limited by a poor sensitivity related to low natural abundance and gyro-magnetic ratio of the NMR active (17) O isotope. Here, we demonstrate (17) O NMR detection at a Larmor frequency of 8.74 MHz in a 1.5-T Halbach neodymium magnet with a home-built digital NMR instrument suitable for large-scale production and in-line monitoring applications. The proposed (17) O NMR sensor may be applied for direct, noninvasive measurements of water content in, for example, oil, manure, or food in automated quality or process control. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25641664

  13. Natural abundance 14N and 15N solid-state NMR of pharmaceuticals and their polymorphs

    DOE PAGESBeta

    Veinberg, Stanislav L.; Johnston, Karen E.; Jaroszewicz, Michael J.; Kispal, Brianna M.; Mireault, Christopher R.; Kobayashi, Takeshi; Pruski, Marek; Schurko, Robert W.

    2016-06-08

    14N ultra-wideline (UW), 1H{15N} indirectly-detected HETCOR (idHETCOR) and 15N dynamic nuclear polarization (DNP) solid-state NMR (SSNMR) experiments, in combination with plane-wave density functional theory (DFT) calculations of 14N EFG tensors, were utilized to characterize a series of nitrogen-containing active pharmaceutical ingredients (APIs), including HCl salts of scopolamine, alprenolol, isoprenaline, acebutolol, dibucaine, nicardipine, and ranitidine. Here, a case study applying these methods for the differentiation of polymorphs of bupivacaine HCl is also presented. All experiments were conducted upon samples with naturally-abundant nitrogen isotopes. For most of the APIs, it was possible to acquire frequency-stepped UW 14N SSNMR spectra of stationarymore » samples, which display powder patterns corresponding to pseudo-tetrahedral (i.e., RR'R"NH+ and RR'NH2+) or other (i.e., RNH2 and RNO2) nitrogen environments.« less

  14. In Vivo Natural-Abundance 13C Nuclear Magnetic Resonance Studies of Living Ectomycorrhizal Fungi 1

    PubMed Central

    Martin, Francis; Canet, Daniel; Marchal, Jean-Pierre; Brondeau, Jean

    1984-01-01

    Natural-abundance 13C nuclear magnetic resonance spectroscopy has been used to study intact mycelia of the ectomycorrhizal fungi Cenococcum graniforme (Ascomycetes) and Hebeloma crustuliniforme (Basidiomycetes). A number of sharp resonances are observed in living fungi. These signals primarily arise from fatty acyl chains and carbohydrate nuclei. The spectra are interpreted in terms of relative concentrations of the major fatty acids present in the fungal triglycerides. The small line width of fatty acids (mainly oleic, linoleic, and palmitic acids) resonances and spin-lattice relaxation time are indicative of fast rotational reorientations and are consequently thought to arise from fatty acyl chains in fat droplets. We were able to locate the site of lipids accumulation within mycelia using light microscopy and histological staining. Many lipid droplets were observed in mycelia of both species. These results suggest that fatty acids droplets could be involved in carbon storage and metabolism from ectomycorrhizal fungi. PMID:16663561

  15. HCNMBC - A pulse sequence for H-(C)-N Multiple Bond Correlations at natural isotopic abundance

    NASA Astrophysics Data System (ADS)

    Cheatham, Steve; Gierth, Peter; Bermel, Wolfgang; Kupče, Ēriks

    2014-10-01

    We propose a pulse sequence, HCNMBC for multiple-bond H-(C)-N correlation experiments via one-bond 1J(C,H) and one- or multiple bond nJ(N,C) coupling constants (typically n = 1-3) at the natural isotopic abundance. A new adiabatic refocussing sequence is introduced to provide accurate and robust refocussing of both chemical shift and J-evolution over wide ranges of C-13 and N-15 frequencies. It is demonstrated that the proposed pulse sequence provides high quality spectra even for sub-milligram samples. We show that when a 1.7 mm cryoprobe is available as little as 10 μg of glycine in D2O is sufficient to obtain the HCNMBC spectrum in ca. 12 h. The preliminary results indicate that the pulse sequence has a great potential in the structure determination of nitrogen heterocycles especially in cases where synthesis produces regioisomers.

  16. On the nature of sn stars. I. A detailed abundance study

    NASA Astrophysics Data System (ADS)

    Saffe, C.; Levato, H.

    2014-02-01

    The sn stars were first discoved by Abt & Levato when studying the spectral types in different open clusters. These stars present sharp Balmer lines, sharp metallic lines (C II, Si II, Ca II, Ti II, Fe II), and broad coreless He I lines. Some of the sn stars seem to be related to CP stars. Initially Abt & Levato proposed a shell-like nature to explain the sn stars, although this scenario was subsequently questioned. There is no general agreement about their origin. We aim to derive abundances for a sample of 9 stars, including sn and non-sn stars, to determine the possible relation between sn and CP stars and compare their chemical abundances. That most sn stars belong to open clusters allows us to search for a possible relation with fundamental parameters, including the age and rotation. We also study the possible contribution of different effects to the broad He I lines observed in these stars, such as Stark broadening and the possible He-stratification. Effective temperature and gravity were estimated by Strömgren photometry and then refined by requiring ionization and excitation equilibrium of Fe lines. We derived the abundances by fitting the observed spectra with synthetic spectra using an iterative procedure with the SYNTHE and ATLAS9 codes. We derived metallic abundances of 23 different chemical elements for 9 stars and obtained low projected rotational velocities for the sn stars in our sample (vsini up to 69 km s-1). We also compared 5 stars that belong to the same cluster (NGC 6475) and show that the sn characteristics appear in the 3 stars with the lower rotational velocity. However, the apparent preference of sn stars for objects with the lower vsini values should be taken with caution due to the small number of objects studied here. We analysed the photospheric chemical composition of sn stars and show that approximately ~40% of them display chemical peculiarities (such as He-weak and HgMn stars) within a range of temperature of 10 300 K-14 500 K

  17. Archaeal community diversity and abundance changes along a natural salinity gradient in estuarine sediments

    PubMed Central

    Webster, Gordon; O'Sullivan, Louise A.; Meng, Yiyu; Williams, Angharad S.; Sass, Andrea M.; Watkins, Andrew J.; Parkes, R. John; Weightman, Andrew J.

    2014-01-01

    Archaea are widespread in marine sediments, but their occurrence and relationship with natural salinity gradients in estuarine sediments is not well understood. This study investigated the abundance and diversity of Archaea in sediments at three sites [Brightlingsea (BR), Alresford (AR) and Hythe (HY)] along the Colne Estuary, using quantitative real-time PCR (qPCR) of 16S rRNA genes, DNA hybridization, Archaea 16S rRNA and mcrA gene phylogenetic analyses. Total archaeal 16S rRNA abundance in sediments were higher in the low-salinity brackish sediments from HY (2–8 × 107 16S rRNA gene copies cm−3) than the high-salinity marine sites from BR and AR (2 × 104–2 × 107 and 4 × 106–2 × 107 16S rRNA gene copies cm−3, respectively), although as a proportion of the total prokaryotes Archaea were higher at BR than at AR or HY. Phylogenetic analysis showed that members of the ‘Bathyarchaeota’ (MCG), Thaumarchaeota and methanogenic Euryarchaeota were the dominant groups of Archaea. The composition of Thaumarchaeota varied with salinity, as only ‘marine’ group I.1a was present in marine sediments (BR). Methanogen 16S rRNA genes from low-salinity sediments at HY were dominated by acetotrophic Methanosaeta and putatively hydrogentrophic Methanomicrobiales, whereas the marine site (BR) was dominated by mcrA genes belonging to methylotrophic Methanococcoides, versatile Methanosarcina and methanotrophic ANME-2a. Overall, the results indicate that salinity and associated factors play a role in controlling diversity and distribution of Archaea in estuarine sediments. PMID:25764553

  18. Regional patterns of 15N natural abundance in forest ecosystems along a large transect in eastern China

    NASA Astrophysics Data System (ADS)

    Sheng, Wenping; Yu, Guirui; Fang, Huajun; Liu, Yingchun; Wang, Qiufeng; Chen, Zhi; Zhang, Li

    2014-02-01

    The regional determining factors underlying inter- and intra-site variation of 15N natural abundance in foliage, O horizon and mineral soil were investigated in eastern China.15N natural abundance values for these forest ecosystems were in the middle of the range of values previously found for global forest ecosystems. In contrast to commonly reported global patterns, temperate forest ecosystems were significantly more15N-enriched than tropical forest ecosystems, and foliage δ15N was negatively correlated with increasing mean annual temperature and net soil N mineralisation in eastern China. Tight N cycling in forest ecosystems and the use of atmospheric N deposition by trees might underlie the δ15N distribution patterns in eastern China. The existence of mycorrhizal fungi and root distribution profiles in the soil may also influence the15N natural abundance patterns in forest ecosystems of eastern China.

  19. Natural abundance nitrogen-15 nuclear magnetic resonance spectral studies on selected donors

    NASA Astrophysics Data System (ADS)

    Someswara Rao, N.; Babu Rao, G.; Murthy, B. N.; Das, M. Maria; Prabhakar, T.; Lalitha, M.

    2002-10-01

    The natural abundance 15N-NMR chemical shifts of selected aliphatic amines, 2-substituted pyridine type compounds, bialicyclic tertiary amines have been measured as a function of the nature of the solvent. In the case of cyclic aliphatic amines, like piperidine, morpholine, piperazine, thiomorpholine, the nitrogen is more shielded in concentrated solution compared to that in dilute solution whereas in the hydrogen bonding and protonating solvents there is a prominent deshielding. 2-Substituted pyridines studied can be further divided into four sub groups. The site of hydrogen bonding and protonation in 2-amino, 2-hydroxy and 2-mercapto pyridines have been conclusively proved from the 15N-NMR chemical shifts and the well-known tautomeric forms of the above compounds. Similarly in the case of 2-(2-thienyl)pyridine and 2-(3-thienyl)pyridine, the site of donation has been proved as the nitrogen of the pyridine ring in both the compounds. In a similar manner, the site of hydrogen bonding and protonation in two individual compounds 2-anilinopyridine and 2-(2-pyridyl)benzimidazole have also been established. Among the bialicyclic amines, 1,2-diazabicyclo[2.2.2]octane (DABCO) behaved differently from the other two compounds. In both 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), it was possible to show that N 1-nitrogen in both the compounds is the site of donation. The effect of the second donor site on the 15N-NMR chemical shift, the site of donation in the selected compounds and some typical compounds reported in literature have been presented and discussed.

  20. Characterization of Stratum Corneum Molecular Dynamics by Natural-Abundance 13C Solid-State NMR

    PubMed Central

    Bouwstra, Joke A.; Sparr, Emma; Topgaard, Daniel

    2013-01-01

    Despite the enormous potential for pharmaceutical applications, there is still a lack of understanding of the molecular details that can contribute to increased permeability of the stratum corneum (SC). To investigate the influence of hydration and heating on the SC, we record the natural-abundance 13C signal of SC using polarization transfer solid-state NMR methods. Resonance lines from all major SC components are assigned. Comparison of the signal intensities obtained with the INEPT and CP pulse sequences gives information on the molecular dynamics of SC components. The majority of the lipids are rigid at 32°C, and those lipids co-exist with a small pool of mobile lipids. The ratio between mobile and rigid lipids increases with hydration. An abrupt change of keratin filament dynamics occurs at RH = 80–85%, from completely rigid to a structure with rigid backbone and mobile protruding terminals. Heating has a strong effect on the lipid mobility, but only a weak influence on the keratin filaments. The results provide novel molecular insight into how the SC constituents are affected by hydration and heating, and improve the understanding of enhanced SC permeability, which is associated with elevated temperatures and SC hydration. PMID:23626744

  1. Natural abundance 17O nuclear magnetic resonance and computational modeling studies of lithium based liquid electrolytes

    NASA Astrophysics Data System (ADS)

    Deng, Xuchu; Hu, Mary Y.; Wei, Xiaoliang; Wang, Wei; Chen, Zhong; Liu, Jun; Hu, Jian Zhi

    2015-07-01

    Natural abundance 17O NMR measurements were conducted on electrolyte solutions consisting of Li[CF3SO2NSO2CF3] (LiTFSI) dissolved in the solvents of ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), and their mixtures at various concentrations. It was observed that 17O chemical shifts of solvent molecules change with the concentration of LiTFSI. The chemical shift displacements of carbonyl oxygen are evidently greater than those of ethereal oxygen, strongly indicating that Li+ ion is coordinated with carbonyl oxygen rather than ethereal oxygen. To understand the detailed molecular interaction, computational modeling of 17O chemical shifts was carried out on proposed solvation structures. By comparing the predicted chemical shifts with the experimental values, it is found that a Li+ ion is coordinated with four double bond oxygen atoms from EC, PC, EMC and TFSI- anion. In the case of excessive amount of solvents of EC, PC and EMC the Li+ coordinated solvent molecules are undergoing quick exchange with bulk solvent molecules, resulting in average 17O chemical shifts. Several kinds of solvation structures are identified, where the proportion of each structure in the liquid electrolytes investigated depends on the concentration of LiTFSI.

  2. Probing surface hydrogen bonding and dynamics by natural abundance, multidimensional, 17O DNP-NMR spectroscopy

    DOE PAGESBeta

    Perras, Frederic A.; Chaudhary, Umesh; Slowing, Igor I.; Pruski, Marek

    2016-05-06

    Dynamic nuclear polarization (DNP)-enhanced solid-state nuclear magnetic resonance (SSNMR) spectroscopy is increasingly being used as a tool for the atomic-level characterization of surface sites. DNP surface-enhanced SSNMR spectroscopy of materials has, however, been limited to studying relatively receptive nuclei, and the particularly rare 17O nuclide, which is of great interest for materials science, has not been utilized. We demonstrate that advanced 17O SSNMR experiments can be performed on surface species at natural isotopic abundance using DNP. We use 17O DNP surface-enhanced 2D SSNMR to measure 17O{1H} HETCOR spectra as well as dipolar oscillations on a series of thermally treatedmore » mesoporous silica nanoparticle samples having different pore diameters. These experiments allow for a nonintrusive and unambiguous characterization of hydrogen bonding and dynamics at the surface of the material; no other single experiment can give such details about the interactions at the surface. Lastly, our data show that, upon drying, strongly hydrogen-bonded surface silanols, whose motions are greatly restricted by the interaction when compared to lone silanols, are selectively dehydroxylated.« less

  3. Natural Abundance 17O Nuclear Magnetic Resonance and Computational Modeling Studies of Lithium Based Liquid Electrolytes

    SciTech Connect

    Deng, Xuchu; Hu, Mary Y.; Wei, Xiaoliang; Wang, Wei; Chen, Zhong; Liu, Jun; Hu, Jian Z.

    2015-07-01

    Natural abundance 17O NMR measurements were conducted on electrolyte solutions consisting of Li[CF3SO2NSO2CF3] (LiTFSI) dissolved in the solvents of ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), and their mixtures at various concentrations. It was observed that 17O chemical shifts of solvent molecules change with the concentration of LiTFSI. The chemical shift displacements of carbonyl oxygen are evidently greater than those of ethereal oxygen, strongly indicating that Li+ ion is coordinated with carbonyl oxygen rather than ethereal oxygen. To understand the detailed molecular interaction, computational modeling of 17O chemical shifts was carried out on proposed solvation structures. By comparing the predicted chemical shifts with the experimental values, it is found that a Li+ ion is coordinated with four double bond oxygen atoms from EC, PC, EMC and TFSI- anion. In the case of excessive amount of solvents of EC, PC and EMC the Li+ coordinated solvent molecules are undergoing quick exchange with bulk solvent molecules, resulting in average 17O chemical shifts. Several kinds of solvation structures are identified, where the proportion of each structure in the liquid electrolytes investigated depends on the concentration of LiTFSI.

  4. Natural abundance deuterium and 18-oxygen effects on the precision of the doubly labeled water method

    NASA Technical Reports Server (NTRS)

    Horvitz, M. A.; Schoeller, D. A.

    2001-01-01

    The doubly labeled water method for measuring total energy expenditure is subject to error from natural variations in the background 2H and 18O in body water. There is disagreement as to whether the variations in background abundances of the two stable isotopes covary and what relative doses of 2H and 18O minimize the impact of variation on the precision of the method. We have performed two studies to investigate the amount and covariance of the background variations. These were a study of urine collected weekly from eight subjects who remained in the Madison, WI locale for 6 wk and frequent urine samples from 14 subjects during round-trip travel to a locale > or = 500 miles from Madison, WI. Background variation in excess of analytical error was detected in six of the eight nontravelers, and covariance was demonstrated in four subjects. Background variation was detected in all 14 travelers, and covariance was demonstrated in 11 subjects. The median slopes of the regression lines of delta2H vs. delta18O were 6 and 7, respectively. Modeling indicated that 2H and 18O doses yielding a 6:1 ratio of final enrichments should minimize this error introduced to the doubly labeled water method.

  5. Relation of desert pupfish abundance to selected environmental variables in natural and manmade habitats in the Salton Sea basin

    USGS Publications Warehouse

    Martin, B.A.; Saiki, M.K.

    2005-01-01

    We assessed the relation between abundance of desert pupfish, Cyprinodon macularius, and selected biological and physicochemical variables in natural and manmade habitats within the Salton Sea Basin. Field sampling in a natural tributary, Salt Creek, and three agricultural drains captured eight species including pupfish (1.1% of the total catch), the only native species encountered. According to Bray-Curtis resemblance functions, fish species assemblages differed mostly between Salt Creek and the drains (i.e., the three drains had relatively similar species assemblages). Pupfish numbers and environmental variables varied among sites and sample periods. Canonical correlation showed that pupfish abundance was positively correlated with abundance of western mosquitofish, Gambusia affinis, and negatively correlated with abundance of porthole livebearers, Poeciliopsis gracilis, tilapias (Sarotherodon mossambica and Tilapia zillii), longjaw mudsuckers, Gillichthys mirabilis, and mollies (Poecilia latipinnaandPoecilia mexicana). In addition, pupfish abundance was positively correlated with cover, pH, and salinity, and negatively correlated with sediment factor (a measure of sediment grain size) and dissolved oxygen. Pupfish abundance was generally highest in habitats where water quality extremes (especially high pH and salinity, and low dissolved oxygen) seemingly limited the occurrence of nonnative fishes. This study also documented evidence of predation by mudsuckers on pupfish. These findings support the contention of many resource managers that pupfish populations are adversely influenced by ecological interactions with nonnative fishes. ?? Springer 2005.

  6. Elevated Bacterial Abundance in Laboratory-Grown and Naturally Occurring Frost Flowers Under Late Winter Conditions

    NASA Astrophysics Data System (ADS)

    Bowman, J. S.; Deming, J. W.

    2009-12-01

    Sea ice has been identified as an important microbial habitat, with bacteria and other microbes concentrated in the brine inclusions between ice crystals. Frost flowers, thought to draw brine from underlying sea ice, have not been characterized from a microbial standpoint. To test whether frost flowers serve as an upward vector of bacteria contained within sea ice brines we grew frost flowers in a freezer laboratory (air temperature of -21°C) from saline water spiked with the mesophilic (and thus passive under experimental conditions) bacterium Halomonas pacifica. Salinity of melted samples was measured and bacterial abundance determined by epifluorescent microscopy. Bacterial counts scaled to ice-melt volume averaged 2.82 x 106 ml-1 for frost flowers, compared to 9.47 x 105 ml-1 for underlying ice (3 x higher). Bacterial counts also correlated significantly with salinity (maximum value of 62.5 psu) for frost flowers, brine skim, and ice (df = 17, r = 0.59, p < 0.0001). Segregation coefficients were calculated to describe the efficiency of transport of both cells and salt from the starting solution into frost flowers. From these coefficients an enrichment index was calculated to test for bacterial concentration into frost flowers at a different rate than salt. Analysis with a Student’s T-test (df = 24, t = 0.306, p = .76) indicated that cells and salt were not transported into frost flowers with a significantly different efficiency. To test these findings in the field we then collected frost flowers (and related samples) from new sea ice near Barrow, Alaska in April 2009. Bacterial counts were significantly elevated (again, a 3-fold increase) in natural frost flowers (mean = 2.73 x 105 ml-1) compared to underlying sea ice (mean = 8.46 x 104 cells ml-1). For all field samples collected (frost flowers, underlying brine skim and sea ice, as well as snow), bacterial abundance correlated significantly with salinity (maximum value 124 psu, df = 40, r = 0.60, p < 0

  7. The Determination of the Natural Abundance of the Isotopes of Chlorine: An Introductory Experiment in Mass Spectrometry.

    ERIC Educational Resources Information Center

    O'Malley, Rebecca M.

    1982-01-01

    Describes a laboratory experiment which introduces basic principles and experimental techniques of mass spectrometry for fourth year undergraduate (B.Sc.) students. Laboratory procedures, background information, and discussion of results are provided for the experiment in which the natural isotopic abundance of chlorine is determined. (Author/JN)

  8. Seasonal variation in natural abundance of 2H and 18O in urine samples from rural Nigeria

    PubMed Central

    Dugas, Lara R.; Brieger, William; Tayo, Bamidele O.; Alabi, Tunrayo; Schoeller, Dale A.; Luke, Amy

    2015-01-01

    The doubly labeled water (DLW) method is used to measure free-living energy expenditure in humans. Inherent to this technique is the assumption that natural abundances of stable isotopes 2H and 18O in body water remain constant over the course of the measurement period and after elimination of the loading dose of DLW will return to the same predose level. To determine variability in the natural abundances of 2H and 18O in humans living in a region with seasonal shifts in rain patterns and sources of drinking water, over the course of 12 mo we collected weekly urine samples from four individuals living in southwest Nigeria as well as samples of their drinking water. From ongoing regional studies of hypertension, obesity, and energy expenditure, we estimated average water turnover rate, urine volumes, and sodium and potassium excretion. Results suggest that 2H and 18O in urine, mean concentrations of urinary sodium and potassium, urine volume, and total body turnover differed significantly from dry to rainy season. Additionally, seasonal weather variables (mean monthly maximum temperatures, total monthly rainfall, and minimum relative humidity) were all significantly associated with natural abundances in urine. No seasonal difference was observed in drinking water samples. Findings suggest that natural abundances in urine may not remain constant as assumed, and studies incorporating DLW measurements across the transition of seasons should interpret results with caution unless appropriate doses of the tracers are used. PMID:25977450

  9. Natural abundance deuterium nuclear magnetic resonance spectroscopy: Study of the biosynthesis of monoterpenes

    SciTech Connect

    Leopold, M.F.

    1990-01-01

    Deuterium NMR spectroscopy at natural abundance (D NMR-na) is a new technique for exploring the biosynthesis of small molecules such as monoterpenes. The analysis of relative site-specific deuterium integration values is an effective means of measuring isotope effects, and examining the regio- and stereochemistry of biosynthetic reactions. The deuterium integration values of linalyl acetate and limonene isolated from the same source were consistent and showed that proton abstraction from the postulated {alpha}-terpinyl cation intermediate to form limonene is regioselective from the methyl derived from the Cs methyl of the precursor, geranyl diphosphate. This regiochemistry was observed in limonene samples from different sources and the measured primary kinetic isotope effect ranged from 0.25 to in excess of 100 (no deuterium was removed within experimental error). Various {alpha}- and {beta}-pinene samples were isolated and D NMR-na analysis showed evidence of isotopically sensitive partitioning of the pinylcation in the formation of these products. This spectral analysis supported published radiolabeling studies but did not require synthesis of substrates or enzyme purification. The formation of 3-carene occurs without isomerization of the double bond which was previously postulated. The olefinic deuterium of the bicyclic compound was traced to the depleted deuterium at C{sub 2} of isopentyl diphosphate by D NMR-na data and this supported unpublished radiolabeling studies. Study of irregular monoterpenes, chrysanthemyl acetate and lyratyl acetate, showed partitioning of dimethylallyl diphosphate (DMAPP) by chrysanthemyl cyclase. The {alpha}-secondary kinetic isotope effect of 1.06-1.12, obtained from relative deuterium integration values, suggested that S{sub N}1 ionization of one molecule of DMAPP is the first step in the condensation reaction.

  10. A robust method for ammonium nitrogen isotopic analysis in freshwater and seawater at natural abundance levels

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Altabet, M. A.; Wu, T.; Hadas, O.

    2006-12-01

    Natural ammonium N isotopic abundance has been increasingly used in studies of marine and freshwater biogeochemistry. However, current methods are time-consuming, subject to interference from DON, and not reliable at low concentrations. Our new method for determining the δ15N of ammonium overcomes these difficulties by employing the oxidation of ammonium to nitrite followed by conversion of nitrite to nitrous oxide. In the first step, ammonium is quantitatively oxidized by hypobromite at pH~12. After the addition of sodium arsenite to consume excess hypobromite, yield is verified by colorimetric NO2-measurement using sulfanilamide and naphthyl ethylenediamine (NED). Nitrite is further reduced to N2O by a 1:1 sodium azide and acetic acid buffer solution using previously established procedures. Buffer concentration can be varied according to sample matrix to ensure that a reaction pH between 2 and 4 is reached. The product nitrous oxide is then isotopically analyzed using a continuous flow purge and cryogenic trap system coupled to an isotope ratio mass spectrometer. Reliable δ15N values (±0.31‰) are obtained over a concentration range of 0.5 μM to 20 μM using 20 ml volumes of either fresh or seawater samples. Reagent blanks are very low, about 0.05 μM. There is no interference from any of the nitrogen containing compounds tested except short chain aliphatic amino acid (i.e. glycine) which typically are not present at sufficiently high environmental concentrations to pose a problem.

  11. Chemical method for nitrogen isotopic analysis of ammonium at natural abundance.

    PubMed

    Liu, Dongwei; Fang, Yunting; Tu, Ying; Pan, Yuepeng

    2014-04-15

    We report a new chemical method to determine the (15)N natural abundance (δ(15)N) for ammonium (NH4(+)) in freshwater (e.g., precipitation) and soil KCl extract. This method is based on the isotopic analysis of nitrous oxide (N2O). Ammonium is initially oxidized to nitrite (NO2(-)) by hypobromite (BrO(-)) using previously established procedures. NO2(-) is then quantitatively converted into N2O by hydroxylamine (NH2OH) under strongly acid conditions. The produced N2O is analyzed by a commercially available purge and cryogenic trap system coupled to an isotope ratio mass spectrometer (PT-IRMS). On the basis of a typical analysis size of 4 mL, the standard deviation of δ(15)N measurements is less than 0.3‰ and often better than 0.1‰ (3 to 5 replicates). Compared to previous methods, the technique here has several advantages and the potential to be used as a routine method for (15)N/(14)N analysis of NH4(+): (1) substantially simplified preparation procedures and reduced preparation time particularly compared to the methods in which diffusion or distillation is involved since all reactions occur in the same vial and separation of NH4(+) from solution is not required; (2) more suitability for low volume samples including those with low N concentration, having a blank size of 0.6 to 2 nmol; (3) elimination of the use of extremely toxic reagents (e.g., HN3) and/or the use of specialized denitrifying bacterial cultures which may be impractical for many laboratories. PMID:24654992

  12. Natural abundance carbon-13 nuclear magnetic resonance studies of histone and DNA dynamics in nucleosome cores.

    PubMed

    Hilliard, P R; Smith, R M; Rill, R L

    1986-05-01

    Natural abundance carbon-13 nuclear magnetic resonance spectra (67.9 MHz) were obtained for native nucleosome cores: cores dissociated in 2 M NaCl and 2 M NaCl, 6 M urea; and cores degraded with DNase I plus proteinase K. Phosphorus-31 NMR spectra of native and dissociated cores and core length DNA were also obtained at 60.7 MHz. The 31P resonance and spin-lattice relaxation time (T1) of DNA were only slightly affected by packaging in nucleosome cores, in agreement with other reports, but 13C resonances of DNA were essentially unobservable. The loss of DNA spectral intensity suggests that rapid internal motions of DNA sugar carbons in protein-free DNA previously demonstrated by 13C NMR methods are partly restricted in nucleosomes. The 13C spectrum of native cores contains many narrow intense resonances assigned to lysine side chain and alpha-carbons, glycine alpha-carbons, alanine alpha- and beta- carbons, and arginine side chain carbons. Several weaker resonances were also assigned. The narrow line widths, short T1 values, and non-minimal nuclear Overhauser enhancements of these resonances, including alpha- and beta-carbons, show that some terminal chain segments of histones in nucleosomes are as mobile as small random coil polypeptides. The mobile segments include about 9% of all histone residues and 25% of all lysines, but only 10% of all arginines. The compositions of these segments indicate that mobile regions are located in amino- or carboxyl-terminal sequences of two or more histones. In addition, high mobility was observed for side chain carbons of 45-50% of all lysines (delta and epsilon carbons) and about 25% of all arginines (zeta carbon) in histones (including those in mobile segments), suggesting that basic residues in terminal histone sequences are not strongly involved in nucleosome structure and may instead help stabilize higher order chromatin structure. PMID:3700380

  13. Critical evaluation of 13C natural abundance techniques to partition soil-surface CO2 efflux

    NASA Astrophysics Data System (ADS)

    Snell, H.; Midwood, A. J.; Robinson, D.

    2013-12-01

    Soil is the largest terrestrial store of carbon and the flux of CO2 from soils to the atmosphere is estimated at around 98 Pg (98 billion tonnes) of carbon per year. The CO2 efflux from the soil surface is derived from plant root and rhizosphere respiration (autotrophically fuelled) and microbial degradation of soil organic matter (heterotrophic respiration). Heterotrophic respiration is a key determinant of an ecosystem's long-term C balance, but one that is difficult to measure in the field. One approach involves partitioning the total soil-surface CO2 efflux between heterotrophic and autotrophic components; this can be done using differences in the natural abundance stable isotope ratios (δ13C) of autotrophic and heterotrophic CO2 as the end-members of a simple mixing model. In most natural, temperate ecosystems, current and historical vegetation cover (and therefore also plant-derived soil organic matter) is produced from C3 photosynthesis so the difference in δ13C between the autotrophic and heterotrophic CO2 sources is small. Successful partitioning therefore requires accurate and precise measurements of the δ13CO2 of the autotrophic and heterotrophic end-members (obtained by measuring the δ13CO2 of soil-free roots and root-free soil) and of total soil CO2 efflux. There is currently little consensus on the optimum measurement protocols. Here we systematically tested some of the most commonly used techniques to identify and minimise methodological errors. Using soil-surface chambers to sample total CO2 efflux and a cavity ring-down spectrometer to measure δ13CO2 in a partitioning study on a Scottish moorland, we found that: using soil-penetrating collars leads to a more depleted chamber measurement of total soil δ13CO2 as a result of severing roots and fungal hyphae or equilibrating with δ13CO2 at depth or both; root incubations provide an accurate estimate of in-situ root respired δ13CO2 provided they are sampled within one hour; the δ13CO2 from root

  14. Interactions between natural-occurring landscape conditions and land use influencing the abundance of riverine smallmouth bass, micropterus dolomieu

    USGS Publications Warehouse

    Brewer, S.K.; Rabeni, C.F.

    2011-01-01

    This study examined how interactions between natural landscape features and land use influenced the abundance of smallmouth bass, Micropterus dolomieu, in Missouri, USA, streams. Stream segments were placed into one of four groups based on natural-occurring watershed characteristics (soil texture and soil permeability) predicted to relate to smallmouth bass abundance. Within each group, stream segments were assigned forest (n = 3), pasture (n = 3), or urban (n = 3) designations based on the percentages of land use within each watershed. Analyses of variance indicated smallmouth bass densities differed between land use and natural conditions. Decision tree models indicated abundance was highest in forested stream segments and lowest in urban stream segments, regardless of group designation. Land use explained the most variation in decision tree models, but in-channel features of temperature, flow, and sediment also contributed significantly. These results are unique and indicate the importance of natural-occurring watershed conditions in defining the potential of populations and how finer-scale filters interact with land use to further alter population potential. Smallmouth bass has differing vulnerabilities to land-use attributes, and the better the natural watershed conditions are for population success, the more resilient these populations will be when land conversion occurs.

  15. Natural abundance (14)N and (15)N solid-state NMR of pharmaceuticals and their polymorphs.

    PubMed

    Veinberg, Stanislav L; Johnston, Karen E; Jaroszewicz, Michael J; Kispal, Brianna M; Mireault, Christopher R; Kobayashi, Takeshi; Pruski, Marek; Schurko, Robert W

    2016-06-29

    (14)N ultra-wideline (UW), (1)H{(15)N} indirectly-detected HETCOR (idHETCOR) and (15)N dynamic nuclear polarization (DNP) solid-state NMR (SSNMR) experiments, in combination with plane-wave density functional theory (DFT) calculations of (14)N EFG tensors, were utilized to characterize a series of nitrogen-containing active pharmaceutical ingredients (APIs), including HCl salts of scopolamine, alprenolol, isoprenaline, acebutolol, dibucaine, nicardipine, and ranitidine. A case study applying these methods for the differentiation of polymorphs of bupivacaine HCl is also presented. All experiments were conducted upon samples with naturally-abundant nitrogen isotopes. For most of the APIs, it was possible to acquire frequency-stepped UW (14)N SSNMR spectra of stationary samples, which display powder patterns corresponding to pseudo-tetrahedral (i.e., RR'R''NH(+) and RR'NH2(+)) or other (i.e., RNH2 and RNO2) nitrogen environments. Directly-excited (14)N NMR spectra were acquired using the WURST-CPMG pulse sequence, which incorporates WURST (wideband, uniform rate, and smooth truncation) pulses and a CPMG (Carr-Purcell Meiboom-Gill) refocusing protocol. In certain cases, spectra were acquired using (1)H → (14)N broadband cross-polarization, via the BRAIN-CP (broadband adiabatic inversion - cross polarization) pulse sequence. These spectra provide (14)N electric field gradient (EFG) tensor parameters and orientations that are particularly sensitive to variations in local structure and intermolecular hydrogen-bonding interactions. The (1)H{(15)N} idHETCOR spectra, acquired under conditions of fast magic-angle spinning (MAS), used CP transfers to provide (1)H-(15)N chemical shift correlations for all nitrogen environments, except for two sites in acebutolol and nicardipine. One of these two sites (RR'NH2(+) in acebutolol) was successfully detected using the DNP-enhanced (15)N{(1)H} CP/MAS measurement, and one (RNO2 in nicardipine) remained elusive due to the absence of

  16. The natural 13C abundance of plasma glucose is a useful biomarker of recent dietary caloric sweetener intake.

    PubMed

    Cook, Chad M; Alvig, Amy L; Liu, Yu Qiu David; Schoeller, Dale A

    2010-02-01

    There is a need for objective biomarkers of dietary intake, because self-reporting is often subject to bias. We tested the validity of a biomarker for the fraction of dietary carbohydrate (CHO) from cane sugar and high fructose corn syrup (C(4) sugars) using natural (13)C abundance of plasma glucose. In a randomized, single-blinded, crossover design, 5 participants consumed 3 weight-maintaining diets for 7 d, with a 2-wk washout between diet periods. Diets differed in the fraction of total CHO energy from C(4) sugars (5, 16, or 32%). During each diet period, blood samples were drawn at hours 0800 and 1600 on d 1, 3, and 5 and at 0800, 1000, 1200, 1400, and 1600 on d 7. The delta(13)C abundance of plasma glucose was analyzed via GC- isotope ratio MS. Within each diet period, delta(13)C abundance of the 0800 fasting glucose did not change from baseline with increasing time during a diet period; however, there was a strong positive correlation (R(2) = 0.89) between delta(13)C abundance of the glucose concentration at 1000 on d 7 and the percent of breakfast CHO from C(4) sugars. Also, delta(13)C abundance of the combined plasma glucose samples on d 7 demonstrated a strong positive correlation (R(2) = 0.90) with the percent of total daily CHO from C(4) sugars. The natural delta(13)C abundance of postprandial plasma glucose relative to dietary C(4) CHO content was a valid biomarker for contributions of C(4) caloric sweeteners from the previous meal. PMID:20018804

  17. Natural abundance 17O DNP two-dimensional and surface-enhanced NMR spectroscopy

    SciTech Connect

    Perras, Frédéric A.; Kobayashi, Takeshi; Pruski, Marek

    2015-06-22

    Due to its extremely low natural abundance and quadrupolar nature, the 17O nuclide is very rarely used for spectroscopic investigation of solids by NMR without isotope enrichment. Additionally, the applicability of dynamic nuclear polarization (DNP), which leads to sensitivity enhancements of 2 orders of magnitude, to 17O is wrought with challenges due to the lack of spin diffusion and low polarization transfer efficiency from 1H. Here, we demonstrate new DNP-based measurements that extend 17O solid-state NMR beyond its current capabilities. The use of the PRESTO technique instead of conventional 1H–17O cross-polarization greatly improves the sensitivity and enables the facile measurement of undistorted line shapes and two-dimensional 1H–17O HETCOR NMR spectra as well as accurate internuclear distance measurements at natural abundance. This was applied for distinguishing hydrogen-bonded and lone 17O sites on the surface of silica gel; the one-dimensional spectrum of which could not be used to extract such detail. As a result, this greatly enhanced sensitivity has enabled, for the first time, the detection of surface hydroxyl sites on mesoporous silica at natural abundance, thereby extending the concept of DNP surface-enhanced NMR spectroscopy to the 17O nuclide.

  18. Is the Multicolored Asian Ladybeetle, Harmonia axyridis, the Most Abundant Natural Enemy to Aphids in Agroecosystems?

    PubMed Central

    Vandereycken, Axel; Durieux, Delphine; Joie, Emilie; Sloggett, John J.; Haubruge, Eric; Verheggen, François J.

    2013-01-01

    The multicolored Asian ladybeetle, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was introduced into Western Europe in the late 1990s. Since the late 2000s, this species has been commonly considered one of the most abundant aphid predators in most Western European countries. In spite of the large amount of research on H. axyridis, information concerning its relative abundance in agroecosystems is lacking. This study aims to evaluate the abundance of H. axyridis within the aphidophage community in four crops situated in southern Belgium: wheat, Triticum aestivum L. (Poales: Poaceae), corn, Zea mays, potato, Solanum tuberosum (Solanales: Solanaceae), and broad bean Vicia faba (Fabales: Fabaceae). In order to assess the species diversity, the collected data were analyzed by considering (1) the species richness and (2) the evenness according to the Shannon diversity index. Eleven aphidophages were observed in every inventoried agroecosystem, including five abundant species: three coccinellids, the seven-spotted ladybug, Coccinella septempunctata L. (Coleoptera: Coccinellidae), the 14-spotted Ladybird, Propylea quatuordecimpunctata, and H. axyridis; one hoverfly, the marmalade hoverfly, Episyrphus balteatus De Geer (Diptera: Syrphidae); and one lacewing, the common green lacewing, Chrysoperla carnea Stephens sensu lato (= s.l.) (Neuroptera: Chrysopidae). Harmonia axyridis has been observed to thrive, breed, and reproduce on the four studied crops. Harmonia axyridis is the most abundant predator of aphids in corn followed by C. septempunctata, which is the main aphid predator observed in the three other inventoried crops. In wheat and potato fields, H. axyridis occurs in low numbers compared to other aphidophage. These observations suggest that H. axyridis could be considered an invasive species of agrosystems, and that potato and wheat may intermittently act as refuges for other aphidophages vulnerable to intraguild predation by this invader. Harmonia axyridis

  19. Is the multicolored Asian ladybeetle, Harmonia axyridis, the most abundant natural enemy to aphids in agroecosystems?

    PubMed

    Vandereycken, Axel; Durieux, Delphine; Joie, Emilie; Sloggett, John J; Haubruge, Eric; Verheggen, François J

    2013-01-01

    The multicolored Asian ladybeetle, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was introduced into Western Europe in the late 1990s. Since the late 2000s, this species has been commonly considered one of the most abundant aphid predators in most Western European countries. In spite of the large amount of research on H. axyridis, information concerning its relative abundance in agroecosystems is lacking. This study aims to evaluate the abundance of H. axyridis within the aphidophage community in four crops situated in southern Belgium: wheat, Triticum aestivum L. (Poales: Poaceae), corn, Zea mays, potato, Solanum tuberosum (Solanales: Solanaceae), and broad bean Vicia faba (Fabales: Fabaceae). In order to assess the species diversity, the collected data were analyzed by considering (1) the species richness and (2) the evenness according to the Shannon diversity index. Eleven aphidophages were observed in every inventoried agroecosystem, including five abundant species: three coccinellids, the seven-spotted ladybug, Coccinella septempunctata L. (Coleoptera: Coccinellidae), the 14-spotted Ladybird, Propylea quatuordecimpunctata, and H. axyridis; one hoverfly, the marmalade hoverfly, Episyrphus balteatus De Geer (Diptera: Syrphidae); and one lacewing, the common green lacewing, Chrysoperla carnea Stephens sensu lato (= s.l.) (Neuroptera: Chrysopidae). Harmonia axyridis has been observed to thrive, breed, and reproduce on the four studied crops. Harmonia axyridis is the most abundant predator of aphids in corn followed by C. septempunctata, which is the main aphid predator observed in the three other inventoried crops. In wheat and potato fields, H. axyridis occurs in low numbers compared to other aphidophage. These observations suggest that H. axyridis could be considered an invasive species of agrosystems, and that potato and wheat may intermittently act as refuges for other aphidophages vulnerable to intraguild predation by this invader. Harmonia axyridis

  20. Increased seawater temperature increases the abundance and alters the structure of natural Vibrio populations associated with the coral Pocillopora damicornis.

    PubMed

    Tout, Jessica; Siboni, Nachshon; Messer, Lauren F; Garren, Melissa; Stocker, Roman; Webster, Nicole S; Ralph, Peter J; Seymour, Justin R

    2015-01-01

    Rising seawater temperature associated with global climate change is a significant threat to coral health and is linked to increasing coral disease and pathogen-related bleaching events. We performed heat stress experiments with the coral Pocillopora damicornis, where temperature was increased to 31°C, consistent with the 2-3°C predicted increase in summer sea surface maxima. 16S rRNA amplicon sequencing revealed a large shift in the composition of the bacterial community at 31°C, with a notable increase in Vibrio, including known coral pathogens. To investigate the dynamics of the naturally occurring Vibrio community, we performed quantitative PCR targeting (i) the whole Vibrio community and (ii) the coral pathogen Vibrio coralliilyticus. At 31°C, Vibrio abundance increased by 2-3 orders of magnitude and V. coralliilyticus abundance increased by four orders of magnitude. Using a Vibrio-specific amplicon sequencing assay, we further demonstrated that the community composition shifted dramatically as a consequence of heat stress, with significant increases in the relative abundance of known coral pathogens. Our findings provide quantitative evidence that the abundance of potential coral pathogens increases within natural communities of coral-associated microbes as a consequence of rising seawater temperature and highlight the potential negative impacts of anthropogenic climate change on coral reef ecosystems. PMID:26042096

  1. Increased seawater temperature increases the abundance and alters the structure of natural Vibrio populations associated with the coral Pocillopora damicornis

    PubMed Central

    Tout, Jessica; Siboni, Nachshon; Messer, Lauren F.; Garren, Melissa; Stocker, Roman; Webster, Nicole S.; Ralph, Peter J.; Seymour, Justin R.

    2015-01-01

    Rising seawater temperature associated with global climate change is a significant threat to coral health and is linked to increasing coral disease and pathogen-related bleaching events. We performed heat stress experiments with the coral Pocillopora damicornis, where temperature was increased to 31°C, consistent with the 2–3°C predicted increase in summer sea surface maxima. 16S rRNA amplicon sequencing revealed a large shift in the composition of the bacterial community at 31°C, with a notable increase in Vibrio, including known coral pathogens. To investigate the dynamics of the naturally occurring Vibrio community, we performed quantitative PCR targeting (i) the whole Vibrio community and (ii) the coral pathogen Vibrio coralliilyticus. At 31°C, Vibrio abundance increased by 2–3 orders of magnitude and V. coralliilyticus abundance increased by four orders of magnitude. Using a Vibrio-specific amplicon sequencing assay, we further demonstrated that the community composition shifted dramatically as a consequence of heat stress, with significant increases in the relative abundance of known coral pathogens. Our findings provide quantitative evidence that the abundance of potential coral pathogens increases within natural communities of coral-associated microbes as a consequence of rising seawater temperature and highlight the potential negative impacts of anthropogenic climate change on coral reef ecosystems. PMID:26042096

  2. Assessment of the natural variation of low abundant metabolic proteins in soybean seeds using proteomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry, we investigated the distribution of the low abundant proteins that are involved in soybean seed development in four wild and twelve cultivated soybean genotypes. We found proteomic variation of these proteins within and...

  3. Quantifying the value that energy efficiency and renewable energy provide as a hedge against volatile natural gas prices

    SciTech Connect

    Bolinger, Mark; Wiser, Ryan; Bachrach, Devra; Golove, William

    2002-05-15

    Advocates of energy efficiency and renewable energy have long argued that such technologies can mitigate fuel price risk within a resource portfolio. Such arguments--made with renewed vigor in the wake of unprecedented natural gas price volatility during the winter of 2000/2001--have mostly been qualitative in nature, however, with few attempts to actually quantify the price stability benefit that these sources provide. In evaluating this benefit, it is important to recognize that alternative price hedging instruments are available--in particular, gas-based financial derivatives (futures and swaps) and physical, fixed-price gas contracts. Whether energy efficiency and renewable energy can provide price stability at lower cost than these alternative means is therefore a key question for resource acquisition planners. In this paper we evaluate the cost of hedging gas price risk through financial hedging instruments. To do this, we compare the price of a 10-year natural gas swap (i.e., what it costs to lock in prices over the next 10 years) to a 10-year natural gas price forecast (i.e., what the market is expecting spot natural gas prices to be over the next 10 years). We find that over the past two years natural gas users have had to pay a premium as high as $0.76/mmBtu (0.53/242/kWh at an aggressive 7,000 Btu/kWh heat rate) over expected spot prices to lock in natural gas prices for the next 10 years. This incremental cost to hedge gas price risk exposure is potentially large enough - particularly if incorporated by policymakers and regulators into decision-making practices - to tip the scales away from new investments in variable-price, natural gas-fired generation and in favor of fixed-price investments in energy efficiency and renewable energy.

  4. Flow and habitat effects on juvenile fish abundance in natural and altered flow regimes

    USGS Publications Warehouse

    Freeman, Mary C.; Bowen, Z.H.; Bovee, K.D.; Irwin, E.R.

    2001-01-01

    Conserving biological resources native to large river systems increasingly depends on how flow-regulated segments of these rivers are managed. Improving management will require a better understanding of linkages between river biota and temporal variability of flow and instream habitat. However, few studies have quantified responses of native fish populations to multiyear (>2 yr) patterns of hydrologic or habitat variability in flow-regulated systems. To provide these data, we quantified young-of-year (YOY) fish abundance during four years in relation to hydrologic and habitat variability in two segments of the Tallapoosa River in the southeastern United States. One segment had an unregulated flow regime, whereas the other was flow-regulated by a peak-load generating hydropower dam. We sampled fishes annually and explored how continuously recorded flow data and physical habitat simulation models (PHABSIM) for spring (April-June) and summer (July-August) preceding each sample explained fish abundances. Patterns of YOY abundance in relation to habitat availability (median area) and habitat persistence (longest period with habitat area continuously above the long-term median area) differed between unregulated and flow-regulated sites. At the unregulated site, YOY abundances were most frequently correlated with availability of shallow-slow habitat in summer (10 species) and persistence of shallow-slow and shallow-fast habitat in spring (nine species). Additionally, abundances were negatively correlated with 1-h maximum flow in summer (five species). At the flow-regulated site, YOY abundances were more frequently correlated with persistence of shallow-water habitats (four species in spring; six species in summer) than with habitat availability or magnitude of flow extremes. The associations of YOY with habitat persistence at the flow-regulated site corresponded to the effects of flow regulation on habitat patterns. Flow regulation reduced median flows during spring and

  5. Heteronuclear NMR of DNA with the heteronucleus in natural abundance: facilitated assignment and extraction of coupling constants.

    PubMed Central

    Schmieder, P; Ippel, J H; van den Elst, H; van der Marel, G A; van Boom, J H; Altona, C; Kessler, H

    1992-01-01

    Two heteronuclear proton-carbon NMR experiments are applied to the DNA-octamer d(TTGGCCAA)2 with carbon in natural abundance. They lead to a complete assignment of the carbon resonances of the sugars and bases. In addition, several heteronuclear coupling constants, proton-carbon as well as proton-phosphorous and phosphorous-carbon, were determined. The information can be obtained in a reasonable measuring time and offers valuable information for a detailed picture of DNA structure. PMID:1408787

  6. Optical hyperpolarization and inductive readout of 31P donor nuclei in natural abundance single crystal 29Si

    NASA Astrophysics Data System (ADS)

    Alexander, Thomas; Haas, Holger; Deshpande, Rahul; Gumann, Patryk; Cory, David

    2016-05-01

    We optically polarize and inductively detect 31P donor nuclei in single crystal silicon at high magnetic fields (6 . 7T). Samples include both natural abundance 29Si and an isotopically purified 28Si sample. We observe dipolar order in the 29Si nuclear spins through a spin-locking measurement. This provides a means of characterizing spin transport in the vicinity of the 31P donors.

  7. Unveiling the Nature of the "Green Pea" Galaxies: Oxygen and Nitrogen Chemical Abundances

    NASA Astrophysics Data System (ADS)

    Amorín, R. O.; Pérez-Montero, E.; Vílchez, J. M.

    2011-07-01

    We present recent results on the oxygen and nitrogen chemical abundances in the extremely compact, low-mass starburst galaxies at redshifts 0.1-0.3 usually referred to as "green pea" galaxies. We show that they are metal-poor galaxies (~1/5 solar) with lower oxygen abundances than star-forming galaxies of similar mass and N/O ratios unusually high for galaxies of the same metallicity. Recent, rapid, and massive inflows of cold gas, possibly coupled with enriched outflows from supernova winds, are used to explain the results. This is consistent with the known "pea" galaxy properties and suggest that these rare objects are experiencing a short and extreme phase in their evolution.

  8. Nature's starships. I. Observed abundances and relative frequencies of amino acids in meteorites

    SciTech Connect

    Cobb, Alyssa K.; Pudritz, Ralph E. E-mail: pudritz@physics.mcmaster.ca

    2014-03-10

    The class of meteorites called carbonaceous chondrites are examples of material from the solar system which have been relatively unchanged from the time of their initial formation. These meteorites have been classified according to the temperatures and physical conditions of their parent planetesimals. We collate available data on amino acid abundance in these meteorites and plot the concentrations of different amino acids for each meteorite within various meteorite subclasses. We plot average concentrations for various amino acids across meteorites separated by subclass and petrologic type. We see a predominance in the abundance and variety of amino acids in CM2 and CR2 meteorites. The range in temperature corresponding to these subclasses indicates high degrees of aqueous alteration, suggesting aqueous synthesis of amino acids. Within the CM2 and CR2 subclasses, we identify trends in relative frequencies of amino acids to investigate how common amino acids are as a function of their chemical complexity. These two trends (total abundance and relative frequencies) can be used to constrain formation parameters of amino acids within planetesimals. Our organization of the data supports an onion shell model for the temperature structure of planetesimals. The least altered meteorites (type 3) and their amino acids originated near cooler surface regions. The most active amino acid synthesis likely took place at intermediate depths (type 2). The most altered materials (type 1) originated furthest toward parent body cores. This region is likely too hot to either favor amino acid synthesis or for amino acids to be retained after synthesis.

  9. Natural decay process affects the abundance and community structure of Bacteria and Archaea in Picea abies logs.

    PubMed

    Rinta-Kanto, J M; Sinkko, H; Rajala, T; Al-Soud, W A; Sørensen, S J; Tamminen, M V; Timonen, S

    2016-07-01

    Prokaryotes colonize decaying wood and contribute to the degradation process, but the dynamics of prokaryotic communities during wood decay is still poorly understood. We studied the abundance and community composition of Bacteria and Archaea inhabiting naturally decaying Picea abies logs and tested the hypothesis that the variations in archaeal and bacterial abundances and community composition are coupled with environmental parameters related to the decay process. The data set comprises >500 logs at different decay stages from five geographical locations in south and central Finland. The results show that Bacteria and Archaea are an integral and dynamic component of decaying wood biota. The abundances of bacterial and archaeal 16S rRNA genes increase as wood decay progresses. Changes in bacterial community composition are clearly linked to the loss of density of wood, while specific fungal-bacterial interactions may also affect the distribution of bacterial taxa in decaying wood. Thaumarchaeota were prominent members of the archaeal populations colonizing decaying wood, providing further evidence of the versatility and cosmopolitan nature of this phylum in the environment. The composition and dynamics of the prokaryotic community suggest that they are an active component of biota that are involved in processing substrates in decaying wood material. PMID:27127195

  10. Does human activity impact the natural antibiotic resistance background? Abundance of antibiotic resistance genes in 21 Swiss lakes.

    PubMed

    Czekalski, Nadine; Sigdel, Radhika; Birtel, Julia; Matthews, Blake; Bürgmann, Helmut

    2015-08-01

    Antibiotic resistance genes (ARGs) are emerging environmental contaminants, known to be continuously discharged into the aquatic environment via human and animal waste. Freshwater aquatic environments represent potential reservoirs for ARG and potentially allow sewage-derived ARG to persist and spread in the environment. This may create increased opportunities for an eventual contact with, and gene transfer to, human and animal pathogens via the food chain or drinking water. However, assessment of this risk requires a better understanding of the level and variability of the natural resistance background and the extent of the human impact. We have analyzed water samples from 21 Swiss lakes, taken at sampling points that were not under the direct influence of local contamination sources and analyzed the relative abundance of ARG using quantitative real-time PCR. Copy numbers of genes mediating resistance to three different broad-spectrum antibiotic classes (sulfonamides: sul1, sul2, tetracyclines: tet(B), tet(M), tet(W) and fluoroquinolones: qnrA) were normalized to copy numbers of bacterial 16S rRNA genes. We used multiple linear regression to assess if ARG abundance is related to human activities in the catchment, microbial community composition and the eutrophication status of the lakes. Sul genes were detected in all sampled lakes, whereas only four lakes contained quantifiable numbers of tet genes, and qnrA remained below detection in all lakes. Our data indicate higher abundance of sul1 in lakes with increasing number and capacity of wastewater treatment plants (WWTPs) in the catchment. sul2 abundance was rather related to long water residence times and eutrophication status. Our study demonstrates the potential of freshwater lakes to preserve antibiotic resistance genes, and provides a reference for ARG abundance from lake systems with low human impact as a baseline for assessing ARG contamination in lake water. PMID:25913323

  11. ASSESSING ABUNDANCE DISTRIBUTIONS IN NATURAL COMMUNITIES OF ECTOMYCORRHIZAS ALONG AN ENVIRONMENTAL GRADIENT

    EPA Science Inventory

    Alpha diversity indices often fail to distinguish between natural populations that a more detailed investigation of the distribution of ramets among types would show are quite different. We studied the effectiveness of applying SHE analyses to morphotype classifications of ectom...

  12. Identification of Biodegradation Pathways in a Multi-Process Phytoremediation System (MPPS) Using Natural Abundance 14C Analysis of PLFA

    NASA Astrophysics Data System (ADS)

    Cowie, B. R.; Greenberg, B. M.; Slater, G. F.

    2008-12-01

    Optimizing remediation of petroleum-contaminated soils requires thorough understanding of the mechanisms and pathways involved in a proposed remediation system. In many engineered and natural attenuation systems, multiple degradation pathways may contribute to observed contaminant mass losses. In this study, biodegradation in the soil microbial community was identified as a major pathway for petroleum hydrocarbon removal in a Multi-Process Phytoremediation System (MPPS) using natural abundance 14C analysis of Phospholipid Fatty Acids (PLFA). In contaminated soils, PLFA were depleted in Δ14C to less than -800‰, directly demonstrating microbial uptake and utilization of petroleum derived carbon (Δ14C = -992‰) during bioremediation. Mass balance indicated that more than 80% of microbial carbon was derived from petroleum hydrocarbons and a maximum of 20% was produced from metabolism of modern carbon sources. In contrast, in a nearby uncontaminated control soil, the microbial community maintained a nearly modern 14C signature, suggesting preferential degradation of more labile, recent carbon. Mass balance using δ13C and Δ14C of soil CO2 demonstrated that mineralization of petroleum carbon contributed 60-65% of soil CO2 at the contaminated site. The remainder was derived from atmospheric (27-30%) and decomposition of non- petroleum natural organic carbon (5-10%). The clean control exhibited substantially lower CO2 concentrations that were derived from atmospheric (55%) and natural organic carbon (45%) sources. This study highlights the value of using multiple carbon isotopes to identify degradation pathways in petroleum- contaminated soils undergoing phytoremediation and the power of natural abundance 14C to detect petroleum metabolism in natural microbial communities.

  13. Nitrate dynamics in natural plants: insights based on the concentration and natural isotope abundances of tissue nitrate

    PubMed Central

    Liu, Xue-Yan; Koba, Keisuke; Makabe, Akiko; Liu, Cong-Qiang

    2014-01-01

    The dynamics of nitrate (NO−3), a major nitrogen (N) source for natural plants, has been studied mostly through experimental N addition, enzymatic assay, isotope labeling, and genetic expression. However, artificial N supply may not reasonably reflect the N strategies in natural plants because NO−3 uptake and reduction may vary with external N availability. Due to abrupt application and short operation time, field N addition, and isotopic labeling hinder the elucidation of in situ NO−3-use mechanisms. The concentration and natural isotopes of tissue NO−3 can offer insights into the plant NO−3 sources and dynamics in a natural context. Furthermore, they facilitate the exploration of plant NO−3 utilization and its interaction with N pollution and ecosystem N cycles without disturbing the N pools. The present study was conducted to review the application of the denitrifier method for concentration and isotope analyses of NO−3 in plants. Moreover, this study highlights the utility and advantages of these parameters in interpreting NO−3 sources and dynamics in natural plants. We summarize the major sources and reduction processes of NO−3 in plants, and discuss the implications of NO−3 concentration in plant tissues based on existing data. Particular emphasis was laid on the regulation of soil NO−3 and plant ecophysiological functions in interspecific and intra-plant NO−3 variations. We introduce N and O isotope systematics of NO−3 in plants and discuss the principles and feasibilities of using isotopic enrichment and fractionation factors; the correlation between concentration and isotopes (N and O isotopes: δ18O and Δ17O); and isotope mass-balance calculations to constrain sources and reduction of NO−3 in possible scenarios for natural plants are deliberated. Finally, we offer a preliminary framework of intraplant δ18O-NO−3 variation, and summarize the uncertainties in using tissue NO−3 parameters to interpret plant NO−3 utilization

  14. Natural expansion and experimental manipulation of seagrass ( Zostera spp.) abundance and the response of infaunal invertebrates

    NASA Astrophysics Data System (ADS)

    Harrison, Paul G.

    1987-06-01

    A study of an expanding seagrass bed on the south-west coast of British Columbia, Canada involved documentation and explanation of the pattern of expansion of the vegetation as well as documentation and experimental investigation of the accompanying changes in the distribution of infaunal invertebrates. Expansion followed a major environmental change, improved water clarity initiated in 1969 when a causeway blocked access to the site for silty Fraser River water. The original eelgrass ( Zostera marina) bed expanded landward over 30 m year -1, probably causing more and more water to be retained in the bed at low tide and thus improving its own habitat. More rapid expansion occurred from 1979-1983 after Z.japonica colonized at the landward edge of the eelgrass bed and in a separate intertidal area. Expansion ceased around 1983 coincident with, but probably independent of, further construction. Burrowing shrimp ( Callianassa californiensis) decreased in abundance between 1977 and 1984 in areas where the two seagrasses colonized. Short-term experiment over one summer and fall showed that removal of all shoots allowed adult shrimp and tube worms to colonize the sediment while addition of shoots of Z. japonica by transplanting caused temporary decreases in shrimp abundance. After a few weeks an established shrimp population destroyed the transplants. Among reasonable alternate hypotheses for the decline in Callianassa, the effect of sediment texture can be eliminated, but either direct negative effects of seagrass, i.e. inhibition of the burrowing of adult shrimp or of settlement of juveniles, or indirect effects, i.e. the harboring of more predators of shrimp in seagrass beds, deserve further study.

  15. Paramagnetic relaxation enhancement solid-state NMR studies of heterogeneous catalytic reaction over HY zeolite using natural abundance reactant.

    PubMed

    Zhou, Lei; Li, Shenhui; Su, Yongchao; Li, Bojie; Deng, Feng

    2015-01-01

    Paramagnetic relaxation enhancement solid-state NMR (PRE ssNMR) technique was used to investigate catalytic reaction over zeolite HY. After introducing paramagnetic Cu(II) ions into the zeolite, the enhancement of longitudinal relaxation rates of nearby nuclei, i.e.(29)Si of the framework and (13)C of the absorbents, was measured. It was demonstrated that the PRE ssNMR technique facilitated the fast acquisition of NMR signals to monitor the heterogeneous catalytic reaction (such as acetone to hydrocarbon) using natural abundance reactants. PMID:25616847

  16. Accounting for fuel price risk: Using forward natural gas prices instead of gas price forecasts to compare renewable to natural gas-fired generation

    SciTech Connect

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2003-08-13

    Against the backdrop of increasingly volatile natural gas prices, renewable energy resources, which by their nature are immune to natural gas fuel price risk, provide a real economic benefit. Unlike many contracts for natural gas-fired generation, renewable generation is typically sold under fixed-price contracts. Assuming that electricity consumers value long-term price stability, a utility or other retail electricity supplier that is looking to expand its resource portfolio (or a policymaker interested in evaluating different resource options) should therefore compare the cost of fixed-price renewable generation to the hedged or guaranteed cost of new natural gas-fired generation, rather than to projected costs based on uncertain gas price forecasts. To do otherwise would be to compare apples to oranges: by their nature, renewable resources carry no natural gas fuel price risk, and if the market values that attribute, then the most appropriate comparison is to the hedged cost of natural gas-fired generation. Nonetheless, utilities and others often compare the costs of renewable to gas-fired generation using as their fuel price input long-term gas price forecasts that are inherently uncertain, rather than long-term natural gas forward prices that can actually be locked in. This practice raises the critical question of how these two price streams compare. If they are similar, then one might conclude that forecast-based modeling and planning exercises are in fact approximating an apples-to-apples comparison, and no further consideration is necessary. If, however, natural gas forward prices systematically differ from price forecasts, then the use of such forecasts in planning and modeling exercises will yield results that are biased in favor of either renewable (if forwards < forecasts) or natural gas-fired generation (if forwards > forecasts). In this report we compare the cost of hedging natural gas price risk through traditional gas-based hedging instruments (e

  17. New method for estimating bacterial cell abundances in natural samples by use of sublimation

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Cleaves, H. James; Schubert, Michael; Aubrey, Andrew; Bada, Jeffrey L.

    2004-01-01

    We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples, including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert, were heated to a temperature of 500 degrees C for several seconds under reduced pressure. The sublimate was collected on a cold finger, and the amount of adenine released from the samples was then determined by high-performance liquid chromatography with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from approximately 10(5) to 10(9) E. coli cell equivalents per gram. For most of these samples, the sublimation-based cell counts were in agreement with total bacterial counts obtained by traditional DAPI (4,6-diamidino-2-phenylindole) staining.

  18. A thalium-doped sodium iodide well counter for radioactive tracer applications with naturally-abundant 40K

    NASA Astrophysics Data System (ADS)

    Parker, Andrew J.; Boxall, Colin; Joyce, Malcolm J.; Schotanus, Paul

    2013-09-01

    The use of a thallium-doped sodium-iodide well-type scintillation detector for the assay of the low-activity radioisotope 40K, in open-source potassium chloride aqueous solutions, is described. The hazards, safety concerns and radiowaste generation associated with using open-source radioactive isotopes can present significant difficulties, the use of hot cells and escalated costs in radioanalytical laboratory research. A solution to this is the use of low-hazard alternatives that mimic the migration and dispersion characteristics of notable fission products (in this case 137Cs). The use of NaI(Tl) as a detection medium for naturally-abundant levels of 40K in a range of media is widespread, but the use of 40K as a radioactive tracer has not been reported. The use of such low-activity sources is often complicated by the ability to detect them efficiently. In this paper a scintillator detector designed to detect the naturally-abundant 40K present in potassium chloride in tracer applications is described. Examples of the use of potassium chloride as a tracer are given in the context of ion exchange and electrochemical migration studies, and comparisons in performance are drawn from literature with hyper pure germanium semiconductor detectors, which are more commonly utilised detectors in high-resolution counting applications.

  19. Natural 15N- and 13C-abundance as indicators of forest nitrogen status and soil carbon dynamics

    SciTech Connect

    Garten Jr, Charles T; Hanson, Paul J; Todd Jr, Donald E; Lu, Benwhea Bonnie; Brice, Deanne Jane

    2007-09-01

    This book highlights new and emerging uses of stable isotope analysis in a variety of ecological disciplines. While the use of natural abundance isotopes in ecological research is now relatively standard, new techniques and ways of interpreting patterns are developing rapidly. The second edition of this book provides a thorough, up-to-date examination of these methods of research. As part of the Ecological Methods and Concepts series which provides the latest information on experimental techniques in ecology, this book looks at a wide range of techniques that use natural abundance isotopes to: {sm_bullet} follow whole ecosystem element cycling {sm_bullet} understand processes of soil organic matter formation {sm_bullet} follow the movement of water in whole watersheds {sm_bullet} understand the effects of pollution in both terrestrial and aquatic environments {sm_bullet} study extreme systems such as hydrothermal vents {sm_bullet}follow migrating organisms In each case, the book explains the background to the methodology, looks at the underlying principles and assumptions, and outlines the potential limitations and pitfalls. Stable Isotopes in Ecology and Environmental Science is an ideal resource for both ecologists who are new to isotopic analysis, and more experienced isotope ecologists interested in innovative techniques and pioneering new uses.

  20. Afforestation impacts microbial biomass and its natural (13)C and (15)N abundance in soil aggregates in central China.

    PubMed

    Wu, Junjun; Zhang, Qian; Yang, Fan; Lei, Yao; Zhang, Quanfa; Cheng, Xiaoli

    2016-10-15

    We investigated soil microbial biomass and its natural abundance of δ(13)C and δ(15)N in aggregates (>2000μm, 250-2000μm, 53-250μm and <53μm) of afforested (implementing woodland and shrubland plantations) soils, adjacent croplands and open area (i.e., control) in the Danjiangkou Reservoir area of central China. The afforested soils averaged higher microbial biomass carbon (MBC) and nitrogen (MBN) levels in all aggregates than in open area and cropland, with higher microbial biomass in micro-aggregates (<250μm) than in macro-aggregates (>2000μm). The δ(13)C of soil microbial biomass was more enriched in woodland soils than in other land use types, while δ(15)N of soil microbial biomass was more enriched compared with that of organic soil in all land use types. The δ(13)C and δ(15)N of microbial biomass were positively correlated with the δ(13)C and δ(15)N of organic soil across aggregates and land use types, whereas the (13)C and (15)N enrichment of microbial biomass exhibited linear decreases with the corresponding C:N ratio of organic soil. Our results suggest that shifts in the natural (13)C and (15)N abundance of microbial biomass reflect changes in the stabilization and turnover of soil organic matter (SOM) and thereby imply that afforestation can greatly impact SOM accumulation over the long-term. PMID:27285796

  1. Dynamic Nuclear Polarization NMR Enables the Analysis of Sn-Beta Zeolite Prepared with Natural Abundance 119Sn Precursors

    PubMed Central

    2015-01-01

    The catalytic activity of tin-containing zeolites, such as Sn-Beta, is critically dependent on the successful incorporation of the tin metal center into the zeolite framework. However, synchrotron-based techniques or solid-state nuclear magnetic resonance (ssNMR) of samples enriched with 119Sn isotopes are the only reliable methods to verify framework incorporation. This work demonstrates, for the first time, the use of dynamic nuclear polarization (DNP) NMR for characterizing zeolites containing ∼2 wt % of natural abundance Sn without the need for 119Sn isotopic enrichment. The biradicals TOTAPOL, bTbK, bCTbK, and SPIROPOL functioned effectively as polarizing sources, and the solvent enabled proper transfer of spin polarization from the radical’s unpaired electrons to the target nuclei. Using bCTbK led to an enhancement (ε) of 75, allowing the characterization of natural-abundance 119Sn-Beta with excellent signal-to-noise ratios in <24 h. Without DNP, no 119Sn resonances were detected after 10 days of continuous analysis. PMID:24697321

  2. Inferring the nature of anthropogenic threats from long-term abundance records.

    PubMed

    Shoemaker, Kevin T; Akçakaya, H Resit

    2015-02-01

    Diagnosing the processes that threaten species persistence is critical for recovery planning and risk forecasting. Dominant threats are typically inferred by experts on the basis of a patchwork of informal methods. Transparent, quantitative diagnostic tools would contribute much-needed consistency, objectivity, and rigor to the process of diagnosing anthropogenic threats. Long-term census records, available for an increasingly large and diverse set of taxa, may exhibit characteristic signatures of specific threatening processes and thereby provide information for threat diagnosis. We developed a flexible Bayesian framework for diagnosing threats on the basis of long-term census records and diverse ancillary sources of information. We tested this framework with simulated data from artificial populations subjected to varying degrees of exploitation and habitat loss and several real-world abundance time series for which threatening processes are relatively well understood: bluefin tuna (Thunnus maccoyii) and Atlantic cod (Gadus morhua) (exploitation) and Red Grouse (Lagopus lagopus scotica) and Eurasian Skylark (Alauda arvensis) (habitat loss). Our method correctly identified the process driving population decline for over 90% of time series simulated under moderate to severe threat scenarios. Successful identification of threats approached 100% for severe exploitation and habitat loss scenarios. Our method identified threats less successfully when threatening processes were weak and when populations were simultaneously affected by multiple threats. Our method selected the presumed true threat model for all real-world case studies, although results were somewhat ambiguous in the case of the Eurasian Skylark. In the latter case, incorporation of an ancillary source of information (records of land-use change) increased the weight assigned to the presumed true model from 70% to 92%, illustrating the value of the proposed framework in bringing diverse sources of

  3. Accounting for fuel price risk when comparing renewable togas-fired generation: the role of forward natural gas prices

    SciTech Connect

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2004-07-17

    Unlike natural gas-fired generation, renewable generation (e.g., from wind, solar, and geothermal power) is largely immune to fuel price risk. If ratepayers are rational and value long-term price stability, then--contrary to common practice--any comparison of the levelized cost of renewable to gas-fired generation should be based on a hedged gas price input, rather than an uncertain gas price forecast. This paper compares natural gas prices that can be locked in through futures, swaps, and physical supply contracts to contemporaneous long-term forecasts of spot gas prices. We find that from 2000-2003, forward gas prices for terms of 2-10 years have been considerably higher than most contemporaneous long-term gas price forecasts. This difference is striking, and implies that comparisons between renewable and gas-fired generation based on these forecasts over this period have arguably yielded results that are biased in favor of gas-fired generation.

  4. A New Method for Estimating Bacterial Abundances in Natural Samples using Sublimation

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Cleaves, H. James; Schubert, Michael; Aubrey, Andrew; Bada, Jeffrey L.

    2004-01-01

    We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert were heated to a temperature of 500 C for several seconds under reduced pressure. The sublimate was collected on a cold finger and the amount of adenine released from the samples then determined by high performance liquid chromatography (HPLC) with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from approx. l0(exp 5) to l0(exp 9) E. coli cell equivalents per gram. For most of these samples, the sublimation based cell counts were in agreement with total bacterial counts obtained by traditional DAPI staining. The simplicity and robustness of the sublimation technique compared to the DAPI staining method makes this approach particularly attractive for use by spacecraft instrumentation. NASA is currently planning to send a lander to Mars in 2009 in order to assess whether or not organic compounds, especially those that might be associated with life, are present in Martian surface samples. Based on our analyses of the Atacama Desert soil samples, several million bacterial cells per gam of Martian soil should be detectable using this sublimation technique.

  5. Natural landscape and stream segment attributes influencing the distribution and relative abundance of riverine smallmouth bass in Missouri

    USGS Publications Warehouse

    Brewer, S.K.; Rabeni, C.F.; Sowa, S.P.; Annis, G.

    2007-01-01

    Protecting and restoring fish populations on a regional basis are most effective if the multiscale factors responsible for the relative quality of a fishery are known. We spatially linked Missouri's statewide historical fish collections to environmental features in a geographic information system, which was used as a basis for modeling the importance of landscape and stream segment features in supporting a population of smallmouth bass Micropterus dolomieu. Decision tree analyses were used to develop probability-based models to predict statewide occurrence and within-range relative abundances. We were able to identify the range of smallmouth bass throughout Missouri and the probability of occurrence within that range by using a few broad landscape variables: the percentage of coarse-textured soils in the watershed, watershed relief, and the percentage of soils with low permeability in the watershed. The within-range relative abundance model included both landscape and stream segment variables. As with the statewide probability of occurrence model, soil permeability was particularly significant. The predicted relative abundance of smallmouth bass in stream segments containing low percentages of permeable soils was further influenced by channel gradient, stream size, spring-flow volume, and local slope. Assessment of model accuracy with an independent data set showed good concordance. A conceptual framework involving naturally occurring factors that affect smallmouth bass potential is presented as a comparative model for assessing transferability to other geographic areas and for studying potential land use and biotic effects. We also identify the benefits, caveats, and data requirements necessary to improve predictions and promote ecological understanding. ?? Copyright by the American Fisheries Society 2007.

  6. Determining the isotopic abundance of a labeled compound by mass spectrometry and how correcting for natural abundance distribution using analogous data from the unlabeled compound leads to a systematic error.

    PubMed

    Schenk, David J; Lockley, William J S; Elmore, Charles S; Hesk, Dave; Roberts, Drew

    2016-04-01

    When the isotopic abundance or specific activity of a labeled compound is determined by mass spectrometry (MS), it is necessary to correct the raw MS data to eliminate ion intensity contributions, which arise from the presence of heavy isotopes at natural abundance (e.g., a typical carbon compound contains ~1.1% (13) C per carbon atom). The most common approach is to employ a correction in which the mass-to-charge distribution of the corresponding unlabeled compound is used to subtract the natural abundance contributions from the raw mass-to-charge distribution pattern of the labeled compound. Following this correction, the residual intensities should be due to the presence of the newly introduced labeled atoms only. However, this will only be the case when the natural abundance mass isotopomer distribution of the unlabeled compound is the same as that of the labeled species. Although this may be a good approximation, it cannot be accurate in all cases. The implications of this approximation for the determination of isotopic abundance and specific activity have been examined in practice. Isotopically mixed stable-atom labeled valine batches were produced, and both these and [(14) C6 ]carbamazepine were analyzed by MS to determine the extent of the error introduced by the approach. Our studies revealed that significant errors are possible for small highly-labeled compounds, such as valine, under some circumstances. In the case with [(14) C6 ]carbamazepine, the errors introduced were minor but could be significant for (14) C-labeled compounds with particular isotopic distributions. This source of systematic error can be minimized, although not eliminated, by the selection of an appropriate isotopic correction pattern or by the use of a program that varies the natural abundance distribution throughout the correction. PMID:26916110

  7. The natural abundance of 13C with different agricultural management by NIRS with fibre optic probe technology.

    PubMed

    Fuentes, Mariela; González-Martín, Inmaculada; Hernández-Hierro, Jose Miguel; Hidalgo, Claudia; Govaerts, Bram; Etchevers, Jorge; Sayre, Ken D; Dendooven, Luc

    2009-06-30

    In the present study the natural abundance of (13)C is quantified in agricultural soils in Mexico which have been submitted to different agronomic practices, zero and conventional tillage, retention of crop residues (with and without) and rotation of crops (wheat and maize) for 17 years, which have influenced the physical, chemical and biological characteristics of the soil. The natural abundance of C13 is quantified by near infrared spectra (NIRS) with a remote reflectance fibre optic probe, applying the probe directly to the soil samples. Discriminate partial least squares analysis of the near infrared spectra allowed to classify soils with and without residues, regardless of the type of tillage or rotation systems used with a prediction rate of 90% in the internal validation and 94% in the external validation. The NIRS calibration model using a modified partial least squares regression allowed to determine the delta(13)C in soils with or without residues, with multiple correlation coefficients 0.81 and standard error prediction 0.5 per thousand in soils with residues and 0.92 and 0.2 per thousand in soils without residues. The ratio performance deviation for the quantification of delta(13)C in soil was 2.5 in soil with residues and 3.8 without residues. This indicated that the model was adequate to determine the delta(13)C of unknown soils in the -16.2 per thousand to -20.4 per thousand range. The development of the NIR calibration permits analytic determinations of the values of delta(13)C in unknown agricultural soils in less time, employing a non-destructive method, by the application of the fibre optic probe of remote reflectance to the soil sample. PMID:19376340

  8. Effects of weed cover composition on insect pest and natural enemy abundance in a field of Dracaena marginata (Asparagales: Asparagaceae) in Costa Rica.

    PubMed

    Sadof, Clifford S; Linkimer, Mildred; Hidalgo, Eduardo; Casanoves, Fernando; Gibson, Kevin; Benjamin, Tamara J

    2014-04-01

    Weeds and their influence on pest and natural enemy populations were studied on a commercial ornamental farm during 2009 in the Atlantic Zone of Costa Rica. A baseline survey of the entire production plot was conducted in February, along a 5 by 5 m grid to characterize and map initial weed communities of plants, cicadellids, katydids, and armored scales. In total, 50 plant species from 21 families were found. Seven weed treatments were established to determine how weed manipulations would affect communities of our targeted pests and natural enemies. These treatments were selected based on reported effects of specific weed cover on herbivorous insects and natural enemies, or by their use by growers as a cover crop. Treatments ranged from weed-free to being completely covered with endemic species of weeds. Although some weed treatments changed pest abundances, responses differed among arthropod pests, with the strongest effects observed for Caldwelliola and Empoasca leafhoppers. Removal of all weeds increased the abundance of Empoasca, whereas leaving mostly cyperacaeous weeds increased the abundance of Caldwelliola. Weed manipulations had no effect on the abundance of katydid and scale populations. No weed treatment reduced the abundance of all three of the target pests. Differential responses of the two leafhopper species to the same weed treatments support hypotheses, suggesting that noncrop plants can alter the abundance of pests through their effects on arthropod host finding and acceptance, as well as their impacts on natural enemies. PMID:24517852

  9. Combined analysis of C-18 unsaturated fatty acids using natural abundance deuterium 2D NMR spectroscopy in chiral oriented solvents.

    PubMed

    Lesot, Philippe; Baillif, Vincent; Billault, Isabelle

    2008-04-15

    The quantitative determination of isotopic (2H/1H)i ratios at natural abundance using the SNIF-NMR protocol is a well-known method for understanding the enzymatic biosynthesis of metabolites. However, this approach is not always successful for analyzing large solutes and, specifically, is inadequate for prochiral molecules such as complete essential unsaturated fatty acids. To overcome these analytical limitations, we use the natural abundance deuterium 2D NMR (NAD 2D NMR) spectroscopy on solutes embedded in polypeptide chiral liquid crystals. This approach, recently explored for measuring (2H/1H)i ratios of small analytes (Lesot, P.; Aroulanda, C.; Billault, I. Anal. Chem. 2004, 76, 2827-2835), is a powerful way to separate the 2H signals of all nonequivalent enantioisotopomers on the basis both of the 2H quadrupolar interactions and of the 2H chemical shift. Two significant advances over our previous work are presented here and allow the complete isotopic analysis of four mono- and polyunsaturated fatty acid methyl esters: methyl oleate (1), methyl linoleate (2), methyl linolenate (3), and methyl vernoleate (4). The first consists of using NMR spectrometers operating at higher magnetic field strength (14.1 T) and equipped with a selective cryoprobe optimized for deuterium nuclei. The second is the development of Q-COSY Fz 2D NMR experiments able to produce phased 2H 2D maps after a double Fourier transformation. This combination of modern hardware and efficient NMR sequences provides a unique tool to analyze the (2H/1H)i ratios of large prochiral molecules (C-18) dissolved in organic solutions of poly(gamma-benzyl-L-glutamate) and requires smaller amounts of solute than previous study on fatty acids. For each compound (1-4), all 2H quadrupolar doublets visible in the 2D spectra have been assigned on the basis of 2H chemical shifts, isotopic data obtained from isotropic quantitative NAD NMR, and by an interspectral comparison of the anisotropic NAD spectra of four

  10. Abundance of non-native crabs in intertidal habitats of New England with natural and artificial structure.

    PubMed

    Lovely, Christina M; O'Connor, Nancy J; Judge, Michael L

    2015-01-01

    Marine habitats containing complex physical structure (e.g., crevices) can provide shelter from predation for benthic invertebrates. To examine effects of natural and artificial structure on the abundance of intertidal juvenile crabs, 2 experiments were conducted in Kingston Bay, Massachusetts, USA, from July to September, 2012. In the first experiment, structure was manipulated in a two-factor design that was placed in the high intertidal for 3 one-week periods to test for both substrate type (sand vs. rock) and the presence or absence of artificial structure (mesh grow-out bags used in aquaculture, ∼0.5 m(2) with 62 mm(2) mesh openings). The Asian shore crab, Hemigrapsus sanguineus, and small individuals of the green crab, Carcinus maenas, were observed only in the treatments of rocks and mesh bag plus rocks. Most green crabs were small (<6 mm in carapace width) whereas H. sanguineus occurred in a wide range of sizes. In the second experiment, 3 levels of oyster-shell treatments were established using grow-out bags placed on a muddy sand substrate in the low intertidal zone: mesh grow-out bags without shells, grow-out bags with oyster shells, and grow-out bags containing live oysters. Replicate bags were deployed weekly for 7 weeks in a randomized complete block design. All crabs collected in the bags were juvenile C. maenas (1-15 mm carapace width), and numbers of crabs differed 6-fold among treatments, with most crabs present in bags with live oysters (29.5 ± 10.6 m(-2) [mean ± S.D.]) and fewest in bags without shells (4.9 ± 3.7 m(-2)). Both C. maenas and H. sanguineus occurred in habitats with natural structure (cobble rocks). The attraction of juvenile C. maenas to artificial structure consisting of plastic mesh bags containing both oyster shells and living oysters could potentially impact oyster aquaculture operations. PMID:26401456

  11. Abundance of non-native crabs in intertidal habitats of New England with natural and artificial structure

    PubMed Central

    Lovely, Christina M.; Judge, Michael L.

    2015-01-01

    Marine habitats containing complex physical structure (e.g., crevices) can provide shelter from predation for benthic invertebrates. To examine effects of natural and artificial structure on the abundance of intertidal juvenile crabs, 2 experiments were conducted in Kingston Bay, Massachusetts, USA, from July to September, 2012. In the first experiment, structure was manipulated in a two-factor design that was placed in the high intertidal for 3 one-week periods to test for both substrate type (sand vs. rock) and the presence or absence of artificial structure (mesh grow-out bags used in aquaculture, ∼0.5 m2 with 62 mm2 mesh openings). The Asian shore crab, Hemigrapsus sanguineus, and small individuals of the green crab, Carcinus maenas, were observed only in the treatments of rocks and mesh bag plus rocks. Most green crabs were small (<6 mm in carapace width) whereas H. sanguineus occurred in a wide range of sizes. In the second experiment, 3 levels of oyster-shell treatments were established using grow-out bags placed on a muddy sand substrate in the low intertidal zone: mesh grow-out bags without shells, grow-out bags with oyster shells, and grow-out bags containing live oysters. Replicate bags were deployed weekly for 7 weeks in a randomized complete block design. All crabs collected in the bags were juvenile C. maenas (1–15 mm carapace width), and numbers of crabs differed 6-fold among treatments, with most crabs present in bags with live oysters (29.5 ± 10.6 m−2 [mean ± S.D.]) and fewest in bags without shells (4.9 ± 3.7 m−2). Both C. maenas and H. sanguineus occurred in habitats with natural structure (cobble rocks). The attraction of juvenile C. maenas to artificial structure consisting of plastic mesh bags containing both oyster shells and living oysters could potentially impact oyster aquaculture operations. PMID:26401456

  12. Natural Abundance 43Ca NMR as a Tool for Exploring Calcium Biomineralization: Renal Stone Formation and Growth

    SciTech Connect

    Bowers, Geoffrey M.; Kirkpatrick, Robert J.

    2011-12-07

    Renal stone diseases are a global health issue with little effective therapeutic recourse aside from surgery and shock-wave lithotripsy, primarily because the fundamental chemical mechanisms behind calcium biomineralization are poorly understood. In this work, we show that natural abundance 43Ca NMR at 21.1 T is an effective means to probe the molecular-level Ca2+ structure in oxalate-based kidney stones. We find that the 43Ca NMR resonance of an authentic oxalate-based kidney stone cannot be explained by a single pure phase of any common Ca2+-bearing stone mineral. Combined with XRD results, our findings suggest an altered calcium oxalate monohydrate-like Ca2+ coordination environment for some fraction of Ca2+ in our sample. The evidence is consistent with existing literature hypothesizing that nonoxalate organic material interacts directly with Ca2+ at stone surfaces and is the primary driver of renal stone aggregation and growth. Our findings show that 43Ca NMR spectroscopy may provide unique and crucial insight into the fundamental chemistry of kidney stone formation, growth, and the role organic molecules play in these processes.

  13. Molecular characterization of dissolved organic matter in glacial ice: coupling natural abundance 1H NMR and fluorescence spectroscopy.

    PubMed

    Pautler, Brent G; Woods, Gwen C; Dubnick, Ashley; Simpson, André J; Sharp, Martin J; Fitzsimons, Sean J; Simpson, Myrna J

    2012-04-01

    Glaciers and ice sheets are the second largest freshwater reservoir in the global hydrologic cycle, and the onset of global climate warming has necessitated an assessment of their contributions to sea-level rise and the potential release of nutrients to nearby aquatic environments. In particular, the release of dissolved organic matter (DOM) from glacier melt could stimulate microbial activity in both glacial ecosystems and adjacent watersheds, but this would largely depend on the composition of the material released. Using fluorescence and (1)H NMR spectroscopy, we characterize DOM at its natural abundance in unaltered samples from a number of glaciers that differ in geographic location, thermal regime, and sample depth. Parallel factor analysis (PARAFAC) modeling of DOM fluorophores identifies components in the ice that are predominantly proteinaceous in character, while (1)H NMR spectroscopy reveals a mixture of small molecules that likely originate from native microbes. Spectrofluorescence also reveals a terrestrial contribution that was below the detection limits of NMR; however, (1)H nuclei from levoglucosan was identified in Arctic glacier ice samples. This study suggests that the bulk of the DOM from these glaciers is a mixture of biologically labile molecules derived from microbes. PMID:22385100

  14. Studies of minute quantities of natural abundance molecules using 2D heteronuclear correlation spectroscopy under 100kHz MAS

    SciTech Connect

    Nishiyama, Y.; Kobayashi, T.; Malon, M.; Singappuli-Arachchige, D.; Slowing, I. I.; Pruski, M.

    2015-02-16

    Two-dimensional 1H{13C} heteronuclear correlation solid-state NMR spectra of naturally abundant solid materials are presented, acquired using the 0.75-mm magic angle spinning (MAS) probe at spinning rates up to 100 kHz. In spite of the miniscule sample volume (290 nL), high-quality HSQC-type spectra of bulk samples as well as surface-bound molecules can be obtained within hours of experimental time. The experiments are compared with those carried out at 40 kHz MAS using a 1.6-mm probe, which offered higher overall sensitivity due to a larger rotor volume. The benefits of ultrafast MAS in such experiments include superior resolution in 1H dimension without resorting to 1H–1H homonuclear RF decoupling, easy optimization, and applicability to mass-limited samples. As a result, the HMQC spectra of surface-bound species can be also acquired under 100 kHz MAS, although the dephasing of transverse magnetization has significant effect on the efficiency transfer under MAS alone.

  15. Studies of minute quantities of natural abundance molecules using 2D heteronuclear correlation spectroscopy under 100kHz MAS

    DOE PAGESBeta

    Nishiyama, Y.; Kobayashi, T.; Malon, M.; Singappuli-Arachchige, D.; Slowing, I. I.; Pruski, M.

    2015-02-16

    Two-dimensional 1H{13C} heteronuclear correlation solid-state NMR spectra of naturally abundant solid materials are presented, acquired using the 0.75-mm magic angle spinning (MAS) probe at spinning rates up to 100 kHz. In spite of the miniscule sample volume (290 nL), high-quality HSQC-type spectra of bulk samples as well as surface-bound molecules can be obtained within hours of experimental time. The experiments are compared with those carried out at 40 kHz MAS using a 1.6-mm probe, which offered higher overall sensitivity due to a larger rotor volume. The benefits of ultrafast MAS in such experiments include superior resolution in 1H dimensionmore » without resorting to 1H–1H homonuclear RF decoupling, easy optimization, and applicability to mass-limited samples. As a result, the HMQC spectra of surface-bound species can be also acquired under 100 kHz MAS, although the dephasing of transverse magnetization has significant effect on the efficiency transfer under MAS alone.« less

  16. A multipurpose natural and renewable polymer in medical applications: Bacterial cellulose.

    PubMed

    de Oliveira Barud, Hélida Gomes; da Silva, Robson Rosa; da Silva Barud, Hernane; Tercjak, Agnieszka; Gutierrez, Junkal; Lustri, Wilton Rogério; de Oliveira, Osmir Batista; Ribeiro, Sidney J L

    2016-11-20

    Bacterial cellulose (BC) produced by some bacteria, among them Gluconacetobacter xylinum, which secrets an abundant 3D networks fibrils, represents an interesting emerging biocompatible nanomaterial. Since its discovery BC has shown tremendous potential in a wide range of biomedical applications, such as artificial skin, artificial blood vessels and microvessels, wound dressing, among others. BC can be easily manipulated to improve its properties and/or functionalities resulting in several BC based nanocomposites. As example BC/collagen, BC/gelatin, BC/Fibroin, BC/Chitosan, etc. Thus, the aim of this review is to discuss about the applicability in biomedicine by demonstrating a variety of forms of this biopolymer highlighting in detail some qualities of bacterial cellulose. Therefore, various biomedical applications ranging from implants and scaffolds, carriers for drug delivery, wound-dressing materials, etc. that were reported until date will be presented. PMID:27561512

  17. Natural-abundance stable carbon isotopes of small-subunit ribosomal RNA (SSU rRNA) from Guaymas Basin (Mexico)

    NASA Astrophysics Data System (ADS)

    MacGregor, B. J.; Mendlovitz, H.; Albert, D.; Teske, A. P.

    2012-12-01

    Small-subunit ribosomal RNA (SSU rRNA) is a phylogenetically informative molecule found in all species. Because it is poorly preserved in most environments, it is a useful marker for active microbial populations. We are using the natural-abundance stable carbon isotopic composition of specific microbial groups to help identify the carbon substrates contributing to microbial biomass in a variety of marine environments. At Guaymas Basin, hydrothermal fluids interact with abundant sedimentary organic carbon to produce natural gas and petroleum. Where this reaches the sediment surface, it can support dense patches of seafloor life, including Beggiatoa mats. We report here on the stable carbon isotopic composition of SSU rRNA from a Beggiatoa mat transect, a cold background site, a warm site with high oil concentration, and a second Beggiatoa mat. The central part of the transect mat overlay the steepest temperature gradient, and was visually dominated by orange Beggiatoa. This was fringed by white Beggiatoa mat and bare, but still warm, sediment. Methane concentrations were saturating beneath the orange and white mats and at the oily site, lower beneath bare sediment, and below detection at the background site. Our initial hypotheses were that rRNA isotopic composition would be strongly influenced by methane supply, and that archaeal rRNA might be lighter than bacterial due to contributions from methanogens and anaerobic methane oxidizers. We used biotin-labeled oligonucleotides to capture Bacterial and Archaeal SSU rRNA for isotopic determination. Background-site rRNA was isotopically heaviest, and bacterial RNA from below 2 cm at the oily site was lightest, consistent with control by methane. Within the transect mat, however, the pattern was more complicated; at some sediment depths, rRNA from the mat periphery was isotopically lightest. Part of this may be due to the spatially and temporally variable paths followed by hydrothermal fluid, which can include horizontal

  18. Estimation of biological nitrogen fixation by black locust in short-rotation forests using natural 15N abundance method

    NASA Astrophysics Data System (ADS)

    Veste, M.; Böhm, C.; Quinckenstein, A.; Freese, D.

    2012-04-01

    The importance of short rotation forests and agroforestry systems for woody biomass production for bioenergy will increase in Central Europe within the next decades. In this context, black locust (Robinia pseudoacacia) has a high growth potential especially at marginal, drought-susceptible sites such as occur in Brandenburg State (Eastern Germany). As a pioneer tree species black locust grows under a wide range of site conditions. The native range of black locust in Northern America is classified by a humid to sub-humid climate with a mean annual precipitation of 1020 to 1830 mm. In Central and Eastern Europe, this species is cultivated in a more continental climate with an annual precipitation often below 600 mm. Therefore, black locust is known to be relatively drought tolerant compared to other temperate, deciduous tree species. Because of its N2-fixation ability black locust plays generally an important role for the improvement of soil fertility. This effect is of particular interest at marginal sites in the post-mining landscapes. In order to estimate the N2-fixation potential of black locust at marginal sites leaf samples were taken from black locust trees in short rotation plantations planted between 1995 and 2007 in post-mining sites south of Cottbus (Brandenburg, NE Germany). The variation of the natural 15N abundance was measured to evaluate the biological nitrogen fixation. The nitrogen derived from the atmosphere can be calculated using a two-pool model from the quotient of the natural 15N abundances of the N2-fixing plant and the plant available soil N. Because representatively determining the plant available soil N is difficult, a non-N2-fixing reference plant growing at the same site with a similar root system and temporal N uptake pattern to the N2-fixing plant is often used. In our case we used red oak (Quercus rubra) as a reference. The average nitrogen content in the leaves of black locust ranged from 3.1% (C/N 14.8) in 15 years old trees to 3

  19. Acceleration of natural-abundance solid-state MAS NMR measurements on bone by paramagnetic relaxation from gadolinium-DTPA.

    PubMed

    Mroue, Kamal H; Zhang, Rongchun; Zhu, Peizhi; McNerny, Erin; Kohn, David H; Morris, Michael D; Ramamoorthy, Ayyalusamy

    2014-07-01

    Reducing the data collection time without affecting the signal intensity and spectral resolution is one of the major challenges for the widespread application of multidimensional nuclear magnetic resonance (NMR) spectroscopy, especially in experiments conducted on complex heterogeneous biological systems such as bone. In most of these experiments, the NMR data collection time is ultimately governed by the proton spin-lattice relaxation times (T1). For over two decades, gadolinium(III)-DTPA (Gd-DTPA, DTPA=Diethylene triamine pentaacetic acid) has been one of the most widely used contrast-enhancement agents in magnetic resonance imaging (MRI). In this study, we demonstrate that Gd-DTPA can also be effectively used to enhance the longitudinal relaxation rates of protons in solid-state NMR experiments conducted on bone without significant line-broadening and chemical-shift-perturbation side effects. Using bovine cortical bone samples incubated in different concentrations of Gd-DTPA complex, the (1)H T1 values were calculated from data collected by (1)H spin-inversion recovery method detected in natural-abundance (13)C cross-polarization magic angle spinning (CPMAS) NMR experiments. Our results reveal that the (1)H T1 values can be successfully reduced by a factor of 3.5 using as low as 10mM Gd-DTPA without reducing the spectral resolution and thus enabling faster data acquisition of the (13)C CPMAS spectra. These results obtained from (13)C-detected CPMAS experiments were further confirmed using (1)H-detected ultrafast MAS experiments on Gd-DTPA doped bone samples. This approach considerably improves the signal-to-noise ratio per unit time of NMR experiments applied to bone samples by reducing the experimental time required to acquire the same number of scans. PMID:24881032

  20. Acceleration of natural-abundance solid-state MAS NMR measurements on bone by paramagnetic relaxation from gadolinium-DTPA

    NASA Astrophysics Data System (ADS)

    Mroue, Kamal H.; Zhang, Rongchun; Zhu, Peizhi; McNerny, Erin; Kohn, David H.; Morris, Michael D.; Ramamoorthy, Ayyalusamy

    2014-07-01

    Reducing the data collection time without affecting the signal intensity and spectral resolution is one of the major challenges for the widespread application of multidimensional nuclear magnetic resonance (NMR) spectroscopy, especially in experiments conducted on complex heterogeneous biological systems such as bone. In most of these experiments, the NMR data collection time is ultimately governed by the proton spin-lattice relaxation times (T1). For over two decades, gadolinium(III)-DTPA (Gd-DTPA, DTPA = Diethylene triamine pentaacetic acid) has been one of the most widely used contrast-enhancement agents in magnetic resonance imaging (MRI). In this study, we demonstrate that Gd-DTPA can also be effectively used to enhance the longitudinal relaxation rates of protons in solid-state NMR experiments conducted on bone without significant line-broadening and chemical-shift-perturbation side effects. Using bovine cortical bone samples incubated in different concentrations of Gd-DTPA complex, the 1H T1 values were calculated from data collected by 1H spin-inversion recovery method detected in natural-abundance 13C cross-polarization magic angle spinning (CPMAS) NMR experiments. Our results reveal that the 1H T1 values can be successfully reduced by a factor of 3.5 using as low as 10 mM Gd-DTPA without reducing the spectral resolution and thus enabling faster data acquisition of the 13C CPMAS spectra. These results obtained from 13C-detected CPMAS experiments were further confirmed using 1H-detected ultrafast MAS experiments on Gd-DTPA doped bone samples. This approach considerably improves the signal-to-noise ratio per unit time of NMR experiments applied to bone samples by reducing the experimental time required to acquire the same number of scans.

  1. Using natural abundance radiocarbon to trace the flux of petrocarbon to the seafloor following the Deepwater Horizon oil spill.

    PubMed

    Chanton, Jeffrey; Zhao, Tingting; Rosenheim, Brad E; Joye, Samantha; Bosman, Samantha; Brunner, Charlotte; Yeager, Kevin M; Diercks, Arne R; Hollander, David

    2015-01-20

    In 2010, the Deepwater Horizon accident released 4.6–6.0 × 10(11) grams or 4.1 to 4.6 million barrels of fossil petroleum derived carbon (petrocarbon) as oil into the Gulf of Mexico. Natural abundance radiocarbon measurements on surface sediment organic matter in a 2.4 × 10(10) m(2) deep-water region surrounding the spill site indicate the deposition of a fossil-carbon containing layer that included 1.6 to 2.6 × 10(10) grams of oil-derived carbon. This quantity represents between 0.5 to 9.1% of the released petrocarbon, with a best estimate of 3.0–4.9%. These values may be lower limit estimates of the fraction of the oil that was deposited on the seafloor because they focus on a limited mostly deep-water area of the Gulf, include a conservative estimate of thickness of the depositional layer, and use an average background or prespill radiocarbon value for sedimentary organic carbon that produces a conservative value. A similar approach using hopane tracer estimated that 4–31% of 2 million barrels of oil that stayed in the deep sea settled on the bottom. Converting that to a percentage of the total oil that entered into the environment (to which we normalized our estimate) converts this range to 1.8 to 14.4%. Although extrapolated over a larger area, our independent estimate produced similar values. PMID:25494527

  2. Cumulative fission yields of short-lived isotopes under natural-abundance-boron-carbide-moderated neutron spectrum

    SciTech Connect

    Finn, Erin C.; Metz, Lori A.; Greenwood, Lawrence R.; Pierson, Bruce; Wittman, Richard S.; Friese, Judah I.; Kephart, Rosara F.

    2015-04-09

    The availability of gamma spectroscopy data on samples containing mixed fission products at short times after irradiation is limited. Due to this limitation, data interpretation methods for gamma spectra of mixed fission product samples, where the individual fission products have not been chemically isolated from interferences, are not well-developed. The limitation is particularly pronounced for fast pooled neutron spectra because of the lack of available fast reactors in the United States. Samples containing the actinide isotopes 233, 235, 238U, 237Np, and 239Pu individually were subjected to a 2$ pulse in the Washington State University 1 MW TRIGA reactor. To achieve a fission-energy neutron spectrum, the spectrum was tailored using a natural abundance boron carbide capsule to absorb neutrons in the thermal and epithermal region of the spectrum. Our tailored neutron spectrum is unique to the WSU reactor facility, consisting of a soft fission spectrum that contains some measurable flux in the resonance region. This results in a neutron spectrum at greater than 0.1 keV with an average energy of 70 keV, similar to fast reactor spectra and approaching that of 235U fission. Unique fission product gamma spectra were collected from 4 minutes to 1 week after fission using single-crystal high purity germanium detectors. Cumulative fission product yields measured in the current work generally agree with published fast pooled fission product yield values from ENDF/B-VII, though a bias was noted for 239Pu. The present work contributes to the compilation of energy-resolved fission product yield nuclear data for nuclear forensic purposes.

  3. Plant and Soil Natural Abundance delta-15N: Indicators of Nitrogen Cycling in the Catskill Mountains, New York, USA

    NASA Astrophysics Data System (ADS)

    Templer, P. H.; Lovett, G. M.; Weathers, K.; Arthur, M. A.

    2002-12-01

    We examined the potential use of natural abundance 15N of plants and soils as an indicator of forest nitrogen (N) cycling rates within the Catskill Mountains, NY. These watersheds receive among the highest rates of N deposition in the northeastern United States and are beginning to show signs of N saturation. Many studies have shown a link between increased N cycling rates and 15N enrichment of soil and plant pools. Faster rates of N cycling processes, especially nitrification, lead to fractionation of 14/15N, creating N products that are relatively depleted in 15N. This can lead to enrichment of soil pools, as lighter 14N is lost from the system via leaching or denitrification. Plant N pools can become increasingly enriched as they take up 15N-enriched soil N. Despite similar amounts of N deposition across the Catskill Mountains, forests dominated by different tree species appear to vary in the amount of N retained or lost to nearby streams. To determine if plant and soil 15N could be used as indicators of N cycling rates, we collected foliage, wood, litterfall, organic and mineral soil, and fine roots from single species stands of American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), red oak (Quercus rubra), and sugar maple (Acer saccharum). Fine roots and soil 15N were highest within sugar maple stands (p<0.05). Sugar maple soils also had the highest rates of net nitrification and N leaching. Therefore, soil 15N appears to correlate with forest N retention and loss. However, 15N enrichment was highest within foliage, litterfall and wood of beech trees (p<0.05). The decoupling between foliage 15N and N cycling, as well as between 15N of foliage and fine roots, illustrates that it may not be possible to use a single plant pool as an indicator of N cycling rates.

  4. Acceleration of Natural-Abundance Solid-State MAS NMR Measurements on Bone by Paramagnetic Relaxation from Gadolinium-DTPA

    PubMed Central

    Mroue, Kamal H.; Zhang, Rongchun; Zhu, Peizhi; McNerny, Erin; Kohn, David H.; Morris, Michael D.; Ramamoorthy, Ayyalusamy

    2014-01-01

    Reducing the data collection time without affecting the signal intensity and spectral resolution is one of the major challenges for the widespread application of multidimensional nuclear magnetic resonance (NMR) spectroscopy, especially in experiments conducted on complex heterogeneous biological systems such as bone. In most of these experiments, the NMR data collection time is ultimately governed by the proton spin-lattice relaxation times (T1). For over two decades, gadolinium(III)-DTPA (Gd-DTPA, DTPA = Diethylenetriamine pentaacetic acid) has been one of the most widely used contrast-enhancement agents in magnetic resonance imaging (MRI). In this study, we demonstrate that Gd-DTPA can also be effectively used to enhance the longitudinal relaxation rates of protons in solid-state NMR experiments conducted on bone without significant line-broadening and chemical-shift-perturbation side effects. Using bovine cortical bone samples incubated in different concentrations of Gd-DTPA complex, the 1H T1 values were calculated from data collected by 1H spin-inversion recovery method detected in natural-abundance 13C cross-polarization magic angle spinning (CPMAS) NMR experiments. Our results reveal that the 1H T1 values can be successfully reduced by a factor of 3.5 using as low as 10 mM Gd-DTPA without reducing the spectral resolution and thus enabling faster data acquisition of the 13C CPMAS spectra. These results obtained from 13C-detected CPMAS experiments were further confirmed using 1H-detected ultrafast MAS experiments on Gd-DTPA doped bone samples. This approach considerably improves the signal-to-noise ratio per unit time of NMR experiments applied to bone samples by reducing the experimental time required to acquire the same number of scans. PMID:24881032

  5. Evaluating microbial carbon sources in Athabasca oil sands tailings ponds using natural abundance stable and radiocarbon isotopes

    NASA Astrophysics Data System (ADS)

    Ahad, J. M.; Pakdel, H.

    2013-12-01

    Natural abundance stable (δ13C) and radiocarbon (Δ14C) isotopes of phospholipid fatty acids (PLFAs) were used to evaluate the carbon sources utilized by the active microbial populations in surface sediments from Athabasca oil sands tailings ponds. The absence of algal-specific PLFAs at three of the four sites investigated, in conjunction with δ13C signatures for PLFAs that were generally within ~3‰ of that reported for oil sands bitumen (~ -30‰), indicated that the microbial communities growing on petroleum constituents were dominated by aerobic heterotrophs. The Δ14C values of PLFAs ranged from -906 to -586‰ and pointed to a significant uptake of fossil carbon (up to ~90% of microbial carbon derived from petroleum), particularly in PLFAs (e.g., cy17:0 and cy19:0) often associated with petroleum hydrocarbon degrading bacteria. The comparatively higher levels of 14C in other, less specific PLFAs (e.g., 16:0) indicated the preferential uptake of younger organic matter by the general microbial population (~50-80% of microbial carbon derived from petroleum). Since the main carbon pools in tailings sediment were essentially 'radiocarbon dead' (i.e., no detectable 14C), the principal source for this modern carbon is considered to be the Athabasca River, which provides the bulk of the water used in the bitumen extraction process. The preferential uptake of the minor amount of young and presumably more biodegradable material present in systems otherwise dominated by recalcitrant petroleum constituents has important implications for remediation strategies. On the one hand, it implies that mining-related organic contaminants could persist in the environment long after tailings pond reclamation has begun. Alternatively, it may be that the young, labile organic matter provided by the Athabasca River plays an important role in stimulating or supporting the microbial utilization of petroleum carbon in oil sands tailings ponds via co-metabolism or priming processes

  6. Renewed methane increase (2007-2014): contribution of oil and natural gas emissions determined from methane and ethane column observations

    NASA Astrophysics Data System (ADS)

    Hausmann, Petra; Sussmann, Ralf; Smale, Dan

    2016-04-01

    Harmonized time series of column-averaged mole fractions of atmospheric methane and ethane over the period 1999-2014 are derived from solar Fourier transform infrared (FTIR) measurements at the Zugspitze summit (47° N, 2964 m a.s.l.) and at Lauder (45° S, 370 m a.s.l.). Long-term trend analysis reveals a consistent renewed methane increase since 2007 of 6.2 [5.6, 6.9] ppb yr‑1 at the Zugspitze and 6.0 [5.3, 6.7] ppb yr‑1 at Lauder (95 % confidence intervals). Several recent studies provide pieces of evidence that the renewed methane increase is most likely driven by two main factors: (i) increased methane emissions from tropical wetlands, followed by (ii) increased thermogenic methane emissions due to growing oil and natural gas production. Here, we quantify the magnitude of the second class of sources, using long-term measurements of atmospheric ethane as tracer for thermogenic methane emissions. In 2007, after years of weak decline, the Zugspitze ethane time series shows the sudden onset of a significant positive trend (2.3 [1.8, 2.8] × 10‑2 ppb yr‑1 for 2007-2014), while a negative trend persists at Lauder after 2007 (-0.4 [-0.6, -0.1] × 10‑2 ppb yr‑1). Zugspitze methane and ethane time series are significantly correlated for the period 2007-2014 and can be assigned to thermogenic methane emissions with an ethane-to-methane ratio of 10-21 %. We present optimized emission scenarios for 2007-2014 derived from an atmospheric two-box model. From our trend observations we infer a total ethane emission increase over the period 2007-2014 from oil and natural gas sources of 1-11 Tg yr‑1 along with an overall methane emission increase of 24-45 Tg yr‑1. Based on these results, the oil and natural gas emission contribution C to the renewed methane increase is deduced using three different emission scenarios with dedicated ranges of methane-to-ethane ratios (MER). Reference scenario 1 assumes an oil and gas emission combination with MER = 3.3-7.6, which

  7. Alaska's renewable energy potential.

    SciTech Connect

    Not Available

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  8. N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural organic matter samples of the International Humic Substances Society

    USGS Publications Warehouse

    Thorn, K.A.; Cox, L.G.

    2009-01-01

    The naturally abundant nitrogen in soil and aquatic NOM samples from the International Humic Substances Society has been characterized by solid state CP/MAS 15N NMR. Soil samples include humic and fulvic acids from the Elliot soil, Minnesota Waskish peat and Florida Pahokee peat, as well as the Summit Hill soil humic acid and the Leonardite humic acid. Aquatic samples include Suwannee River humic, fulvic and reverse osmosis isolates, Nordic humic and fulvic acids and Pony Lake fulvic acid. Additionally, Nordic and Suwannee River XAD-4 acids and Suwannee River hydrophobic neutral fractions were analyzed. Similar to literature reports, amide/aminoquinone nitrogens comprised the major peaks in the solid state spectra of the soil humic and fulvic acids, along with heterocyclic and amino sugar/terminal amino acid nitrogens. Spectra of aquatic samples, including the XAD-4 acids, contain resolved heterocyclic nitrogen peaks in addition to the amide nitrogens. The spectrum of the nitrogen enriched, microbially derived Pony Lake, Antarctica fulvic acid, appeared to contain resonances in the region of pyrazine, imine and/or pyridine nitrogens, which have not been observed previously in soil or aquatic humic substances by 15N NMR. Liquid state 15N NMR experiments were also recorded on the Elliot soil humic acid and Pony Lake fulvic acid, both to examine the feasibility of the techniques, and to determine whether improvements in resolution over the solid state could be realized. For both samples, polarization transfer (DEPT) and indirect detection (1H-15N gHSQC) spectra revealed greater resolution among nitrogens directly bonded to protons. The amide/aminoquinone nitrogens could also be observed by direct detection experiments.

  9. N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural organic matter samples of the International Humic Substances Society

    SciTech Connect

    Thorn, Kevin A.; Cox, Larry G.

    2009-02-28

    The naturally abundant nitrogen in soil and aquatic NOM samples from the International Humic Substances Society has been characterized by solid state CP/MAS ¹⁵N NMR. Soil samples include humic and fulvic acids from the Elliot soil, Minnesota Waskish peat and Florida Pahokee peat, as well as the Summit Hill soil humic acid and the Leonardite humic acid. Aquatic samples include Suwannee River humic, fulvic and reverse osmosis isolates, Nordic humic and fulvic acids and Pony Lake fulvic acid. Additionally, Nordic and Suwannee River XAD-4 acids and Suwannee River hydrophobic neutral fractions were analyzed. Similar to literature reports, amide/aminoquinone nitrogens comprised the major peaks in the solid state spectra of the soil humic and fulvic acids, along with heterocyclic and amino sugar/terminal amino acid nitrogens. Spectra of aquatic samples, including the XAD-4 acids, contain resolved heterocyclic nitrogen peaks in addition to the amide nitrogens. The spectrum of the nitrogen enriched, microbially derived Pony Lake, Antarctica fulvic acid, appeared to contain resonances in the region of pyrazine, imine and/or pyridine nitrogens, which have not been observed previously in soil or aquatic humic substances by ¹⁵N NMR. Liquid state ¹⁵N NMR experiments were also recorded on the Elliot soil humic acid and Pony Lake fulvic acid, both to examine the feasibility of the techniques, and to determine whether improvements in resolution over the solid state could be realized. For both samples, polarization transfer (DEPT) and indirect detection (¹H–¹⁵N gHSQC) spectra revealed greater resolution among nitrogens directly bonded to protons. The amide/aminoquinone nitrogens could also be observed by direct detection experiments.

  10. Quantifying nitrate retention processes in a riparian buffer zone using the natural abundance of 15N in NO3-.

    PubMed

    Dhondt, Karel; Boeckx, Pascal; Van Cleemput, Oswald; Hofman, Georges

    2003-01-01

    Quantifying the relative importance of denitrification and plant uptake to groundwater nitrate retention in riparian zones may lead to methods optimising the construction of riparian zones for water pollution control. The natural abundance of 15N in NO3- has been shown to be an interesting tool for providing insights into the NO3- retention processes occurring in riparian zones. In this study, 15N isotope fractionation (variation in delta15N of the residual NO3-) due to denitrification and due to plant uptake was measured in anaerobic soil slurries at different temperatures (5, 10 and 15 degrees C) and in hydroponic systems with different plant species (Lolium perenne L., Urtica dioica L. and Epilobium hirsutum L.). It was found that temperature had no significant effect on isotope fractionation during denitrification, which resulted in a 15N enrichment factor epsilonD of -22.5 +/- 0.6 per thousand. On the other hand, nitrate uptake by plants resulted in 15N isotope fractionation, but was independent of plant species, leading to a 15N enrichment factor epsilonP of -4.4 +/- 0.3 per thousand. By relating these two laboratory-defined enrichment factors to a field enrichment factor for groundwater nitrate retention during the growing season (epsilonR = -15.5 +/- 1.0 per thousand ), the contribution of denitrification and plant uptake to groundwater nitrate retention could be calculated. The relative importance of denitrification and plant uptake to groundwater nitrate retention in the riparian buffer zone was 49 and 51% during spring, 53 and 47% during summer, and 75 and 25% during autumn. During wintertime, high micropore dissolved organic carbon (DOC) concentrations and low redox potentials due to decomposition of the highly productive riparian vegetation probably resulted in a higher denitrification rate and favoured other nitrate retention processes such as nitrate immobilisation or dissimilatory nitrate reduction to ammonium (DNRA). This could have biased the 15N

  11. Studies of individual carbon sites of azurin from Pseudomonas aeruginosa by natural-abundance carbon-13 nuclear magnetic resonance spectroscopy.

    PubMed

    Ugurbil, K; Norton, R S; Allerhand, A; Bersohn, R

    1977-03-01

    The environments of the aromatic residues (and of the single arginine residue) of azurin from Pseudomonas aeruginosa are investigated by means of natural-abundance 13C Fourier transform NMR spectroscopy. In the case of the diamagnetic Cu(I) azurin, all 17 nonprotonated aromatic carbons (and Czota of Arg-79) yield narrow resonances. Furthermore, a single-carbon amide carbonyl resonance with an unusual chemical shift (peak chi) is observed. The pH dependence of chemical shifts is used to identify the resonances of Cgamma of titrating histidines, and of Cgamma and Czota of the two tyrosines. The resonances of Cgamma and Cdelta2 of the single tryptophan residue (and Czota of Arg-79) are also identified. The pKa values of the two tyrosines are different from each other and higher than typical values of "solvent-exposed" tyrosine residues. Two of the four histidine residues do not titrate (in the pH range 4 to 11). The resonance of Cgamma of one histidine exhibits a pH titration with fast proton exchange behavior and a pKa of 7.5 +/- 0.2. The direction of the titration shift indicates that the imidazole form of this histidine is the Ndelta1-H tautomer. The Cgamma resonance of the other titrating histidine exhibits slow exchange behavior with a pKa of about 7. The imidazole form of this histidine is the Nepsilon2-H tautomer. When going to the paramagnetic Cu(II) protein, only 11 of the 19 carbons mentioned above yield resonances that are narrow enough to be detected. Also, some of the observed resonances exhibit significant paramagnetic broadening. A comparison of spectra of fully reduced azurin, mixtures of reduced and oxidized azurin, and fully oxidized azurin yields the following information. (i) Peak chi arises from an amide group that probably is coordinated to the copper. (ii) The two nontitrating histidine residues are probably copper ligands, with Ndelta1 coordinated to the metal. (iii) The side chains of Arg-79 and the two tyrosine residues are not coordinated to

  12. Polylactide-based renewable composites from natural products residues by encapsulated film bag: characterization and biodegradability.

    PubMed

    Wu, Chin-San

    2012-09-01

    In the present study, the biodegradability, morphology, and mechanical properties of composite materials consisting of acrylic acid-grafted polylactide (PLA-g-AA) and natural products residues (corn starch, CS) were evaluated. Composites containing acrylic acid-grafted PLA (PLA-g-AA/CS) exhibited noticeably superior mechanical properties due to their greater compatibility with CS compared with PLA/CS. The feasibility of using PLA-g-AA/CS as a film bag material to facilitate the controlled release of an encapsulated phosphate-solubilizing bacterium (PSB) Burkholderia cepacia as a fertilizer use promoter was then evaluated. For purposes of comparison and accurate characterization, a PLA film bag was also assessed. The results showed that the bacterium completely degraded both the PLA and the PLA-g-AA/CS composite film bags, resulting in cell release. The PLA-g-AA/CS (20 wt%) film bags were more biodegradable than those made of PLA, and displayed a higher loss of molecular weight and intrinsic viscosity, indicating a strong connection between these characteristics and biodegradability. PMID:24751080

  13. Renewable Energy in Fitness Centers

    SciTech Connect

    Chvala, William D.

    2009-09-30

    All military installations have goals for implementing renewable energy projects, but not all have abundant solar energy or have massive feedstock for a large biomass plant. They must build up their renewable portfolio one project at it a time where they make the most sense – most of the time through small projects on specific buildings. During the last few years, Pacific Northwest National Laboratory (PNNL) provided project support to Army Installation Management Command Southeast Region (IMCOM-Southeast) installations. One of the building types visited, the physical fitness center (PFC), almost always yield project ideas. The building lends itself to a number of different technologies, and the high traffic nature is the perfect place to craft an educational message for users and demonstrate an installation’s commitment to sustainable energy development.

  14. Potential impacts of electric power production utilizing natural gas, renewables and carbon capture and sequestration on US Freshwater resources.

    PubMed

    Tidwell, Vincent C; Malczynski, Leonard A; Kobos, Peter H; Klise, Geoffrey T; Shuster, Erik

    2013-08-01

    Carbon capture and sequestration (CCS) has important implications relative to future thermoelectric water use. A bounding analysis is performed using past greenhouse gas emission policy proposals and assumes either all effected capacity retires (lower water use bound) or is retrofitted (upper bound). The analysis is performed in the context of recent trends in electric power generation expansion, namely high penetration of natural gas and renewables along with constrained cooling system options. Results indicate thermoelectric freshwater withdrawals nationwide could increase by roughly 1% or decrease by up to 60% relative to 2009 levels, while consumption could increase as much as 21% or decrease as much as 28%. To identify where changes in freshwater use might be problematic at a regional level, electric power production has been mapped onto watersheds with limited water availability (where consumption exceeds 70% of gauged streamflow). Results suggest that between 0.44 and 0.96 Mm(3)/d of new thermoelectric freshwater consumption could occur in watersheds with limited water availability, while power plant retirements in these watersheds could yield 0.90 to 1.0 Mm(3)/d of water savings. PMID:23789965

  15. Bacterial abundance and aerobic microbial activity across natural and oyster aquaculture habitats during summer conditions in a northeastern Pacific estuary.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We measured sediment properties and the abundance and functional diversity of microbes in Willapa Bay, Washington, USA, to test the response of sediment microbes to oyster aquaculture. Sites spanned the estuary gradient (salinity 24-30) and six different habitat types: eelgrass (Zostera marina), uns...

  16. Using PLFA Biomarkers and Natural Abundance Stable and Radiocarbon Isotopes to Characterize the Microbial Ecology and Metabolism of Methane Cycling

    NASA Astrophysics Data System (ADS)

    Mills, C. T.; Mandernack, K. W.; Slater, G. F.; Dias, R. F.

    2008-12-01

    Methane generated in the subsurface is a major source of atmospheric CH4, but its release is mitigated by CH4-oxidizing bacteria (methanotrophs). Therefore, it is important to understand the ecology of methanotroph communities in various environments. Phospholipid fatty acid (PLFA) analyses are a particularly useful method for characterizing these communities for two reasons: (1) Many type I and II methanotrophs produce specific PLFA biomarkers that can be used to estimate their populations, and (2) because CH4 is often very depleted in 13C and sometimes 14C, natural abundance δ13CPLFA and Δ14CPLFA values can be used to trace the flow of CH4- derived carbon through microbial ecosystems. We used these tools to evaluate the role of methanotrophs in carbon flow in three different environments: (1) a soil column overlying a coal bed methane (CBM) seep in southwest CO, and pristine, oligotrophic groundwaters within (2) sedimentary and (3) granitic host rocks in Japan. In the soil column impacted by CBM seepage, concentrations of the biomarker PLFAs for type I (16:1ω8cis) and type II (18:1ω8cis) methanotrophs were as high as 13 and 18 nmoles (g dry soil)-1, respectively. Depth profiles of methanotroph PLFA concentrations varied over different sampling dates indicating dynamic populations. δ13CPLFA values of the CBM soils (-25.1 to - 66.9‰) were substantially more negative than those for the control soil (-14.5 to -32.5‰) indicating that CBM is an important carbon source for the CBM-impacted soil microbial community. Δ14CPLFA values (-351 to -936‰) indicate the importance of 14C-dead CBM as a carbon source to the microbial communities, contributing 32 to 66% of total carbon in PLFA structures isolated from shallow soils and 67 to 97% for those isolated from deeper soils. The biomarker for type II methanotrophs, comprised 3 and 18% of total PLFAs in sedimentary and granitic groundwaters, respectively. The Δ14C values determined for type II methanotroph PLFAs

  17. Food Resources of Stream Macronivertebrates Determined by Natural-Abundance stable C and N Isotopes and a 15N Tracer Addition

    SciTech Connect

    Mulholland, P. J.

    2000-01-01

    Trophic relationships were examined using natural-abundance {sup 13}C and {sup 15}N analyses and a {sup 15}N-tracer addition experiment in Walker Branch, a 1st-order forested stream in eastern Tennessee. In the {sup 15}N-tracer addition experiment, we added {sup 15}NH{sub 4} to stream water over a 6-wk period in early spring, and measured {sup 15}N:{sup 14}N ratios in different taxa and biomass compartments over distance and time. Samples collected from a station upstream from the {sup 15}N addition provided data on natural-abundance {sup 13}C:{sup 12}C and {sup 15}N:{sup 14}N ratios. The natural-abundance {sup 15}N analysis proved to be of limited value in identifying food resources of macroinvertebrates because {sup 15}N values were not greatly different among food resources. In general, the natural-abundance stable isotope approach was most useful for determining whether epilithon or detritus were important food resources for organisms that may use both (e.g., the snail Elimia clavaeformis), and to provide corroborative evidence of food resources of taxa for which the {sup 15}N tracer results were not definitive. The {sup 15}N tracer results showed that the mayflies Stenonema spp. and Baetis spp. assimilated primarily epilithon, although Baetis appeared to assimilate a portion of the epilithon (e.g., algal cells) with more rapid N turnover than the bulk pool sampled. Although Elimia did not reach isotopic equilibrium during the tracer experiment, application of a N-turnover model to the field data suggested that it assimilated a combination of epilithon and detritus. The amphipod Gammarus minus appeared to depend mostly on fine benthic organic matter (FBOM), and the coleopteran Anchytarsus bicolor on epixylon. The caddisfly Diplectrona modesta appeared to assimilate primarily a fast N-turnover portion of the FBOM pool, and Simuliidae a fast N-turnover component of the suspended particulate organic matter pool rather than the bulk pool sampled. Together, the

  18. NREL Explores Earth-Abundant Materials for Future Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2012-10-01

    Researchers at the National Renewable Energy Laboratory (NREL) are using a theory-driven technique - sequential cation mutation - to understand the nature and limitations of promising solar cell materials that can replace today's technologies. Finding new materials that use Earth-abundant elements and are easily manufactured is important for large-scale solar electricity deployment.

  19. Constraints on abundance, composition, and nature of X-ray amorphous components of soils and rocks at Gale crater, Mars

    NASA Astrophysics Data System (ADS)

    Dehouck, Erwin; McLennan, Scott M.; Meslin, Pierre-Yves; Cousin, Agnès.

    2014-12-01

    X-ray diffraction patterns of the three samples analyzed by Curiosity's Chemistry and Mineralogy (CheMin) instrument during the first year of the Mars Science Laboratory mission—the Rocknest sand, and the John Klein and Cumberland drill fines, both extracted from the Sheepbed mudstone—show evidence for a significant amorphous component of unclear origin. We developed a mass balance calculation program that determines the range of possible chemical compositions of the crystalline and amorphous components of these samples within the uncertainties of mineral abundances derived from CheMin data. In turn, the chemistry constrains the minimum abundance of amorphous component required to have realistic compositions (all oxides ≥ 0 wt %): 21-22 wt % for Rocknest and 15-20 wt % for Cumberland, in good agreement with estimates derived from the diffraction patterns (~27 and ~31 wt %, respectively). Despite obvious differences between the Rocknest sand and the Sheepbed mudstone, the amorphous components of the two sites are chemically very similar, having comparable concentrations of SiO2, TiO2, Al2O3, Cr2O3, FeOT, CaO, Na2O, K2O, and P2O5. MgO tends to be lower in Rocknest, although it may also be comparable between the two samples depending on the exact composition of the smectite in Sheepbed. The only unambiguous difference is the SO3 content, which is always higher in Rocknest. The observed similarity suggests that the two amorphous components share a common origin or formation process. The individual phases possibly present within the amorphous components include: volcanic (or impact) glass, hisingerite (or silica + ferrihydrite), amorphous sulfates (or adsorbed SO42-), and nanophase ferric oxides.

  20. Comparing the risk profiles of renewable and natural gas electricity contracts: A summary of the California Department of Water Resources contracts

    SciTech Connect

    Bachrach, Devra; Wiser, Ryan; Bolinger, Mark; Golove, William

    2003-03-12

    Electricity markets in the United States have witnessed unprecedented instability over the last few years, with substantial volatility in wholesale market prices, significant financial distress among major industry organizations, and unprecedented legal, regulatory and legislative activity. These events demonstrate the considerable risks that exist in the electricity industry. Recent industry instability also illustrates the need for thoughtful resource planning to balance the cost, reliability, and risk of the electricity supplied to end-use customers. In balancing different supply options, utilities, regulators, and other resource planners must consider the unique risk profiles of each generating source. This paper evaluates the relative risk profiles of renewable and natural gas generating plants. The risks that exist in the electricity industry depend in part on the technologies that are used to generate electricity. Natural gas has become the fuel of choice for new power plant additions in the United States. To some, this emphasis on a single fuel source signals the potential for increased risk. Renewable generation sources, on the other hand, are frequently cited as a potent source of socially beneficial risk reduction relative to natural gas-fired generation. Renewable generation is not risk free, however, and also imposes certain costs on the electricity sector. This paper specifically compares the allocation and mitigation of risks in long-term natural gas-fired electricity contracts with the allocation and mitigation of these same risks in long-term renewable energy contracts. This comparison highlights some of the key differences between renewable and natural gas generation that decision makers should consider when making electricity investment and contracting decisions. Our assessment is relevant in both regulated and restructured markets. In still-regulated markets, the audience for this report clearly includes regulators and the utilities they

  1. Waste-to-wheel analysis of anaerobic-digestion-based renewable natural gas pathways with the GREET model.

    SciTech Connect

    Han, J.; Mintz, M.; Wang, M.

    2011-12-14

    In 2009, manure management accounted for 2,356 Gg or 107 billion standard cubic ft of methane (CH{sub 4}) emissions in the United States, equivalent to 0.5% of U.S. natural gas (NG) consumption. Owing to the high global warming potential of methane, capturing and utilizing this methane source could reduce greenhouse gas (GHG) emissions. The extent of that reduction depends on several factors - most notably, how much of this manure-based methane can be captured, how much GHG is produced in the course of converting it to vehicular fuel, and how much GHG was produced by the fossil fuel it might displace. A life-cycle analysis was conducted to quantify these factors and, in so doing, assess the impact of converting methane from animal manure into renewable NG (RNG) and utilizing the gas in vehicles. Several manure-based RNG pathways were characterized in the GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model, and their fuel-cycle energy use and GHG emissions were compared to petroleum-based pathways as well as to conventional fossil NG pathways. Results show that despite increased total energy use, both fossil fuel use and GHG emissions decline for most RNG pathways as compared with fossil NG and petroleum. However, GHG emissions for RNG pathways are highly dependent on the specifics of the reference case, as well as on the process energy emissions and methane conversion factors assumed for the RNG pathways. The most critical factors are the share of flared controllable CH{sub 4} and the quantity of CH{sub 4} lost during NG extraction in the reference case, the magnitude of N{sub 2}O lost in the anaerobic digestion (AD) process and in AD residue, and the amount of carbon sequestered in AD residue. In many cases, data for these parameters are limited and uncertain. Therefore, more research is needed to gain a better understanding of the range and magnitude of environmental benefits from converting animal manure to RNG via AD.

  2. Seasonal variation in species composition and abundance of demersal fish and invertebrates in a Seagrass Natural Reserve on the eastern coast of the Shandong Peninsula, China

    NASA Astrophysics Data System (ADS)

    Xu, Qiang; Guo, Dong; Zhang, Peidong; Zhang, Xiumei; Li, Wentao; Wu, Zhongxin

    2016-03-01

    Seagrass habitats are structurally complex ecosystems, which support high productivity and biodiversity. In temperate systems the density of seagrass may change seasonally, and this may influence the associated fish and invertebrate community. Little is known about the role of seagrass beds as possible nursery areas for fish and invertebrates in China. To study the functioning of a seagrass habitat in northern China, demersal fish and invertebrates were collected monthly using traps, from February 2009 to January 2010. The density, leaf length and biomass of the dominant seagrass Zostera marina and water temperature were also measured. The study was conducted in a Seagrass Natural Reserve (SNR) on the eastern coast of the Shandong Peninsula, China. A total of 22 fish species and five invertebrate species were recorded over the year. The dominant fish species were Synechogobius ommaturus, Sebastes schlegelii, Pholis fangi, Pagrus major and Hexagrammos otakii and these species accounted for 87% of the total number of fish. The dominant invertebrate species were Charybdis japonica and Octopus variabilis and these accounted for 98% of the total abundance of invertebrates. There was high temporal variation in species composition and abundance. The peak number of fish species occurred in August-October 2009, while the number of individual fish and biomass was highest during November 2009. Invertebrate numbers and biomass was highest in March, April, July and September 2009. Temporal changes in species abundance of fishes and invertebrates corresponded with changes in the shoot density and leaf length of the seagrass, Zostera marina.

  3. House and Stable Fly Seasonal Abundance, Larval Development Substrates, and Natural Parasitism on Small Equine Farms in Florida.

    PubMed

    Machtinger, E T; Leppla, N C; Hogsette, J A

    2016-08-01

    House flies, Musca domestica Linnaeus, and stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), are common pests on horse farms. The successful use of pupal parasitoids for management of these pests requires knowledge of seasonal fluctuations and biology of the flies as well as natural parasitism levels. However, these dynamics have not been investigated on small equine farms. A 1-year field study began in July 2010, in north central Florida, to determine adult fly population levels and breeding areas on four small equine farms. Weekly surveillance showed that pest flies were present year-round, though there were differences in adult population levels among farms and seasons. Fly development was not confirmed on two of the four small farms, suggesting that subtle differences in husbandry may adversely affect the development of immature flies. In six substrates previously identified as the most common among the farms, stable fly puparia were found overwhelmingly in hay mixed with equine manure and house fly puparia were found in fresh pine shavings mixed with equine manure. Natural parasitism was minimal as expected, but greatest numbers of natural parasitoids collected were of the genus Spalangia. Differences in adult and immature fly numbers recovered emphasizes the need for farm owners to confirm on-site fly development prior to purchase and release of biological control agents. Additionally, due to the low natural parasitism levels and domination of parasitism by Spalangia cameroni, augmentative releases using this species may be the most effective. PMID:26902468

  4. Formation and abundance of doubly-substituted methane isotopologues ( 13CH 3D) in natural gas systems

    NASA Astrophysics Data System (ADS)

    Ma, Qisheng; Wu, Sheng; Tang, Yongchun

    2008-11-01

    Formation of the Carbon-13 ( 13C) and deuterium (D) doubly-substituted methane isotopologues ( 13CH 3D) in natural gases is studied utilizing both first-principle quantum mechanism molecular calculation and direct FTIR laboratorial measurements of specifically synthesized high isotope concentration methane gas. For 13CH 3D, the symmetrically breathing mode A0 emerges as IR-detectable attributed to the molecular symmetry lowering to C3v from Td of the non-isotopic methane (CH 4), along with a large vibrational frequency shift from ˜3000 to ˜2250 cm -1. Our studies also indicate that the concentration of 13CH 3D is dependent on the environmental temperature through isotope exchanges among methane isotopologues; and the Gibbs' Free Energy difference due to Quantum Mechanics Zero-Point vibrational motions has the major contribution to this temperature dependency. Potential geologic applications of the 13CH 3D measurement to natural gas exploration and assessments are also discussed. In order to detect the 13CH 3D concentration change of each 50 °C in the natural gas system, a 10 -9 resolution is desirable. Such a measurement could provide important add-on information to distinguish natural gas origin and distribution.

  5. Renewable chemicals: dehydroxylation of glycerol and polyols.

    PubMed

    ten Dam, Jeroen; Hanefeld, Ulf

    2011-08-22

    The production of renewable chemicals is gaining attention over the past few years. The natural resources from which they can be derived in a sustainable way are most abundant in sugars, cellulose and hemicellulose. These highly functionalized molecules need to be de-functionalized in order to be feedstocks for the chemical industry. A fundamentally different approach to chemistry thus becomes necessary, since the traditionally employed oil-based chemicals normally lack functionality. This new chemical toolbox needs to be designed to guarantee the demands of future generations at a reasonable price. The surplus of functionality in sugars and glycerol consists of alcohol groups. To yield suitable renewable chemicals these natural products need to be defunctionalized by means of dehydroxylation. Here we review the possible approaches and evaluate them from a fundamental chemical aspect. PMID:21887771

  6. Renewable Chemicals: Dehydroxylation of Glycerol and Polyols

    PubMed Central

    ten Dam, Jeroen; Hanefeld, Ulf

    2011-01-01

    The production of renewable chemicals is gaining attention over the past few years. The natural resources from which they can be derived in a sustainable way are most abundant in sugars, cellulose and hemicellulose. These highly functionalized molecules need to be de-functionalized in order to be feedstocks for the chemical industry. A fundamentally different approach to chemistry thus becomes necessary, since the traditionally employed oil-based chemicals normally lack functionality. This new chemical toolbox needs to be designed to guarantee the demands of future generations at a reasonable price. The surplus of functionality in sugars and glycerol consists of alcohol groups. To yield suitable renewable chemicals these natural products need to be defunctionalized by means of dehydroxylation. Here we review the possible approaches and evaluate them from a fundamental chemical aspect. PMID:21887771

  7. Renewable energy: Renewing the environment

    SciTech Connect

    Noun, R.J.

    1996-12-31

    During the past 20 years, the United States has enacted some of the world`s most comprehensive legislation to protect and preserve its environmental heritage. These regulations have spawned a $115-billion-per-year industry for {open_quotes}green{close_quotes} products and services, with more than 35,000 companies providing jobs for American workers. On the other hand, environmental regulations have placed heavy cost burdens on many U.S. businesses as they struggle to remain competitive in both domestic and foreign markets. How, then, can one reconcile the growing need for environmental protection with the desire for a stronger, healthier economy? Even as Congress debates the value of existing environmental legislation, new threats are appearing on the horizon. For example, extensive storm damage from Hurricane Andrew and other natural disasters has prompted members of the $650-billion insurance industry to begin studying the effects that global warming may have on future property damage claims. More and more people are realizing that the most efficient and economical way to control pollution is to avoid creating it in the first place. And that`s where renewable energy comes in. Technologies based on nonpolluting renewable energy sources such as sunlight and wind can help preserve our environmental heritage without a tangled web of regulations to burden industry. Renewable energy technologies can also help the United States become a world leader in a potential $400-billion-a-year global market for environmentally friendly products.

  8. Dynamic nuclear polarization NMR enables the analysis of Sn-Beta zeolite prepared with natural abundance ¹¹⁹Sn precursors.

    PubMed

    Gunther, William R; Michaelis, Vladimir K; Caporini, Marc A; Griffin, Robert G; Román-Leshkov, Yuriy

    2014-04-30

    The catalytic activity of tin-containing zeolites, such as Sn-Beta, is critically dependent on the successful incorporation of the tin metal center into the zeolite framework. However, synchrotron-based techniques or solid-state nuclear magnetic resonance (ssNMR) of samples enriched with (119)Sn isotopes are the only reliable methods to verify framework incorporation. This work demonstrates, for the first time, the use of dynamic nuclear polarization (DNP) NMR for characterizing zeolites containing ~2 wt % of natural abundance Sn without the need for (119)Sn isotopic enrichment. The biradicals TOTAPOL, bTbK, bCTbK, and SPIROPOL functioned effectively as polarizing sources, and the solvent enabled proper transfer of spin polarization from the radical's unpaired electrons to the target nuclei. Using bCTbK led to an enhancement (ε) of 75, allowing the characterization of natural-abundance (119)Sn-Beta with excellent signal-to-noise ratios in <24 h. Without DNP, no (119)Sn resonances were detected after 10 days of continuous analysis. PMID:24697321

  9. Plant diversity moderates drought stress in grasslands: Implications from a large real-world study on (13)C natural abundances.

    PubMed

    Klaus, Valentin H; Hölzel, Norbert; Prati, Daniel; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Solly, Emily F; Hänsel, Falk; Fischer, Markus; Kleinebecker, Till

    2016-10-01

    Land-use change and intensification play a key role in the current biodiversity crisis. The resulting species loss can have severe effects on ecosystem functions and services, thereby increasing ecosystem vulnerability to climate change. We explored whether land-use intensification (i.e. fertilization intensity), plant diversity and other potentially confounding environmental factors may be significantly related to water use (i.e. drought stress) of grassland plants. Drought stress was assessed using δ(13)C abundances in aboveground plant biomass of 150 grassland plots across a gradient of land-use intensity. Under water shortage, plants are forced to increasingly take up the heavier (13)C due to closing stomata leading to an enrichment of (13)C in biomass. Plants were sampled at the community level and for single species, which belong to three different functional groups (one grass, one herb, two legumes). Results show that plant diversity was significantly related to the δ(13)C signal in community, grass and legume biomass indicating that drought stress was lower under higher diversity, although this relation was not significant for the herb species under study. Fertilization, in turn, mostly increased drought stress as indicated by more positive δ(13)C values. This effect was mostly indirect by decreasing plant diversity. In line with these results, we found similar patterns in the δ(13)C signal of the organic matter in the topsoil, indicating a long history of these processes. Our study provided strong indication for a positive biodiversity-ecosystem functioning relationship with reduced drought stress at higher plant diversity. However, it also underlined a negative reinforcing situation: as land-use intensification decreases plant diversity in grasslands, this might subsequently increases drought sensitivity. Vice-versa, enhancing plant diversity in species-poor agricultural grasslands may moderate negative effects of future climate change. PMID:27220098

  10. Determination of site-specific carbon isotope ratios at natural abundance by carbon-13 nuclear magnetic resonance spectroscopy.

    PubMed

    Caer, V; Trierweiler, M; Martin, G J; Martin, M L

    1991-10-15

    Site-specific natural isotope fractionation of hydrogen studied by deuterium NMR (SNIF-NMR) spectroscopy is a powerful source of information on hydrogen pathways occurring in biosyntheses in natural conditions. The potential of the carbon counterpart of this method has been investigated and compared. Three typical molecular species, ethanol, acetic acid, and vanillin, have been considered. Taking into account the requirements of quantitative 13C NMR, appropriate experimental procedures have been defined and the repeatability and reproducibility of the isotope ratio determinations have been checked in different conditions. It is shown that the carbon version of the SNIF-NMR method is capable of detecting small differences in the carbon-13 content of the ethyl fragment of ethanols from different botanical or synthetic origins. These results are in agreement with mass spectrometry determinations of the overall carbon isotope ratios. Deviations with respect to a statistical distribution of 13C have been detected in the case of acetic acid and vanillin. However, since the method is very sensitive to several kinds of systematic error, only a relative significance can be attached at present to the internal parameters directly accessible. Isotope dilution experiments have also been carried out in order to check the consistency of the results. In the present state of experimental accuracy, the 13C NMR method is of more limited potential than 2H SNIF-NMR spectroscopy. However it may provide complementary information. Moreover it is particularly efficient for detecting and quantifying adulterations that aim to mimic the overall carbon-13 content of a natural compound by adding a selectivity enriched species to a less expensive substrate from a different origin. PMID:1759714

  11. Supportive breeding boosts natural population abundance with minimal negative impacts on fitness of a wild population of Chinook salmon.

    PubMed

    Hess, Maureen A; Rabe, Craig D; Vogel, Jason L; Stephenson, Jeff J; Nelson, Doug D; Narum, Shawn R

    2012-11-01

    While supportive breeding programmes strive to minimize negative genetic impacts to populations, case studies have found evidence for reduced fitness of artificially produced individuals when they reproduce in the wild. Pedigrees of two complete generations were tracked with molecular markers to investigate differences in reproductive success (RS) of wild and hatchery-reared Chinook salmon spawning in the natural environment to address questions regarding the demographic and genetic impacts of supplementation to a natural population. Results show a demographic boost to the population from supplementation. On average, fish taken into the hatchery produced 4.7 times more adult offspring, and 1.3 times more adult grand-offspring than naturally reproducing fish. Of the wild and hatchery fish that successfully reproduced, we found no significant differences in RS between any comparisons, but hatchery-reared males typically had lower RS values than wild males. Mean relative reproductive success (RRS) for hatchery F(1) females and males was 1.11 (P = 0.84) and 0.89 (P = 0.56), respectively. RRS of hatchery-reared fish (H) that mated in the wild with either hatchery or wild-origin (W) fish was generally equivalent to W × W matings. Mean RRS of H × W and H × H matings was 1.07 (P = 0.92) and 0.94 (P = 0.95), respectively. We conclude that fish chosen for hatchery rearing did not have a detectable negative impact on the fitness of wild fish by mating with them for a single generation. Results suggest that supplementation following similar management practices (e.g. 100% local, wild-origin brood stock) can successfully boost population size with minimal impacts on the fitness of salmon in the wild. PMID:23025818

  12. Seasonal Abundance and Natural Inoculativity of Insect Vectors of Xylella fastidiosa in Oklahoma Tree Nurseries and Vineyards.

    PubMed

    Overall, Lisa M; Rebek, Eric J

    2015-12-01

    Xylella fastidiosa is the causative agent of diseases of perennial plants including peach, plum, elm, oak, pecan, and grape. This bacterial pathogen is transmitted by xylem-feeding insects. In recent years, Pierce's disease of grape has been detected in 10 counties in central and northeastern Oklahoma, prompting further investigation of the disease epidemiology in this state. We surveyed vineyards and tree nurseries in Oklahoma for potential insect vectors to determine species composition, infectivity, and natural inoculativity of commonly captured insect vectors. Yellow sticky cards were used to sample insect fauna at each location. Insects were removed from sticky cards and screened for X. fastidiosa using immunocapture-PCR to determine their infectivity. A second objective was to test the natural inoculativity of insect vectors that are found in vineyards. Graphocephala versuta (Say), Graphocephala coccinea (Forster), Paraulacizes irrorata (F.), Oncometopia orbona (F.), Cuerna costalis (F.), and Entylia carinata Germar were collected from vineyards and taken back to the lab to determine their natural inoculativity. Immunocapture-PCR was used to test plant and insect samples for presence of X. fastidiosa. The three most frequently captured species from vineyards and tree nurseries were G. versuta, Clastoptera xanthocephala Germar, and O. orbona. Of those insects screened for X. fastidiosa, 2.4% tested positive for the bacterium. Field-collected G. versuta were inoculative to both ragweed and alfalfa. Following a 7-d inoculation access period, a higher percentage of alfalfa became infected than ragweed. Results from this study provide insight into the epidemiology of X. fastidiosa in Oklahoma. PMID:26331482

  13. What's on the menu? Assessing microbial carbon sources and cycling in soils using natural abundance radiocarbon analysis

    NASA Astrophysics Data System (ADS)

    Mahmoudi, N.; Burns, L.; Mancini, S.; Fulthorpe, R.; Slater, G. F.

    2011-12-01

    Organic matter in soils is composed of diverse materials in various stages of decomposition. Soil organic matter is not in a single pool but rather in multiple carbon pools with different intrinsic turnover times that can be on annual to decadal and even millennial timescales. Microorganisms can influence the total amount of carbon stored in soils and the turnover rates of these different pools. However, the links between microbes and their ability to utilize these various carbon pools are not well understood. Moreover, microbes have been shown to co-utilize a number of available carbon sources rather than a single carbon source under soil conditions which creates difficulties in identifying microbial carbon sources in the natural environment. Compound-specific radiocarbon analysis of microbial phospholipid fatty acids (PLFA) has become a useful tool in elucidating microbial carbon sources in complex environments with multiple carbon sources. We investigated microbial carbon cycling at an industrial site in Ontario which included a variety of carbon sources including vegetation, PAHs and natural organic matter (NOM). Using this approach, the 14C content of microbial membrane lipids (which reflects their carbon source) can be compared to surrounding carbon sources in order to assess which carbon source they are metabolizing and incorporating into their lipids. In addition, we assessed microbial community structure and diversity by analyzing amplified bacterial, eukaryotic and archaeal rDNA fragments with denaturing gel gradient electrophoresis (DGGE). The Δ14C value for PLFAs ranged from +54 to -697% which indicates that microbial carbon sources across soils differ. The Δ14CPLFA for some soils is consistent with modern carbon sources while Δ14CPLFA for other soils is consistent with natural organic matter including older pools of carbon. The microbial communities at this site are not metabolizing PAHs but rather they are utilizing various pools of natural organic

  14. Energy Management Challenges and Opportunities with Increased Intermittent Renewable Generation on the California Electrical Grid

    NASA Astrophysics Data System (ADS)

    Eichman, Joshua David

    Renewable resources including wind, solar, geothermal, biomass, hydroelectric, wave and tidal, represent an opportunity for environmentally preferred generation of electricity that also increases energy security and independence. California is very proactive in encouraging the implementation of renewable energy in part through legislation like Assembly Bill 32 and the development and execution of Renewable Portfolio Standards (RPS); however renewable technologies are not without challenges. All renewable resources have some resource limitations, be that from location, capacity, cost or availability. Technologies like wind and solar are intermittent in nature but represent one of the most abundant resources for generating renewable electricity. If RPS goals are to be achieved high levels of intermittent renewables must be considered. This work explores the effects of high penetration of renewables on a grid system, with respect to resource availability and identifies the key challenges from the perspective of the grid to introducing these resources. The HiGRID tool was developed for this analysis because no other tool could explore grid operation, while maintaining system reliability, with a diverse set of renewable resources and a wide array of complementary technologies including: energy efficiency, demand response, energy storage technologies and electric transportation. This tool resolves the hourly operation of conventional generation resources (nuclear, coal, geothermal, natural gas and hydro). The resulting behavior from introducing additional renewable resources and the lifetime costs for each technology is analyzed.

  15. Determination of Natural 14C Abundances in Dissolved Organic Carbon in Organic-Rich Marine Sediment Porewaters by Thermal Sulfate Reduction

    NASA Astrophysics Data System (ADS)

    Johnson, L.; Komada, T.

    2010-12-01

    The abundances of natural 14C in dissolved organic carbon (DOC) in the marine environment hold clues regarding the processes that influence the biogeochemical cycling of this large carbon reservoir. At present, UV irradiation is the widely accepted method for oxidizing seawater DOC for determination of their 14C abundances. This technique yields precise and accurate values with low blanks, but it requires a dedicated vacuum line, and hence can be difficult to implement. As an alternative technique that can be conducted on a standard preparatory vacuum line, we modified and tested a thermal sulfate reduction method that was previously developed to determine δ13C values of marine DOC (Fry B. et al., 1996. Analysis of marine DOC using a dry combustion method. Mar. Chem., 54: 191-201.) to determine the 14C abundances of DOC in marine sediment porewaters. In this method, the sample is dried in a 100 ml round-bottom Pyrex flask in the presence of excess oxidant (K2SO4) and acid (H3PO4), and combusted at 550 deg.C. The combustion products are cryogenically processed to collect and quantify CO2 using standard procedures. Materials we have oxidized to date range from 6-24 ml in volume, and 95-1500 μgC in size. The oxidation efficiency of this method was tested by processing known amounts of reagent-grade dextrose and sucrose (as examples of labile organic matter), tannic acid and humic acid (as examples of complex natural organic matter), and porewater DOC extracted from organic-rich nearshore sediments. The carbon yields for all of these materials averaged 99±4% (n=18). The 14C abundances of standard materials IAEA C-6 and IAEA C-5 processed by this method using >1mgC aliquots were within error of certified values. The size and the isotopic value of the blank were determined by a standard dilution technique using IAEA C-6 and IAEA C-5 that ranged in size from 150 to 1500 μgC (n=4 and 2, respectively). This yielded a blank size of 6.7±0.7 μgC, and a blank isotopic

  16. Renewable smart materials

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Chan; Mun, Seongcheol; Ko, Hyun-U.; Zhai, Lindong; Kafy, Abdullahil; Kim, Jaehwan

    2016-07-01

    The use of renewable materials is essential in future technologies to harmonize with our living environment. Renewable materials can maintain our resources from the environment so as to overcome degradation of natural environmental services and diminished productivity. This paper reviews recent advancement of renewable materials for smart material applications, including wood, cellulose, chitin, lignin, and their sensors, actuators and energy storage applications. To further improve functionality of renewable materials, hybrid composites of inorganic functional materials are introduced by incorporating carbon nanotubes, titanium dioxide and tin oxide conducting polymers and ionic liquids. Since renewable materials have many advantages of biocompatible, sustainable, biodegradable, high mechanical strength and versatile modification behaviors, more research efforts need to be focused on the development of renewable smart materials.

  17. Natural hybrids in Atlantic eels (Anguilla anguilla, A. rostrata): evidence for successful reproduction and fluctuating abundance in space and time.

    PubMed

    Albert, Vicky; Jónsson, Bjarni; Bernatchez, Louis

    2006-06-01

    The outcome of natural hybridization is highly variable and depends on the nonexclusive effects of both pre- and post-mating reproductive barriers. The objective of this study was to address three specific questions regarding the dynamics of hybridization between the American and European eels (Anguilla rostrata and Anguilla anguilla). Using 373 AFLP loci, 1127 eels were genotyped, representing different life stages from both continents, as well as multiple Icelandic locations. We first evaluated the extent of hybridization and tested for the occurrence of hybrids beyond the first generation. Second, we tested whether hybrids were randomly distributed across continents and among Icelandic sampling sites. Third, we tested for a difference in the proportion of hybrids between glass eel and yellow eel stages in Iceland. Our results provided evidence for (i) an overall hybrid proportion of 15.5% in Iceland, with values ranging from 6.7% to 100% depending on life stages and locations; (ii) the existence of hybrids beyond the first generation; (iii) a nonrandom geographic distribution of hybrids in the North Atlantic; and (iv) a higher proportion of first and later generation hybrids in yellow eels compared to glass eels, as well as a significant latitudinal gradient in the proportion of hybrids in Icelandic freshwater. We propose that the combined effect of both differential survival of hybrids and variation in hybridization rate through time best explain these patterns. We discuss the possibility that climate change, which is impacting many environmental features in the North Atlantic, may have a determinant effect on the outcome of natural hybridization in Atlantic eels. PMID:16689906

  18. The perils and promises of microbial abundance: novel natures and model ecosystems, from artisanal cheese to alien seas.

    PubMed

    Paxson, Heather; Helmreich, Stefan

    2014-04-01

    Microbial life has been much in the news. From outbreaks of Escherichia coli to discussions of the benefits of raw and fermented foods to recent reports of life forms capable of living in extreme environments, the modest microbe has become a figure for thinking through the presents and possible futures of nature, writ large as well as small. Noting that dominant representations of microbial life have shifted from an idiom of peril to one of promise, we argue that microbes--especially when thriving as microbial communities--are being upheld as model ecosystems in a prescriptive sense, as tokens of how organisms and human ecological relations with them could, should, or might be. We do so in reference to two case studies: the regulatory politics of artisanal cheese and the speculative research of astrobiology. To think of and with microbial communities as model ecosystems offers a corrective to the scientific determinisms we detect in some recent calls to attend to the materiality of scientific objects. PMID:24941610

  19. 13C natural abundance in serum retinol acts as a biomarker for increases in dietary provitamin A.

    PubMed

    Howe, Julie A; Valentine, Ashley R; Hull, Angela K; Tanumihardjo, Sherry A

    2009-02-01

    The natural isotopic composition of 13C and 12C in tissues is largely determined by the diet. Sources of provitamin A carotenoids (e.g., vegetables) typically have a lower 13C to 12C ratio (13C:12C) than preformed vitamin A sources (i.e., dairy and meat) from corn-fed animals, which are prevalent in the US. The 13C:12C of serum retinol (13C:12C-retinol) was evaluated as a biomarker for vegetable intake in a 3-mo dietary intervention designed to promote weight-loss by increased vegetable consumption or reduced calorie and fat intake. Subjects were 21-50 y of age with a BMI between 30-40 kg/m2 and were enrolled from one geographic area in the US. The high vegetable group (n=20) was encouraged to increase daily vegetable and fruit consumption to 0.95 liter vegetables and 0.24-0.35 liter fruits. The caloric reduction group (n=17) was encouraged to lower caloric intake by 500 kcal and consume

  20. Effect of petroleum products on the decomposition of soil organic matter as assessed by 13C natural abundance

    NASA Astrophysics Data System (ADS)

    Stelmach, Wioleta; Szarlip, Paweł; Trembaczowski, Andrzej; Bieganowski, Andrzej

    2016-04-01

    Petroleum products are common contaminants in soils due to human activities. They are toxic for microorganisms and threat their functions, including decomposition of soil organic matter (SOM). The direct estimation of altered SOM decomposition - based on the CO2 emission - is impossible after oil contamination, because oil decomposition also contributes to the CO2 release. We used the natural differences in the isotopic signature (δ13C) of SOM and of oil products to partition the total CO2 for both sources and to analyze the suppression of SOM decomposition. The dynamics of 13C fractionation during the mineralization of gasoline and diesel was measured during 42 days. The 13C fractionation varied between -8.8‰ and +3.6‰ within the first 10 days, and stabilized thereafter at about -5.3‰ for gasoline and +3.2‰ for diesel. These 13C fractionations and δ13C values of CO2 emitted from the soil were used for correct partitioning of the total CO2. Contamination with gasoline reduced the CO2 efflux from SOM decomposition by a factor of 25 (from 151 to 6 mg C-CO2 kg‑1 soil during 42 days). The negative effect of diesel was much lower: the CO2 efflux from SOM was decreased by less than a factor of 2. The strong effect of gasoline versus diesel reflects the lower absorption of gasoline to mineral particles and the development of a thin film on water surfaces, leading to toxicity for microorganisms. We conclude that the small differences of 13C of SOM and of organic pollutants can be used to partition CO2 fluxes and analyze pollutant effects on SOM decomposition.

  1. Evidence of 13C non-covalent isotope effects obtained by quantitative 13C nuclear magnetic resonance spectroscopy at natural abundance during normal phase liquid chromatography.

    PubMed

    Botosoa, Eliot P; Silvestre, Virginie; Robins, Richard J; Rojas, Jose Manuel Moreno; Guillou, Claude; Remaud, Gérald S

    2009-10-16

    Quantitative isotopic (13)C NMR at natural abundance has been used to determine the site-by-site (13)C/(12)C ratios in vanillin and a number of related compounds eluted from silica gel chromatography columns under similar conditions. Head-to-tail isotope fractionation is observed in all compounds at the majority of carbon positions. Furthermore, the site-specific isotope deviations show signatures characteristic of the position and functionality of the substituents present. The observed effects are more complex than would be obtained by simply summing the individual effects. Such detail is hidden when only the global (13)C content is measured by mass spectrometry. In particular, carbon positions within the aromatic ring are found to show site-specific isotope fractionation between the solute and the stationary phase. These interactions, defined as non-covalent isotope effects, can be normal or inverse and vary with the substitution pattern present. PMID:19748628

  2. Application of (119)Sn CPMG MAS NMR for Fast Characterization of Sn Sites in Zeolites with Natural (119)Sn Isotope Abundance.

    PubMed

    Kolyagin, Yury G; Yakimov, Alexander V; Tolborg, Søren; Vennestrøm, Peter N R; Ivanova, Irina I

    2016-04-01

    (119)Sn CPMG MAS NMR is demonstrated to be a fast and efficient method for characterization of Sn-sites in Sn-containing zeolites. Tuning of the CPMG echo-train sequence decreases the experimental time by a factor of 5-40 in the case of as-synthesized and hydrated Sn-BEA samples and by 3 orders of magnitude in the case of dehydrated Sn-BEA samples as compared to conventional methods. In the latter case, the reconstruction of the quantitative spectrum without the loss of sensitivity is shown to be possible. The method proposed allows obtaining (119)Sn MAS NMR spectra with improved resolution for Sn-BEA zeolites with natural (119)Sn isotope abundance using conventional MAS NMR equipment. PMID:26978430

  3. 13C Natural Abundance in Serum Retinol Acts as a Biomarker for Increases in Dietary Provitamin A

    PubMed Central

    Howe, Julie A; Valentine, Ashley R; Hull, Angela K; Tanumihardjo, Sherry A

    2009-01-01

    The natural isotopic composition of 13C and 12C in tissues is largely determined by the diet. Sources of provitamin A carotenoids (e.g., vegetables) typically have a lower 13C to 12C ratio (13C:12C) than preformed vitamin A sources (i.e., dairy and meat) from corn-fed animals, which are prevalent in the US. The 13C:12C of serum retinol (13C:12C-retinol) was evaluated as a biomarker for vegetable intake in a 3-mo dietary intervention designed to promote weight-loss by increased vegetable consumption or reduced calorie and fat intake. Subjects were 21–50 y of age with a BMI between 30–40 kg/m2 and were enrolled from one geographic area in the US. The high vegetable group (n = 20) was encouraged to increase daily vegetable and fruit consumption to 0.95 liter vegetables and 0.24–0.35 liter fruits. The caloric reduction group (n = 17) was encouraged to lower caloric intake by 500 kcal and consume ≤25% kcal from fat daily. Provided meals supplied 75–100% vegetable and fruit goals and 50–67% kcal and fat g per day. Carotenoid supplementation was discontinued by subjects during the study. Serum retinol and provitamin A carotenoid concentrations; intake of preformed vitamin A, provitamin A, and fat; and body weight, fat mass, and lean mass were analyzed for correlations to 13C:12C-retinol. 13C:12C-Retinol decreased in the vegetable group after intervention (P = 0.050) and the correlation with provitamin A intake was approaching significance (P = 0.079). 13C:12C-Retinol did not change in the caloric reduction group (P = 0.43). 13C:12C-Retinol changes with the vitamin A source in the diet and can be used as a biomarker for increases in dietary provitamin A vegetable intake. PMID:19116317

  4. Changes in Natural Abundance Carbon Stable isotopes of Human Blood and Saliva After 24 Days of Controlled Carbohydrate Supplementation

    NASA Astrophysics Data System (ADS)

    Kraft, R. A.; Jahren, A. H.; Baer, D. J.; Caballero, B.

    2008-12-01

    the δ13C value of their blood and saliva relative to baseline: blood clot was enriched by 0.27‰; blood serum by 0.50‰ and saliva by 1.12‰. We believe this overall enrichment resulted from a 13C-enriched bulk diet (δ13C = - 20.42‰) relative to the subjects free-living diet. Evidence for this derives from inspection of foods within the bulk diet provided, compared to published profiles of the typical American diet. We will discuss possible complicating factors, such as differential absorption and metabolism of the supplements according to solubility and caloric value. These results are encouraging for the development of a δ13C blood serum biomarker that, in the company of other tests, could be used to indicate a change in carbohydrate intake. Bray, G.A., Nielsen, S.J. and Popkin, B.M., 2004. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. American Journal of Clinical Nutrition, 79: 537-543. Havel, P.J., 2005. Dietary fructose: Implications for dysregulation of energy homeostasis and lipid/carbohydrate metabolism. Nutrition Reviews, 63(5): 133-157. Tilman D., 1998. The greening of the green revolution. Nature, 396:211-212.

  5. Position-Specific Isotope Analysis of Xanthines: A (13)C Nuclear Magnetic Resonance Method to Determine the (13)C Intramolecular Composition at Natural Abundance.

    PubMed

    Diomande, Didier G; Martineau, Estelle; Gilbert, Alexis; Nun, Pierrick; Murata, Ariaki; Yamada, Keita; Watanabe, Naoharu; Tea, Illa; Robins, Richard J; Yoshida, Naohiro; Remaud, Gérald S

    2015-07-01

    The natural xanthines caffeine, theobromine, and theophylline are of major commercial importance as flavor constituents in coffee, cocoa, tea, and a number of other beverages. However, their exploitation for authenticity, a requirement in these commodities that have a large origin-based price-range, by the standard method of isotope ratio monitoring by mass spectrometry (irm-MS) is limited. We have now developed a methodology that overcomes this deficit that exploits the power of isotopic quantitative (13)C nuclear magnetic resonance (NMR) spectrometry combined with chemical modification of the xanthines to enable the determination of positional intramolecular (13)C/(12)C ratios (δ(13)Ci) with high precision. However, only caffeine is amenable to analysis: theobromine and theophylline present substantial difficulties due to their poor solubility. However, their N-methylation to caffeine makes spectral acquisition feasible. The method is confirmed as robust, with good repeatability of the δ(13)Ci values in caffeine appropriate for isotope fractionation measurements at natural abundance. It is shown that there is negligible isotope fractionation during the chemical N-methylation procedure. Thus, the method preserves the original positional δ(13)Ci values. The method has been applied to measure the position-specific variation of the (13)C/(12)C distribution in caffeine. Not only is a clear difference between caffeine isolated from different sources observed, but theobromine from cocoa is found to show a (13)C pattern distinct from that of caffeine. PMID:26067163

  6. GIS-based approach for optimal siting and sizing of renewables considering techno-environmental constraints and the stochastic nature of meteorological inputs

    NASA Astrophysics Data System (ADS)

    Daskalou, Olympia; Karanastasi, Maria; Markonis, Yannis; Dimitriadis, Panayiotis; Koukouvinos, Antonis; Efstratiadis, Andreas; Koutsoyiannis, Demetris

    2016-04-01

    Following the legislative EU targets and taking advantage of its high renewable energy potential, Greece can obtain significant benefits from developing its water, solar and wind energy resources. In this context we present a GIS-based methodology for the optimal sizing and siting of solar and wind energy systems at the regional scale, which is tested in the Prefecture of Thessaly. First, we assess the wind and solar potential, taking into account the stochastic nature of the associated meteorological processes (i.e. wind speed and solar radiation, respectively), which is essential component for both planning (i.e., type selection and sizing of photovoltaic panels and wind turbines) and management purposes (i.e., real-time operation of the system). For the optimal siting, we assess the efficiency and economic performance of the energy system, also accounting for a number of constraints, associated with topographic limitations (e.g., terrain slope, proximity to road and electricity grid network, etc.), the environmental legislation and other land use constraints. Based on this analysis, we investigate favorable alternatives using technical, environmental as well as financial criteria. The final outcome is GIS maps that depict the available energy potential and the optimal layout for photovoltaic panels and wind turbines over the study area. We also consider a hypothetical scenario of future development of the study area, in which we assume the combined operation of the above renewables with major hydroelectric dams and pumped-storage facilities, thus providing a unique hybrid renewable system, extended at the regional scale.

  7. Molecular Investigation of the Short-term Sequestration of Natural Abundance 13C -labelled Cow Dung in the Surface Horizons of a Temperate Grassland Soil

    NASA Astrophysics Data System (ADS)

    Dungait, J.; Bol, R.; Evershed, R. P.

    2004-12-01

    An adequate understanding of the carbon (C) sequestration potential of grasslands requires that the quantity and residence times of C inputs be measured. Herbivore dung is largely comprised of plant cell wall material, a significant source of stable C in intensively grazed temperate grassland ecosystems that contributes to the soil carbon budget. Our work uses compound-specific isotope analysis to identify the pattern of input of dung-derived compounds from natural abundance 13C/-labelled cow dung into the surface horizons of a temperate grassland soil over one year. C4 dung (δ 13C \\-12.6 ‰ ) from maize fed cows was applied to a temperate grassland surface (δ 13C \\-29.95 ‰ ) at IGER-North Wyke (Devon, UK), and dung remains and soil cores beneath the treatments collected at ŧ = 7, 14, 28, 56, 112, 224 and 372 days. Bulk dung carbon present in the 0\\-1 cm and 1\\-5 cm surface horizons of a grassland soil over one year was estimated using Δ 13C between C4 dung and C3 dung, after Bol {\\et al.} (2000). The major biochemical components of dung were quantified using proximate forage fibre analyses, after Goering and Van Soest (1970) and identified using `wet' chemical and GC-MS methods. Plant cell wall polysaccharides and lignin were found to account for up to 67 {%} of dung dry matter. Hydrolysed polysaccharides were prepared as alditol acetates for analyses (after Docherty {\\et al.}, 2001), and a novel application of an off-line pyrolysis method applied to measure lignin-derived phenolic compounds (after Poole & van Bergen, 2002). This paper focuses on major events in the incorporation of dung carbon, estimated using natural abundance 13C&-slash;labelling technique. This revealed a major bulk input of dung carbon after a period of significant rainfall with a consequent decline in bulk soil δ 13C values until the end of the experiment (Dungait {\\et al.}, submitted). Findings will be presented revealing contribution of plant cell wall polysaccharides and

  8. Investigation of Solute-Fiber Affinity and Orientational Ordering of Norbornadiene Interacting with Two-Polypeptide Chiral Liquid Crystalline Solvents by Natural Abundance Deuterium (NAD) NMR.

    PubMed

    Serhan, Zeinab; Aroulanda, Christie; Lesot, Philippe

    2016-08-01

    A prochiral bridged compound of C2v symmetry, the norbornadiene (NBD), oriented in a chiral liquid crystal composed of various mixtures of poly-γ-benzyl-l-glutamate (PBLG) and poly-ε-carboxy-l-lysine (PCBLL), two chiral homopolypeptides, is investigated using natural abundance deuterium 2D-NMR (NAD 2D-NMR) spectroscopy. In such chiral oriented solvents, enantiotopic directions are spectrally nonequivalent, and two distinct (2)H quadrupolar doublets associated with enantioisotopomeric pairs of NBD are detected. As the two homopolypeptides have the same absolute configuration but distinct chemical functions in their side chains, the variation of residual quadrupolar couplings (RQC's) allows the determination of the relative solute-fiber affinities toward the two polypeptides in these lyotropic bipolymeric systems. Besides the experimental measurement of RQC's and the determination of their signs at each inequivalent (2)H site, the elements of the second-rank order tensor, Sαβ, are calculated by assuming a modeled structure. The variations of RQC's and diagonalized order parameters, Sα'α', are followed versus the relative proportion of two polypeptides in the chiral oriented mixture. The influence of the solute mass fraction in the two-homopolypeptide oriented samples is also examined as well as the case of homogeneous and uniform achiral mesophases "PBG-PCBL" made of two pairs of mirror-image homopolypeptides (PBLG/PBDG and PCBLL/PCBDL). In the latter, the solute ordering is modulated by the proportion of each type of homopolypeptide (chemical nature and absolute configuration), leading to eliminate the enantiodiscrimination mechanisms on the average. In the frame of a model, new insights on the solute-homopolypeptide fiber interactions are discussed. PMID:27383731

  9. Natural abundance 17O, 6Li NMR and molecular modeling studies of the solvation structures of lithium bis(fluorosulfonyl)imide/1,2-dimethoxyethane liquid electrolytes

    NASA Astrophysics Data System (ADS)

    Wan, Chuan; Hu, Mary Y.; Borodin, Oleg; Qian, Jiangfeng; Qin, Zhaohai; Zhang, Ji-Guang; Hu, Jian Zhi

    2016-03-01

    Natural abundance 17O and 6Li NMR experiments, quantum chemistry and molecular dynamics studies were employed to investigate the solvation structures of Li+ at various concentrations of LiFSI in DME electrolytes. It was found that the chemical shifts of both 17O and 6Li changed with the concentration of LiFSI, indicating the changes of solvation structures with concentration. For the quantum chemistry calculations, the coordinated cluster LiFSI(DME)2 forms at first, and its relative ratio increases with increasing LiFSI concentration to 1 M. Then the solvation structure LiFSI(DME) become the dominant component. As a result, the coordination of forming contact ion pairs between Li+ and FSI- ion increases, but the association between Li+ and DME molecule decreases. Furthermore, at LiFSI concentration of 4 M the solvation structures associated with Li+(FSI-)2(DME), Li+2(FSI-)(DME)4 and (LiFSI)2(DME)3 become the dominant components. For the molecular dynamics simulation, with increasing concentration, the association between DME and Li+ decreases, and the coordinated number of FSI- increases, which is in perfect accord with the DFT results.

  10. Consistency of NMR and mass spectrometry determinations of natural-abundance site-specific carbon isotope ratios. The case of glycerol.

    PubMed

    Zhang, B L; Trierweiler, M; Jouitteau, C; Martin, G J

    1999-07-01

    Quantitative determinations of natural-abundance carbon isotope ratios by nuclear magnetic resonance (SNIF-NMR) have been optimized by appropriate selection of the experimental conditions and by signal analysis based on a dedicated algorithm. To check the consistency of the isotopic values obtained by NMR and mass spectrometry (IRMS) the same glycerol samples have been investigated by both techniques. To have access to site-specific isotope ratios by IRMS, the products have been degraded and transformed into two derivatives, one of which contains carbons 1 and 3 and the other carbon 2 of glycerol. The sensitivity of the isotopic parameters determined by IRMS to fractionation effects possibly occurring in the course of the chemical transformations has been investigated, and the repeatability and reproducibility of both analytical chains have been estimated. The good agreement observed between the two series of isotopic results supports the reliability of the two different approaches. SNIF-NMR is therefore a very attractive tool for routine determination, in a single nondestructive experiment, of the carbon isotope distribution in glycerol, and the method can be applied to other compounds. Using this method, the isotopic distributions have been compared for glycerol samples, obtained from plant or animal oils, extracted from fermented media, or prepared by chemical synthesis. Typical behaviors are characterized. PMID:21662780

  11. A Computational Framework for High-Throughput Isotopic Natural Abundance Correction of Omics-Level Ultra-High Resolution FT-MS Datasets

    PubMed Central

    Carreer, William J.; Flight, Robert M.; Moseley, Hunter N. B.

    2013-01-01

    New metabolomics applications of ultra-high resolution and accuracy mass spectrometry can provide thousands of detectable isotopologues, with the number of potentially detectable isotopologues increasing exponentially with the number of stable isotopes used in newer isotope tracing methods like stable isotope-resolved metabolomics (SIRM) experiments. This huge increase in usable data requires software capable of correcting the large number of isotopologue peaks resulting from SIRM experiments in a timely manner. We describe the design of a new algorithm and software system capable of handling these high volumes of data, while including quality control methods for maintaining data quality. We validate this new algorithm against a previous single isotope correction algorithm in a two-step cross-validation. Next, we demonstrate the algorithm and correct for the effects of natural abundance for both 13C and 15N isotopes on a set of raw isotopologue intensities of UDP-N-acetyl-D-glucosamine derived from a 13C/15N-tracing experiment. Finally, we demonstrate the algorithm on a full omics-level dataset. PMID:24404440

  12. Nitrogen input 15N-signatures are reflected in plant 15N natural abundances of N-rich tropical forest in China

    NASA Astrophysics Data System (ADS)

    Abdisa Gurmesa, Geshere; Lu, Xiankai; Gundersen, Per; Yunting, Fang; Mo, Jiangming

    2016-04-01

    In this study, we tested the measurement of natural abundance of 15N (δ15N) for its ability to assess changes in N cycling due to increased N deposition in two forest types; namely, an old-growth broadleaved forest and a pine forest, in southern China. We measured δ15N values of inorganic N in input and output fluxes under ambient N deposition, and N concentration and δ15N of major ecosystem compartments under ambient and increased N deposition. Our results showed that N deposition to the forests was 15N-depleted, and was dominated by NH4-N. Plants were 15N-depleted due to imprint from the 15N-depleted atmospheric N deposition. The old-growth forest had larger N concentration and was more 15N-enriched than the pine forest. Nitrogen addition did not significantly affect N concentration, but it significantly increased δ15N values of plants, and slightly more so in the pine forest, toward the 15N signature of the added N in both forests. The result indicates that the pine forest may rely more on the 15N-depleted deposition N. Soil δ15N values were slightly decreased by the N addition. Our result suggests that ecosystem δ15N is more sensitive to the changes in ecosystem N status and N cycling than N concentration in N-saturated sub-tropical forests.

  13. The physical state of osmoregulatory solutes in unicellular algae. A natural-abundance carbon-13 nuclear-magnetic-resonance relaxation study.

    PubMed Central

    Norton, R S; MacKay, M A; Borowitzka, L J

    1982-01-01

    Natural-abundance 13C n.m.r. spin-lattice relaxation-time measurements have been carried out on intact cells of the unicellular blue--green alga Synechococcus sp. and the unicellular green alga Dunaliella salina, with the aim of characterizing the environments of the organic osmoregulatory solutes in these salt-tolerant organisms. In Synechococcus sp., all of the major organic osmoregulatory solute, 2-O-alpha-D-glucopyranosylglycerol, is visible in spectra of intact cells. Its rotational motion in the cell is slower by a factor of approx. 2.4 than in aqueous solution, but the molecule is still freely mobile and therefore able to contribute to the osmotic balance. In D. salina, only about 60% of the osmoregulatory solute glycerol is visible in spectra of intact cells. The rotational mobility of this observable fraction is approximately half that found in aqueous solution, but the data also indicate that there is a significant concentration of some paramagnetic species in D. salina which contributes to the overall spin-lattice relaxation of the glycerol carbon atoms. The non-observable fraction, which must correspond to glycerol molecules that have very broad 13C resonances and that are in slow exchange with bulk glycerol, has not been properly characterized as yet, but may represent glycerol in the chloroplast. The implications of these findings in relation to the physical state of the cytoplasm and the mechanism of osmoregulation in these cells are discussed. PMID:6807296

  14. Nitrogen content, 15N natural abundance and biomass of the two pleurocarpous mosses Pleurozium schreberi (Brid.) Mitt. and Scleropodium purum (Hedw.) Limpr. in relation to atmospheric nitrogen deposition.

    PubMed

    Solga, A; Burkhardt, J; Zechmeister, H G; Frahm, J-P

    2005-04-01

    The suitability of the two pleurocarpous mosses Pleurozium schreberi and Scleropodium purum for assessing spatial variation in nitrogen deposition was investigated. Sampling was carried out at eight sites in the western part of Germany with bulk deposition rates ranging between 6.5 and 18.5 kg N ha(-1) yr(-1). In addition to the effect of deposition on the nitrogen content of the two species, its influence on 15N natural abundance (delta15N values) and on productivity was examined. Annual increases of the mosses were used for all analyses. Significant relationships between bulk N deposition and nitrogen content were obtained for both species; delta15N-values reflected the ratio of NH4-N to NO3-N in deposition. A negative effect of nitrogen input on productivity, i.e. decreasing biomass per area with increasing N deposition due to a reduction of stem density, was particularly evident with P. schreberi. Monitoring of N deposition by means of mosses is considered an important supplement to existing monitoring programs. It makes possible an improved spatial resolution, and thus those areas that receive high loads of nitrogen are more easily discernible. PMID:15620592

  15. Studies of individual carbon sites of proteins in solution by natural abundance carbon 13 nuclear magnetic resonance spectroscopy. Strategies for assignments.

    PubMed

    Oldfield, E; Norton, R S; Allerhand, A

    1975-08-25

    Natural abundance 13C Fourier transform NMR spectra (at 15.18 MHz, in 20-mm sample tubes) of aqueous native proteins yield numerous narrow single carbon resonances of nonprotonated aromatic carbons. Techniques for the assignment of these resonances are presented. Each technique is applied to one or more of the following proteins: ferricytochrome c from horse heart and Candida krusei, ferrocytochrome c and cyanoferricytochrome c from horse heart, lysozyme from hen egg white, cyanoferrimyoglobins from horse and sperm whale skeletal muscle, and carbon monoxide myoglobin from horse. In all of the protein spectra we have examined, methine aromatic carbons give rise to broad bands. Studies of the narrow resonances of nonprotonated aromatic carbons of proteins are facilitated by removal of these broad bands by means of the convolution-difference method, preferably from spectra recorded under conditions of noise-modulated off-resonance proton decoupling. We present a summary of the chemical shift ranges for the various types of nonprotonated aromatic carbons of amino acid residues and hemes of diamagnetic proteins, based on our results for hen egg white lysozyme, horse heart ferrocytochrome c, horse carbon monoxide myoglobin, and carbon monoxide hemoglobins from various species... PMID:169240

  16. The use of natural abundance carbon-13 to identify and quantify sources of emitted carbon dioxide in a calcareous southern Ontario Luvisolic soil

    NASA Astrophysics Data System (ADS)

    Wilton, Meaghan

    Three studies Were conducted at the Elora Research Station (ERS) on a Luvisolic soil to investigate the soil inorganic carbon (SIC) and soil organic carbon (SOC) components contributing to the CO2 flux (FC) using natural 13C abundance. SIC contributed to the FC in intact soil incubations. Soil disruption exacerbated the release of CO2 from both pedogenic and lithogenic carbonates. Field and laboratory techniques to obtain the delta13C of respired CO2 (delta13CR) were compared. Short-term deployment of non flow-through non steady-state chambers and the use of the simple two-ended mass balance approach to derive delta 13CR were found acceptable to apply to the ERS site. The delta13CR from a corn field at ERS with a history of multiple C4 and C3 crop rotations was partitioned into SIC and SOC components using two approaches. Root respiration contributed 2% - 64% and carbonates contribute up to 20% to the FC.

  17. Natural (15)N Abundance in Key Amino Acids from Lamb Muscle: Exploring a New Horizon in Diet Authentication and Assessment of Feed Efficiency in Ruminants.

    PubMed

    Cantalapiedra-Hijar, Gonzalo; Ortigues-Marty, Isabelle; Schiphorst, Anne-Marie; Robins, Richard J; Tea, Illa; Prache, Sophie

    2016-05-25

    Natural (15)N abundance (δ(15)N) varies between individual amino acids (AAs). We hypothesized that δ(15)N of nontransaminating and essential AAs ("source" AAs, such as phenylalanine) present in animal tissues could be used as a marker of dietary origin, whereas δ(15)N of transaminating AAs ("trophic" AAs, such as glutamic acid) could give more detailed insights into animal feed efficiency. Two diets based on dehydrated Lucerne pellets were tested in growing lambs, which promoted different feed efficiencies. No dietary effects were noted on δ(15)N of any AAs analyzed in lamb muscle. In addition, δ(15)N of phenylalanine was unexpectedly similar to that of glutamic acid, suggesting that δ(15)N of AAs is significantly derived from the metabolism of the rumen microbiota and, thus, are not suited for diet authentication in ruminants. In contrast, the δ(15)N of transaminating AAs facilitates an improved prediction of animal feed efficiency compared to the classical isotopic bulk N analysis. PMID:27148901

  18. A New Tool for NMR Crystallography: Complete (13)C/(15)N Assignment of Organic Molecules at Natural Isotopic Abundance Using DNP-Enhanced Solid-State NMR.

    PubMed

    Märker, Katharina; Pingret, Morgane; Mouesca, Jean-Marie; Gasparutto, Didier; Hediger, Sabine; De Paëpe, Gaël

    2015-11-01

    NMR crystallography of organic molecules at natural isotopic abundance (NA) strongly relies on the comparison of assigned experimental and computed NMR chemical shifts. However, a broad applicability of this approach is often hampered by the still limited (1)H resolution and/or difficulties in assigning (13)C and (15)N resonances without the use of structure-based chemical shift calculations. As shown here, such difficulties can be overcome by (13)C-(13)C and for the first time (15)N-(13)C correlation experiments, recorded with the help of dynamic nuclear polarization. We present the complete de novo (13)C and (15)N resonance assignment at NA of a self-assembled 2'-deoxyguanosine derivative presenting two different molecules in the asymmetric crystallographic unit cell. This de novo assignment method is exclusively based on aforementioned correlation spectra and is an important addition to the NMR crystallography approach, rendering firstly (1)H assignment straightforward, and being secondly a prerequisite for distance measurements with solid-state NMR. PMID:26485326

  19. An optimal renewable energy mix for Indonesia

    NASA Astrophysics Data System (ADS)

    Leduc, Sylvain; Patrizio, Piera; Yowargana, Ping; Kraxner, Florian

    2016-04-01

    Indonesia has experienced a constant increase of the use of petroleum and coal in the power sector, while the share of renewable sources has remained stable at 6% of the total energy production during the last decade. As its domestic energy demand undeniably continues to grow, Indonesia is committed to increase the production of renewable energy. Mainly to decrease its dependency on fossil fuel-based resources, and to decrease the anthropogenic emissions, the government of Indonesia has established a 23 percent target for renewable energy by 2025, along with a 100 percent electrification target by 2020 (the current rate is 80.4 percent). In that respect, Indonesia has abundant resources to meet these targets, but there is - inter alia - a lack of proper integrated planning, regulatory support, investment, distribution in remote areas of the Archipelago, and missing data to back the planning. To support the government of Indonesia in its sustainable energy system planning, a geographic explicit energy modeling approach is applied. This approach is based on the energy systems optimization model BeWhere, which identifies the optimal location of energy conversion sites based on the minimization of the costs of the supply chain. The model will incorporate the existing fossil fuel-based infrastructures, and evaluate the optimal costs, potentials and locations for the development of renewable energy technologies (i.e., wind, solar, hydro, biomass and geothermal based technologies), as well as the development of biomass co-firing in existing coal plants. With the help of the model, an optimally adapted renewable energy mix - vis-à-vis the competing fossil fuel based resources and applicable policies in order to promote the development of those renewable energy technologies - will be identified. The development of the optimal renewable energy technologies is carried out with special focus on nature protection and cultural heritage areas, where feedstock (e.g., biomass

  20. [Institutional Renewal].

    ERIC Educational Resources Information Center

    Brown, Peggy, Ed.

    1983-01-01

    The theme of this journal issue is "Institutional Renewal." Projects designed to address the issues of the 1980s at 18 colleges are described, and 15 definitions of institutional renewal are presented. Participating colleges were provided expert advice through the Association of American College's (AAC) Project Lodestar (renamed Consultation and…

  1. The effect of drought and interspecific interactions on depth of water uptake in deep- and shallow-rooting grassland species as determined by δ18O natural abundance

    NASA Astrophysics Data System (ADS)

    Hoekstra, N. J.; Finn, J. A.; Hofer, D.; Lüscher, A.

    2014-08-01

    Increased incidence of drought, as predicted under climate change, has the potential to negatively affect grassland production. Compared to monocultures, vertical belowground niche complementarity between shallow- and deep-rooting species may be an important mechanism resulting in higher yields and higher resistance to drought in grassland mixtures. However, very little is known about the belowground responses in grassland systems and increased insight into these processes may yield important information both to predict the effect of future climate change and better design agricultural systems to cope with this. This study assessed the effect of a 9-week experimental summer drought on the depth of water uptake of two shallow-rooting species (Lolium perenne L. and Trifolium repens L.) and two deep-rooting species (Cichorium intybus L. and Trifolium pratense L.) in grassland monocultures and four-species mixtures by using the natural abundance δ18O isotope method. We tested the following three hypotheses: (1) drought results in a shift of water uptake to deeper soil layers, (2) deep-rooting species take up a higher proportion of water from deeper soil layers relative to shallow-rooting species, and (3) as a result of interspecific interactions in mixtures, the water uptake of shallow-rooting species becomes shallower when grown together with deep-rooting species and vice versa, resulting in reduced niche overlap. The natural abundance δ18O technique provided novel insights into the depth of water uptake of deep- and shallow- rooting grassland species and revealed large shifts in depth of water uptake in response to drought and interspecific interactions. Compared to control conditions, drought reduced the proportional water uptake from 0-10 cm soil depth (PCWU0-10) of L. perenne, T. repens and C. intybus in monocultures by on average 54%. In contrast, the PCWU0-10 of T. pratense in monoculture increased by 44%, and only when grown in mixture did the PCWU0-10 of T

  2. Contribution of oil and natural gas production to renewed increase of atmospheric methane (2007-2014): top-down estimate from ethane and methane column observations

    NASA Astrophysics Data System (ADS)

    Hausmann, P.; Sussmann, R.; Smale, D.

    2015-12-01

    Harmonized time series of column-averaged mole fractions of atmospheric methane and ethane over the period 1999-2014 are derived from solar Fourier transform infrared (FTIR) measurements at the Zugspitze summit (47° N, 2964 m a.s.l.) and at Lauder (45° S, 370 m a.s.l.). Long-term trend analysis reveals a consistent renewed methane increase since 2007 of 6.2 [5.6, 6.9] ppb yr-1 at the Zugspitze and 6.0 [5.3, 6.7] ppb yr-1 at Lauder (95 % confidence intervals). Several recent studies provide pieces of evidence that the renewed methane increase is most likely driven by two main factors: (i) increased methane emissions from tropical wetlands, followed by (ii) increased thermogenic methane emissions due to growing oil and natural gas production. Here, we quantify the magnitude of the second class of sources, using long-term measurements of atmospheric ethane as tracer for thermogenic methane emissions. In 2007, after years of weak decline, the Zugspitze ethane time series shows the sudden onset of a significant positive trend (2.3 [1.8, 2.8] × 10-2 ppb yr-1 for 2007-2014), while a negative trend persists at Lauder after 2007 (-0.4 [-0.6, -0.1] × 10-2 ppb yr-1). Zugspitze methane and ethane time series are significantly correlated for the period 2007-2014 and can be assigned to thermogenic methane emissions with an ethane-to-methane ratio of 10-21 %. We present optimized emission scenarios for 2007-2014 derived from an atmospheric two-box model. From our trend observations we infer a total ethane emission increase over the period 2007-2014 from oil and natural gas sources of 1-11 Tg yr-1 along with an overall methane emission increase of 24-45 Tg yr-1. Based on these results, the oil and natural gas emission contribution C to the renewed methane increase is deduced using three different emission scenarios with dedicated ranges of methane-to-ethane ratios (MER). Reference scenario 1 assumes an oil and gas emission combination with MER = 3.3-7.6, which results in a

  3. Contribution of oil and natural gas production to renewed increase in atmospheric methane (2007-2014): top-down estimate from ethane and methane column observations

    NASA Astrophysics Data System (ADS)

    Hausmann, Petra; Sussmann, Ralf; Smale, Dan

    2016-03-01

    Harmonized time series of column-averaged mole fractions of atmospheric methane and ethane over the period 1999-2014 are derived from solar Fourier transform infrared (FTIR) measurements at the Zugspitze summit (47° N, 11° E; 2964 m a.s.l.) and at Lauder (45° S, 170° E; 370 m a.s.l.). Long-term trend analysis reveals a consistent renewed methane increase since 2007 of 6.2 [5.6, 6.9] ppb yr-1 (parts-per-billion per year) at the Zugspitze and 6.0 [5.3, 6.7] ppb yr-1 at Lauder (95 % confidence intervals). Several recent studies provide pieces of evidence that the renewed methane increase is most likely driven by two main factors: (i) increased methane emissions from tropical wetlands, followed by (ii) increased thermogenic methane emissions due to growing oil and natural gas production. Here, we quantify the magnitude of the second class of sources, using long-term measurements of atmospheric ethane as a tracer for thermogenic methane emissions. In 2007, after years of weak decline, the Zugspitze ethane time series shows the sudden onset of a significant positive trend (2.3 [1.8, 2.8] × 10-2 ppb yr-1 for 2007-2014), while a negative trend persists at Lauder after 2007 (-0.4 [-0.6, -0.1] × 10-2 ppb yr-1). Zugspitze methane and ethane time series are significantly correlated for the period 2007-2014 and can be assigned to thermogenic methane emissions with an ethane-to-methane ratio (EMR) of 12-19 %. We present optimized emission scenarios for 2007-2014 derived from an atmospheric two-box model. From our trend observations we infer a total ethane emission increase over the period 2007-2014 from oil and natural gas sources of 1-11 Tg yr-1 along with an overall methane emission increase of 24-45 Tg yr-1. Based on these results, the oil and natural gas emission contribution (C) to the renewed methane increase is deduced using three different emission scenarios with dedicated EMR ranges. Reference scenario 1 assumes an oil and gas emission combination with EMR = 7

  4. Natural abundances of 15N and 13C in leaves of some N2-fixing and non-N2-fixing trees and shrubs in Syria.

    PubMed

    Kurdali, F; Al-Shamma'a, M

    2009-09-01

    A survey study was conducted on man-made plantations located at two different areas in the arid region of Syria to determine the variations in natural abundances of the (15)N and (13)C isotopes in leaves of several woody legume and non-legume species, and to better understand the consequence of such variations on nitrogen fixation and carbon assimilation. In the first study area (non-saline soil), the delta(15)N values in four legume species (Acacia cyanophylla,-1.73 per thousand Acacia farnesiana,-0.55 per thousand Prosopis juliflora,-1.64 per thousand; and Medicago arborea,+1.6 \\textperthousand) and one actinorhizal plant (Elaeagnus angustifolia,-0.46 to-2.1 per thousand) were found to be close to that of the atmospheric value pointing to a major contribution of N(2) fixing in these species; whereas, delta(15)N values of the non-fixing plant species were highly positive. delta(13)C per thousand; in leaves of the C3 plants were found to be affected by plant species, ranging from a minimum of-28.67 per thousand; to a maximum of-23 per thousand. However, they were relatively similar within each plant species although they were grown at different sites. In the second study area (salt affected soil), a higher carbon discrimination value (Delta(13)C per thousand) was exhibited by P. juliflora, indicating that the latter is a salt tolerant species; however, its delta(15)N was highly positive (+7.03 per thousand) suggesting a negligible contribution of the fixed N(2). Hence, it was concluded that the enhancement of N(2) fixation might be achieved by selection of salt-tolerant Rhizobium strains. PMID:20183233

  5. Core-shell molecularly imprinted polymer nanoparticles with assistant recognition polymer chains for effective recognition and enrichment of natural low-abundance protein.

    PubMed

    Liu, Dejing; Yang, Qian; Jin, Susu; Song, Yingying; Gao, Junfei; Wang, Ying; Mi, Huaifeng

    2014-02-01

    Core-shell molecular imprinting of nanomaterials overcomes difficulties with template transfer and achieves higher binding capacities for macromolecular imprinting, which are more important to the imprinting of natural low-abundance proteins from cell extracts. In the present study, a novel strategy of preparing core-shell nanostructured molecularly imprinted polymers (MIPs) was developed that combined the core-shell approach with assistant recognition polymer chains (ARPCs). Vinyl-modified silica nanoparticles were used as support and ARPCs were used as additional functional monomers. Immunoglobulin heavy chain binding protein (BiP) from the endoplasmic reticulum (ER) was chosen as the model protein. The cloned template protein BiP was selectively assembled with ARPCs from their library, which contained numerous limited-length polymer chains with randomly distributed recognition and immobilization sites. The resulting complex was copolymerized onto the surface of vinyl-modified silica nanoparticles under low concentrations of the monomers. After template removal, core-shell-structured nanoparticles with a thin imprinted polymer layer were produced. The particles demonstrated considerably high adsorption capacity, fast adsorption kinetics and selective binding affinities toward the template BiP. Furthermore, the synthesized MIP nanoparticles successfully isolated cloned protein BiP from protein mixtures and highly enriched BiP from an ER extract containing thousands of kinds of proteins. The enrichment reached 115-fold and the binding capacity was 5.4 μg g(-1), which were higher than those achieved by using traditional MIP microspheres. The advantageous properties of MIP nanoparticles hold promise for further practical applications in biology, such as protein analysis and purification. PMID:24140608

  6. A critical size and period hypothesis to explain natural regulation of salmon abundance and the linkage to climate and climate change

    NASA Astrophysics Data System (ADS)

    Beamish, R. J.; Mahnken, Conrad

    We hypothesise that salmon year class strength is determined in two stages during the first year in the ocean. There is an early natural mortality that is mostly related to predation, which is followed by a physiologically-based mortality. Juvenile salmon that fail to reach a critical size by the end of their first marine summer do not survive the following winter. In this study we describe our initial tests of this critical size and critical period hypothesis using data from ocean surveys of juvenile salmon and from experimental feeding studies on coho. Conservative swept volume abundance estimates for juvenile coho, and possibly chinook, indicate that there is high mortality in fall and winter during their first year in the sea. Studies of otolith weight show that the length and otolith-weight relationship for young coho changes in the early fall of their first ocean year. Studies of growth and associated hormone levels in feeding studies show that slow growing juvenile coho are stunted and deficient in an insulin-like growth factor-I (IGF-I). Juvenile coho sampled in September had low IGF-I values, indicative of poor growth. The results of these studies provide evidence for the general hypothesis that growth-related mortality occurs late in the first marine year and may be important in determining the strength of the year class (brood year). The link between total mortality and climate could be operating via the availability of nutrients regulating the food supply and hence competition for food (i.e. bottom-up regulation).

  7. [Responses of Soil and Plant 15N Natural Abundance to Long-term N Addition in an N-Saturated Pinus massoniana Forest in Southwest China].

    PubMed

    Liu, Wen-jing; Kang, Rong-hua; Zhang, Ting; Zhu, Jing; Duan, Lei

    2015-08-01

    Increasing N deposition in China will possibly cause N saturation of forest ecosystem, further resulting in a series of serious environmental problems. In order to explore the response of forest ecosystem to N deposition in China, and further evaluate and predict the N status of ecosystem, the 15N natural abundance (delta 15N) of soil and plants was measured in a typical Masson pine (Pinus massoniana) forest in southwest China to examine the potential use of delta 15N enrichment factor (epsilon(p/s)) as an effective indicator of N status. Long-term high N addition could significantly increase delta 15N of soil and plants, which was suggested by an on-going N fertilizing experiment with NH4NO3 or NaNO3 for 7 years. Meanwhile, delta 15N of soil and plants under NH, deposition was significantly higher than that under NO- deposition, suggesting different responses of ecosystem to different N-forms of deposition. The "N enrichment factor (epsilon(p/s)) had positive correlations with N deposition, N nitrification, and N leaching in the soil water. Linear correlation between "N enrichment factor and N deposition was found for all Masson pine forests investigated in this and previous studies in China, demonstrating that 15N enrichment factor could be used as an indicator of N status. The NH3 emission control should also be carried out accompanying with NOx emission control in the future, because NH4- deposition had significantly greater impact on the forest ecosystem than NO3- deposition with the same equivalence. PMID:26592030

  8. Carbon-13 natural abundance signatures of long-chain fatty acids to determinate sediment origin: A case study in northeast Austria

    NASA Astrophysics Data System (ADS)

    Mabit, Lionel; Gibbs, Max; Meusburger, Katrin; Toloza, Arsenio; Resch, Christian; Klik, Andreas; Swales, Andrew; Alewell, Christine

    2016-04-01

    - Several recently published information from scientific research have highlighted that compound-specific stable isotope (CSSI) signatures of fatty acids (FAs) based on the measurement of carbon-13 natural abundance signatures showed great promises to identify sediment origin. The authors have used this innovative isotopic approach to investigate the sources of sediment in a three hectares Austrian sub-watershed (i.e. Mistelbach). Through a previous study using the Cs-137 technique, Mabit et al. (Geoderma, 2009) reported a local maximum sedimentation rate reaching 20 to 50 t/ha/yr in the lowest part of this watershed. However, this study did not identify the sources. Subsequently, the deposited sediment at its outlet (i.e. the sediment mixture) and representative soil samples from the four main agricultural fields - expected to be the source soils - of the site were investigated. The bulk delta carbon-13 of the samples and two long-chain FAs (i.e. C22:0 and C24:0) allowed the best statistical discrimination. Using two different mixing models (i.e. IsoSource and CSSIAR v1.00) and the organic carbon content of the soil sources and sediment mixture, the contribution of each source has been established. Results suggested that the grassed waterway contributed to at least 50% of the sediment deposited at the watershed outlet. This study, that will require further validation, highlights that CSSI and Cs-137 techniques are complementary as fingerprints and tracers for establishing land sediment redistribution and could provide meaningful information for optimized decision-making by land managers.

  9. Cellulose nanocrystals, nanofibers, and their composites as renewable smart materials

    NASA Astrophysics Data System (ADS)

    Kim, Jaehwan; Zhai, Lindong; Mun, Seongcheol; Ko, Hyun-U.; Yun, Young-Min

    2015-04-01

    Cellulose is one of abundant renewable biomaterials in the world. Over 1.5 trillion tons of cellulose is produced per year in nature by biosynthesis, forming microfibrils which in turn aggregate to form cellulose fibers. Using new effective methods these microfibrils can be disintegrated from the fibers to nanosized materials, so called cellulose nanocrystal (CNC) and cellulose nanofiber (CNF). The CNC and CNF have extremely good strength properties, dimensional stability, thermal stability and good optical properties on top of their renewable behavior, which can be a building block of new materials. This paper represents recent advancement of cellulose nanocrystals and cellulose nanofibers, followed by their possibility for smart materials. Natural behaviors, extraction, modification of cellulose nanocrystals and fibers are explained and their synthesis with nanomaterials is introduced, which is necessary to meet the technological requirements for smart materials. Also, its challenges are addressed.

  10. Conformational study of C8 diazocine turn mimics using {sup 3}J{sub CH} coupling constants with {sup 13}C in natural abundance

    SciTech Connect

    Bean, J.W.; Briand, J.; Burgess, J.L.; Callahan, J.F.

    1994-12-01

    The conformations of two diazocine turn mimics, which were later incorporated into GPIIb/IIIa peptide antagonists, were investigated using nuclear magnetic resonance techniques. The two compounds, methyl (2,5-dioxo-3-(S)-(3-{omega}-tosylguanidino-propyl)-4-methyl-octahydro-1,4-dazocin-1-yl)acetate (1) and methyl (2,5-dioxo-3-(S)-(3-{omega}-tosyl-guanidino-propyl)-octahydro-1,5-diazocin-1-yl)acetate (2), differ only in their substituent at the diazocine position 4 nitrogen, yet this substitution results in a marked difference in the affinity of the resulting analogs for the GPIIb/IIIa receptor. It was of interest to determine if the difference observed in the antagonistic potency between these analogs was related to constitutional or, perhaps, conformational differences. The backbone conformations of these two molecules can be determined by measuring vicinal coupling constants along the trimethylene portion of the C8 ring backbone and by measuring interproton NOE intensities between the diazocine methine proton and the protons of the trimethylene group. For compound 1, {sup 3}J{sub HH} values measured from a P.E.COSY spectrum and interproton distances calculated from ROESY buildup curves indicated the presence of a single C8 ring backbone conformation where the trimethylene bridge adopted a staggered conformation and the H{alpha}1 and H{gamma}1 protons of the trimethylene group were 2.2 A from the methine proton. For compound 2, however, partial overlap of the central H{beta}1 and H{beta}2 protons made it impossible to measure {sup 3}J{sub HH} values from the P.E.COSY spectrum. We therefore used a {sup 13}C-filtered TOCSY experiment to measure the {sup 3}J{sub CH} values in both compounds 1 and 2. These heteronuclear vicinal coupling constants measured with {sup 13}C in natural abundance in conjunction with measured interproton NOE intensities indicate that these compounds share a common C8 ring backbone conformation.

  11. Reevaluation of siderophile element abundances and ratios across the Cretaceous-Paleogene (K-Pg) boundary: Implications for the nature of the projectile

    NASA Astrophysics Data System (ADS)

    Goderis, S.; Tagle, R.; Belza, J.; Smit, J.; Montanari, A.; Vanhaecke, F.; Erzinger, J.; Claeys, Ph.

    2013-11-01

    The discovery over 30 years ago at Gubbio (Italy) and Caravaca (Spain) of an enrichment in the concentrations of iridium (Ir) and the other platinum group elements (PGE) by up to four orders of magnitude (Irmax = 0.10-87 ng/g) compared to average continental crustal background levels remains one of the most important discoveries in the Earth sciences. Since then, similar anomalies have been detected in more than 120 Cretaceous-Paleogene (K-Pg) boundary sites worldwide. Highly elevated Ir and other siderophile element abundances in roughly chondritic ratios are considered strong indicators for the presence of a meteoritic contribution in impact-related lithologies (melt rocks, impact ejecta material, etc.), delivered when an extraterrestrial object strikes Earth. The presented work adds 113 unpublished PGE analyses of 38 K-Pg sections worldwide to the existing literature. The analytical protocol relied on for this purpose consisted of a combination of a nickel-sulfide fire assay pre-concentration technique and subsequent trace metal determination via inductively coupled plasma-mass spectrometry (ICP-MS). Through repeated determination of key siderophile elements (i.e., Cr, Co, Ni, and PGE), the importance of sampling, nugget effects, and analytical methodologies applied becomes more apparent. Even more critically, these analytical effects are superimposed by the local syn- and post-depositional conditions that have affected the pristine meteoritic signature of the K-Pg impactor, including potential fractionation during vaporization and condensation, dissimilar PGE carrier phases, terrestrial PGE input, sedimentation rate, reworking, diagenesis, bioturbation, and chemical diffusion. While chondrite-normalized PGE patterns of individual sites appear relatively flat (i.e., chondritic), strong variations in siderophile element content and inter-element ratios exist between K-Pg locations, inter-laboratory measurements, and replicate analyses, hampering a precise

  12. Quantifying remobilization of pre-existing nitrogen from cuttings to new growth of woody plants using 15N at natural abundance

    PubMed Central

    2013-01-01

    Background For measurements of nitrogen isotope composition at natural abundance, carry-over of pre-existing nitrogen remobilized to new plant growth can cause deviation of measured isotope composition (δ15N) from the δ15Nof newly acquired nitrogen. To account for this problem, a two-step approach was proposed to quantify and correct for remobilized nitrogen from vegetative cuttings of Populus balsamifera L. grown with either nitrate (δ15N = 58.5‰) or ammonium (δ15N = −0.96‰). First, the fraction of carry-over nitrogen remaining in the cutting was estimated by isotope mass balance. Then measured δ15N values were adjusted for the fraction of pre-existing nitrogen remobilized to the plant. Results Mean plant δ15N prior to correction was 49‰ and −5.8‰ under nitrate and ammonium, respectively. Plant δ15N was non-linearly correlated to biomass (r2 = 0.331 and 0.249 for nitrate and ammonium, respectively; P < 0.05) where the δ15N of plants with low biomass approached the δ15N of the pre-existing nitrogen. Approximately 50% of cutting nitrogen was not remobilized, irrespective of size. The proportion of carry-over nitrogen in new growth was not different between sources but ranged from less than 1% to 21% and was dependent on plant biomass and, to a lesser degree, the size of the cutting. The δ15N of newly acquired nitrogen averaged 52.7‰ and −6.4‰ for nitrate and ammonium-grown plants, respectively; both lower than their source values, as expected. Since there was a greater difference in δ15N between the carried-over pre-existing and newly assimilated nitrogen where nitrate was the source, the difference between measured δ15N and adjusted δ15N was also greater. There was no significant relationship between biomass and plant δ15N with either ammonium or nitrate after adjusting for carry-over nitrogen. Conclusion Here, we provide evidence of remobilized pre-existing nitrogen influencing δ15N of new growth of P. balsamifera L

  13. Quantitation of metabolic compartmentation in hyperammonemic brain by natural abundance 13C-NMR detection of 13C-15N coupling patterns and isotopic shifts.

    PubMed

    Lapidot, A; Gopher, A

    1997-02-01

    In the present study, the removal of cerebral ammonia by glutamine synthetase (GS) and by reductive amination of 2-oxoglutarate by glutamate dehydrogenase in the presence of an amino donor group, was determined in hyperammonemic rabbit brains. The 15N enrichments of brain metabolite alpha-amino and amide positions of glutamine, glutamate, and alanine were determined by the indirect detection of 15N-labeled compounds of the 13C-15N spin coupling patterns of natural abundance 13C-NMR spectra. The 13C-NMR spectra of brain extracts were obtained from rabbits infused with 15NH4Cl with or without intraperitoneal infusion of the GS inhibitor, L-methionine DL-sulfoximine, in a reasonable acquisition time period. When 15NH4Cl was infused, [5-15N]glutamine and [2-15N]glutamine concentrations reached 5.2 mumol/100 mg protein and 3.6 mumol/100 mg protein, respectively, which indicates the relatively high activity of reductive amination of 2-oxoglutarate in the glutamate dehydrogenase reaction. The low concentration of [2-15N]glutamate, which is about 30% of that of [2-15N]glutamine obtained in this study, suggests that very little glutamine serves as a precursor of neuronal glutamate. When GS was inhibited by L-methionine DL-sulfoximine, a flux of 15NH4+ via the residual activity of GS was accompanied by an apparent increase of [2-15N]glutamate and [15N]alanine concentrations (2.9 mumol/100 mg protein and 1.8 mumol/100 mg protein, respectively). These findings and those obtained from 13C-13C isotopomer analysis (Lapidot and Gopher, 1994b) suggest that astrocytic 2-oxoglutarate is partially utilized (together with an amino group donor) as a precursor for neuronal glutamate in the hyperammonemic brain when GS is inhibited. This process can partly replace GS activity in metabolizing ammonia in the hyperammonemic rabbit brain. PMID:9057821

  14. NMR profiling of biomolecules at natural abundance using 2D 1H-15N and 1H-13C multiplicity-separated (MS) HSQC spectra

    NASA Astrophysics Data System (ADS)

    Chen, Kang; Freedberg, Darón I.; Keire, David A.

    2015-02-01

    2D NMR 1H-X (X = 15N or 13C) HSQC spectra contain cross-peaks for all XHn moieties. Multiplicity-edited1H-13C HSQC pulse sequences generate opposite signs between peaks of CH2 and CH/CH3 at a cost of lower signal-to-noise due to the 13C T2 relaxation during an additional 1/1JCH period. Such CHn-editing experiments are useful in assignment of chemical shifts and have been successfully applied to small molecules and small proteins (e.g. ubiquitin) dissolved in deuterated solvents where, generally, peak overlap is minimal. By contrast, for larger biomolecules, peak overlap in 2D HSQC spectra is unavoidable and peaks with opposite phases cancel each other out in the edited spectra. However, there is an increasing need for using NMR to profile biomolecules at natural abundance dissolved in water (e.g., protein therapeutics) where NMR experiments beyond 2D are impractical. Therefore, the existing 2D multiplicity-edited HSQC methods must be improved to acquire data on nuclei other than 13C (i.e.15N), to resolve more peaks, to reduce T2 losses and to accommodate water suppression approaches. To meet these needs, a multiplicity-separated1H-X HSQC (MS-HSQC) experiment was developed and tested on 500 and 700 MHz NMR spectrometers equipped with room temperature probes using RNase A (14 kDa) and retroviral capsid (26 kDa) proteins dissolved in 95% H2O/5% D2O. In this pulse sequence, the 1/1JXH editing-period is incorporated into the semi-constant time (semi-CT) X resonance chemical shift evolution period, which increases sensitivity, and importantly, the sum and the difference of the interleaved 1JXH-active and the 1JXH-inactive HSQC experiments yield two separate spectra for XH2 and XH/XH3. Furthermore we demonstrate improved water suppression using triple xyz-gradients instead of the more widely used z-gradient only water-suppression approach.

  15. Flow properties of natural rubber composites filled with defatted soy flour

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The linear and nonlinear viscoelastic properties of natural rubber composites reinforced with defatted soy flour were studied. Defatted soy flour is an abundant, renewable commodity, and its rigid nature makes it suitable as a reinforcement phase in rubber composites. At small strain, the elastic ...

  16. Naturally occurring fatty acids: source, chemistry and uses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural occurring fatty acids are a large and complex class of compounds found in plants and animals. Fatty acids are abundant and of interest because of their renewability, biodegradability, biocompatibility, low cost, and fascinating chemistry. Of the many fatty acids, only 20-25 of them are widel...

  17. GREEN COMPOSITES OF NATURAL RUBBER AND DEFATTED SOY FLOUR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Viscoelastic properties of natural rubber (NR) composites reinforced by defatted soy flour (DSF) are investigated. DSF is an abundant renewable commodity and has a lower material cost than carbon black (CB). DSF contains soy protein, soy carbohydrate, and soy whey. Aqueous dispersion of DSF was b...

  18. Abundance coefficients, a new method for measuring microorganism relative abundance

    USGS Publications Warehouse

    Forester, R.M.

    1977-01-01

    A new method of measuring the relative abundance of microorganisms by using a set of interrelated coefficients, termed 'abundance coefficients' or 'AC', is proposed. These coefficients provide a means of recording abundance for geometric density categories, and each density measurement represents an approximation of the Poisson parameter ??t. The AC is the natural logarithm of a 'characteristic value,' which is a particular number for each geometric density category. The 'characteristic values' are based upon a probabilistic error statement derived from the Poisson formula, and they present evidence for separation of the geometric category boundaries by e = 2.71828. The proposed AC provide a means for recording species abundance in a manner suitable for arithmetic manipulation, for population structure studies, and for the determination of practical limits for defining the presence or absence of a species. Further, these coefficients provide for both intrasample and intersample abundance comparisons. ?? 1977 Plenum Publishing Corporation.

  19. Opportunities for renewable energy sources in Central Asia countries

    SciTech Connect

    Obozov, A.J.; Loscutoff, W.V.

    1998-07-01

    This report presents an overview of the state of conventional energy sources and the potential for development of renewable energy sources in the Central Asia countries of Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan, and Tajikistan. The region has a population of about 50 million in an area of more than four million square kilometers. The per capita gross internal product is more than $2,500, although the economy has been declining the past five years. The area has substantial coal, oil, uranium, and natural gas reserves, although they are not distributed equally among the five countries. Energy production is such that the countries do not have to rely heavily on imports. One of the problems in Central Asia is that the energy prices are substantially below the world prices. This is a factor in development of renewable energy sources. The primary renewable energy resources available are wind in Kazakhstan, solar in the entire region, biomass in Kyrgyzstan, and micro-hydropower stations in Kazakhstan and Kyrgyzstan. All of these have the potential to provide a significant amount of the required energy for the region. However, all of the countries have an abundance of various renewable energy resources. To effectively use these resources, however, a number of barriers to their development and commercialization must be overcome. These include low prices of conventional energy sources, absence of legislative support, lack of financing for new technologies, and lack of awareness of renewable energy sources by the population. A number of specific actions are proposed to overcome these barriers. These include establishment of a Central Asia coordinating council for renewable energy, development of a regional renewable energy program, and setting up a number of large demonstration projects. 16 figs.

  20. Renewing Schools.

    ERIC Educational Resources Information Center

    McChesney, Jim

    1997-01-01

    This publication reviews works on educational reform that represent attempts to do more than merely respond in knee-jerk fashion to political pressure for reform. Bruce Joyce and Emily Calhoun, in "Learning Experiences in School Renewal: An Exploration of Five Successful Programs" (Eugene, Oregon: ERIC Clearinghouse on Educational Management,…

  1. Renewable Energy

    NASA Astrophysics Data System (ADS)

    Boyle, Godfrey

    2004-05-01

    Stimulated by recent technological developments and increasing concern over the sustainability and environmental impact of conventional fuel usage, the prospect of producing clean, sustainable power in substantial quantities from renewable energy sources arouses interest around the world. This book provides a comprehensive overview of the principal types of renewable energy--including solar, thermal, photovoltaics, bioenergy, hydro, tidal, wind, wave, and geothermal. In addition, it explains the underlying physical and technological principles of renewable energy and examines the environmental impact and prospects of different energy sources. With more than 350 detailed illustrations, more than 50 tables of data, and a wide range of case studies, Renewable Energy, 2/e is an ideal choice for undergraduate courses in energy, sustainable development, and environmental science. New to the Second Edition ·Full-color design ·Updated to reflect developments in technology, policy, attitides ·Complemented by Energy Systems and Sustainability edited by Godfrey Boyle, Bob Everett and Janet Ramage, all of the Open University, U.K.

  2. Coronal abundances and their variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1994-01-01

    This contract supports the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution software X-ray spectra from the Flat Crystal Spectrometer on NASA's Solar Maximum Mission. The goals of the study are a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This report is a summation of the data analysis and reporting activities which occurred since the last report, submitted two months early, in April 1994, to facilitate evaluation of the first year's progress for contract renewal. Hence this report covers the period 15 April 1994 - 15 December 1994. A list of publications resulting from this research is included.

  3. Abundance, Natural Infection with Trypanosomes, and Food Source of an Endemic Species of Triatomine, Panstrongylus howardi (Neiva 1911), on the Ecuadorian Central Coast

    PubMed Central

    Villacís, Anita G.; Ocaña-Mayorga, Sofía; Lascano, Mauricio S.; Yumiseva, César A.; Baus, Esteban G.; Grijalva, Mario J.

    2015-01-01

    The elimination of domestic triatomines is the foundation of Chagas disease control. Regional initiatives are eliminating introduced triatomine species. In this scenario, endemic triatomines can occupy the ecological niches left open and become a threat to long-term Chagas disease control efforts. This study determined the abundance, colonization, and Trypanosoma cruzi infection rate of the endemic Panstrongylus howardi in 10 rural communities located in Ecuador's Manabí Province. In total, 518 individuals of P. howardi were collected. Infestation indices of 1.4% and 6.6% were found in the domestic and peridomestic environments, respectively. We determined a T. cruzi infection rate of 53.2% (N = 47) in this species. P. howardi has a high capacity to adapt to different habitats, especially in the peridomicile. This implies a considerable risk of transmission because of the frequency of intradomicile invasion. Therefore, this species needs to be taken into account in Chagas control and surveillance efforts in the region. PMID:25385867

  4. Abundance, natural infection with trypanosomes, and food source of an endemic species of triatomine, Panstrongylus howardi (Neiva 1911), on the Ecuadorian Central Coast.

    PubMed

    Villacís, Anita G; Ocaña-Mayorga, Sofía; Lascano, Mauricio S; Yumiseva, César A; Baus, Esteban G; Grijalva, Mario J

    2015-01-01

    The elimination of domestic triatomines is the foundation of Chagas disease control. Regional initiatives are eliminating introduced triatomine species. In this scenario, endemic triatomines can occupy the ecological niches left open and become a threat to long-term Chagas disease control efforts. This study determined the abundance, colonization, and Trypanosoma cruzi infection rate of the endemic Panstrongylus howardi in 10 rural communities located in Ecuador's Manabí Province. In total, 518 individuals of P. howardi were collected. Infestation indices of 1.4% and 6.6% were found in the domestic and peridomestic environments, respectively. We determined a T. cruzi infection rate of 53.2% (N = 47) in this species. P. howardi has a high capacity to adapt to different habitats, especially in the peridomicile. This implies a considerable risk of transmission because of the frequency of intradomicile invasion. Therefore, this species needs to be taken into account in Chagas control and surveillance efforts in the region. PMID:25385867

  5. Robust Abundance Estimation in Animal Abundance Surveys with Imperfect Detection

    EPA Science Inventory

    Surveys of animal abundance are central to the conservation and management of living natural resources. However, detection uncertainty complicates the sampling process of many species. One sampling method employed to deal with this problem is depletion (or removal) surveys in whi...

  6. Evaluation of relative isotopic abundance measurements in a quadrupole time-of-flight mass spectrometer for elemental composition determination of natural products in traditional Chinese medicine.

    PubMed

    Wu, Zhi-Jun; Huo, Jia-Li; Chen, Jian-Zhong; Li, Na; Fang, Dong-Mei; Chen, Xiao-Zhen; Zhang, Guo-Lin; Wang, Jian-Hua; Xu, Xiao-Ying

    2013-01-01

    The relative isotopic abundance (RIA) measurement errors of a quadrupole time-of-flight (Q-ToF) instrument incorporating analog-to-digital converter detectors were systemically evaluated by stochastically collecting about 200 data in positive ion mass spectrometry (MS) mode. Errors varied with peak intensities at definite spectral acquisition rates but were very close, even if peak intensities changed sharply at different spectral acquisition rates with the same concentration. Intensity thresholds were systematically defined at 1 Hz of spectral acquisition rates. RIA measurement errors were also evaluated using peak area. It seemed that peak area was better adapted for the high-intensity ions while peak intensity was suited for very low-intensity ions. Several known compounds were selected for RIA measurements for product ions in tandem mass spectropmetry (MS/MS) mode. An extract of a representative traditional Chinese medicinal, Paederia scandens was analyzed with high-performance liquid chromatography-electrospray ionization-QToF-MS/MS. The unique elemental compositions of some compounds could not be identified even with exact masses and MS/MS spectra of measured and reference compounds. RIA errors, especially of (M+2)M(-1), provided vital information for determining the elemental composition. PMID:24261081

  7. Distributions and Transformations of Natural Abundance 14C and 13C in Dissolved and Particulate Lipids in a Major Temperate Estuary

    NASA Astrophysics Data System (ADS)

    Bauer, J. E.; Canuel, E. A.; McIntosh, H.; Barrett, A.; Ferer, E.; Hossler, K.

    2013-12-01

    Limited previous studies have shown major differences in the natural 14C and 13C isotopic signatures and radiocarbon ages of different biochemical classes (e.g., proteins, carbohydrates, lipid, etc.) in river, estuarine and marine dissolved and particulate organic matter (DOM and POM, respectively). Of particular note are the much greater radiocarbon ages of lipophilic materials than other compound classes. Possible explanations for these findings include greater-than-expected inputs of fossil and highly aged lipid-containing organic matter to rivers and estuaries, extended sorptive-protection of lipophilic materials from degradation and/or lower overall reactivities of lipids vs. other major biochemical classes. We measured the Delta 14C and del 13C signatures and 14C ages of lipid classes in DOM and POM in a major temperate estuary, Delaware Bay (USA) over two years. Changes in DOM were also followed during large volume dark and light incubations to assess the microbial and photochemical reactivity and processing of DOM and lipids. Neutral lipids in DOM were among the most highly aged (> 30,000 yrs BP) of any materials measured in natural waters to date, and were significantly older than co-occurring polar lipids (~4,000-5,000 yrs BP). In general, DOM lipid ages were significantly greater than POM lipid ages across the river-estuary transect, arguing against sorptive protection as the major factor explaining greater ages of lipid than those of other compound classes. Both dark and light incubations of DOM resulted in losses of very highly aged material (30-50,000 y BP), with the remnant exported lipids being correspondingly younger. The microbial and photochemical alterations were most pronounced for lipids from freshwater reaches of the system (i.e., the Delaware River). These findings suggest that a) dissolved vs. particulate lipids have fundamentally different sources and/or physico-chemical partitioning, b) different lipid classes (e.g., neutral vs. polar

  8. Assessment of marine-derived nutrients in the Copper River Delta, Alaska, using natural abundance of the stable isotopes of nitrogen, sulfur, and carbon

    USGS Publications Warehouse

    Kline, Thomas C.; Woody, Carol Ann; Bishop, Mary Anne; Powers, Sean P.; Knudsen, E. Eric

    2007-01-01

    We performed nitrogen, sulfur, and carbon stable isotope analysis (SIA) on maturing and juvenile anadromous sockeye and coho salmon, and periphyton in two Copper River delta watersheds of Alaska to trace salmonderived nutrients during 2003–2004. Maturing salmon were isotopically enriched relative to alternate freshwater N, S, and C sources as expected, with differences consistent with species trophic level differences, and minor system, sex, and year-to-year differences, enabling use of SIA to trace these salmon-derived nutrients. Periphyton naturally colonized, incubated, and collected using Wildco Periphtyon Samplers in and near spawning sites was 34S- and 15N-enriched, as expected, and at all freshwater sites was 13C-depleted. At nonspawning and coho-only sites, periphyton 34S and 15N was generally low. However, 34S was low enough at some sites to be suggestive of sulfate reduction, complicating the use of S isotopes. Juvenile salmon SIA ranged in values consistent with using production derived from re-mineralization as well as direct utilization, but only by a minority fraction of coho salmon. Dependency on salmon-derived nutrients ranged from relatively high to relatively low, suggesting a space-limited system. No one particular isotope was found to be superior for determining the relative importance of salmon-derived nutrients.

  9. Natural 13C abundance reveals trophic status of fungi and host-origin of carbon in mycorrhizal fungi in mixed forests

    PubMed Central

    Högberg, Peter; Plamboeck, Agneta H.; Taylor, Andrew F. S.; Fransson, Petra M. A.

    1999-01-01

    Fungi play crucial roles in the biogeochemistry of terrestrial ecosystems, most notably as saprophytes decomposing organic matter and as mycorrhizal fungi enhancing plant nutrient uptake. However, a recurrent problem in fungal ecology is to establish the trophic status of species in the field. Our interpretations and conclusions are too often based on extrapolations from laboratory microcosm experiments or on anecdotal field evidence. Here, we used natural variations in stable carbon isotope ratios (δ13C) as an approach to distinguish between fungal decomposers and symbiotic mycorrhizal fungal species in the rich sporocarp flora (our sample contains 135 species) of temperate forests. We also demonstrated that host-specific mycorrhizal fungi that receive C from overstorey or understorey tree species differ in their δ13C. The many promiscuous mycorrhizal fungi, associated with and connecting several tree hosts, were calculated to receive 57–100% of their C from overstorey trees. Thus, overstorey trees also support, partly or wholly, the nutrient-absorbing mycelia of their alleged competitors, the understorey trees. PMID:10411910

  10. Renewing governance.

    PubMed

    Loos, Gregory P

    2003-01-01

    Globalization's profound influence on social and political institutions need not be negative. Critics of globalization have often referred to the "Impossible Trinity" because decision-making must 1. respect national sovereignty, 2. develop and implement firm regulation, and 3. allow capital markets to be as free as possible. To many, such goals are mutually exclusive because history conditions us to view policy-making and governance in traditional molds. Thus, transnational governance merely appears impossible because current forms of governance were not designed to provide it. The world needs new tools for governing, and its citizens must seize the opportunity to help develop them. The rise of a global society requires a greater level of generality and inclusion than is found in most policy bodies today. Politicians need to re-examine key assumptions about government. States must develop ways to discharge their regulatory responsibilities across borders and collaborate with neighboring jurisdictions, multilateral bodies, and business. Concepts such as multilateralism and tripartism show great promise. Governments must engage civil society in the spirit of shared responsibility and democratic decision-making. Such changes will result in a renewal of the state's purpose and better use of international resources and expertise in governance. PMID:17208717

  11. Proton-detected 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H-1H RFDR mixing on a natural abundant sample under ultrafast MAS

    NASA Astrophysics Data System (ADS)

    Pandey, Manoj Kumar; Nishiyama, Yusuke

    2015-09-01

    In this contribution, we have demonstrated a proton detection-based approach on a natural abundant powdered L-Histidine HCl-H2O sample at ultrafast magic angle spinning (MAS) to accomplish 14N/14N correlation from a 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H finite-pulse radio frequency-driven recoupling (fp-RFDR). Herein the heteronuclear magnetization transfer between 14N and 1H has been achieved by HMQC experiment, whereas 14N/14N correlation is attained through enhanced 1H-1H spin diffusion process due to 1H-1H dipolar recoupling during the RFDR mixing. While the use of ultrafast MAS (90 kHz) provides sensitivity enhancement through increased 1H transverse relaxation time (T2), the use of micro-coil probe which can withstand strong 14N radio frequency (RF) fields further improves the sensitivity per unit sample volume.

  12. 13C Natural Abundance of Serum Retinol Is a Novel Biomarker for Evaluating Provitamin A Carotenoid-Biofortified Maize Consumption in Male Mongolian Gerbils123

    PubMed Central

    Pungarcher, India; Mourao, Luciana; Davis, Christopher R; Simon, Philipp; Pixley, Kevin V; Tanumihardjo, Sherry A

    2016-01-01

    Background: Crops such as maize, sorghum, and millet are being biofortified with provitamin A carotenoids to ensure adequate vitamin A (VA) intakes. VA assessment can be challenging because serum retinol concentrations are homeostatically controlled and more sensitive techniques are resource-intensive. Objectives: We investigated changes in serum retinol relative differences of isotope amount ratios of 13C/12C (δ13C) caused by natural 13C fractionation in C3 compared with C4 plants as a biomarker to detect provitamin A efficacy from biofortified (orange) maize and high-carotene carrots. Methods: The design was a 2 × 2 × 2 maize (orange compared with white) by carrot (orange compared with white) by a VA fortificant (VA+ compared with VA−) in weanling male Mongolian gerbils (n = 55), which included a 14-d VA depletion period and a 62-d treatment period (1 baseline and 8 treatment groups; n = 5−7/group). Liver VA and serum retinol were quantified, purified by HPLC, and analyzed by GC combustion isotope ratio mass spectrometry for 13C. Results: Treatments affected liver VA concentrations (0.048 ± 0.039 to 0.79 ± 0.24 μmol/g; P < 0.0001) but not overall serum retinol concentrations (1.38 ± 0.22 μmol/L). Serum retinol and liver VA δ13C were significantly correlated (R2 = 0.92; P < 0.0001). Serum retinol δ13C differentiated control groups that consumed white maize and white carrots (−27.1 ± 1.2 δ13C‰) from treated groups that consumed orange maize and white carrots (−21.6 ± 1.4 δ13C‰ P < 0.0001) and white maize and orange carrots (−30.6 ± 0.7 δ13C‰ P < 0.0001). A prediction model demonstrated the relative contribution of orange maize to total dietary VA for groups that consumed VA from mixed sources. Conclusions: Provitamin A efficacy and quantitative estimation of the relative contribution to dietary VA were demonstrated with the use of serum retinol δ13C. This method could be used for maize efficacy or effectiveness studies and with

  13. Human and climate impact on ¹⁵N natural abundance of plants and soils in high-mountain ecosystems: a short review and two examples from the Eastern Pamirs and Mt. Kilimanjaro.

    PubMed

    Zech, Michael; Bimüller, Carolin; Hemp, Andreas; Samimi, Cyrus; Broesike, Christina; Hörold, Claudia; Zech, Wolfgang

    2011-09-01

    Population pressure increasingly endangers high-mountain ecosystems such as the pastures in the Eastern Pamirs and the mountain forests on Mt. Kilimanjaro. At the same time, these ecosystems constitute the economic basis for millions of people living there. In our study, we, therefore, aimed at characterising the land-use effects on soil degradation and N-cycling by determining the natural abundance of (15)N. A short review displays that δ(15)N of plant-soil systems may often serve as an integrated indicator of N-cycles with more positive δ(15)N values pointing towards N-losses. Results for the high-mountain pastures in the Eastern Pamirs show that intensively grazed pastures are significantly enriched in (15)N compared to the less-exploited pastures by 3.5 ‰, on average. This can be attributed to soil organic matter degradation, volatile nitrogen losses, nitrogen leaching and a general opening of the N-cycle. Similarly, the intensively degraded savanna soils, the cultivated soils and the soils under disturbed forests on the foothill of Mt. Kilimanjaro reveal very positive δ(15)N values around 6.5 ‰. In contrast, the undisturbed forest soils in the montane zone are more depleted in (15)N, indicating that here the N-cycle is relatively closed. However, significantly higher δ(15)N values characterise the upper montane forest zone at the transition to the subalpine zone. We suggest that this reflects N-losses by the recently monitored and climate change and antropogenically induced increasing fire frequency pushing the upper montane rainforest boundary rapidly downhill. Overall, we conclude that the analysis of the (15)N natural abundance in high-mountain ecosystems is a purposeful tool for detecting land-use- or climate change-induced soil degradation and N-cycle opening. PMID:21745030

  14. Curriculum Renewal.

    ERIC Educational Resources Information Center

    Glatthorn, Allan A.

    This book is a manual for educators to use in curriculum planning and development. Chapter 1 examines the nature of curriculum and its relationship to instruction by (1) defining curriculum and the four main levels of curriculum work (curriculum policy, field of study, program of studies, and course) and (2) distinguishing between six types of…

  15. Diterpenoid Biopolymers: New Directions for Renewable Materials Engineering

    PubMed Central

    Hillwig, Matthew L.; Mann, Francis M.; Peters, Reuben J.

    2010-01-01

    Most types of ambers are naturally occurring, relatively hard, durable resinite polymers derived from the exudates of trees. This resource has been coveted for thousands of years due to its numerous useful properties in industrial processes, beauty, and purported medicinal properties. Labdane diterpenoid based ambers represent the most abundant and important resinites on earth. These resinites are a dwindling, non-renewable natural resource, so a new source of such materials needs to be established. Recent advances in sequencing technologies and biochemical engineering are rapidly accelerating the rate of identifying and assigning function to genes involved in terpenoid biosynthesis, as well as producing industrial-scale quantities of desired small-molecules in bacteria and yeast. This has provided new tools for engineering metabolic pathways capable of producing diterpenoid monomers that will enable the production of custom-tailored resinite-like polymers. Furthermore, this biosynthetic toolbox is continuously expanding, providing new possibilities for renewing dwindling stocks of naturally occurring resinite materials and engineering new materials for future applications. PMID:20857504

  16. VISCOELASTIC PROPERTIES OF NATURAL RUBBER COMPOSITES REINFORCED BY DEFATTED SOY FLOUR AND CARBON BLACK CO-FILLER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Filler mixtures of defatted soy flour (DSF) and carbon black (CB) were used to reinforce natural rubber (NR) composites and their viscoelastic properties were investigated. DSF is an abundant and renewable commodity and has a lower material cost than CB. Aqueous dispersions of DSF and CB were firs...

  17. Solar abundance of osmium

    PubMed Central

    Jacoby, George; Aller, Lawrence H.

    1976-01-01

    The abundance parameter, log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance (by numbers of atoms with respect to hydrogen), has been derived for three lines of osmium by a method of spectrum synthesis. An apparent discordance of the derived abundance with that found from the carbonaceous chondrites is probably to be attributed primarily to errors in the f-values, and blending with unknown contributors. PMID:16592314

  18. Evaluating Investments in Natural Gas Vehicles and Infrastructure for Your Fleet: Vehicle Infrastructure Cash-Flow Estimation -- VICE 2.0; Clean Cities, Energy Efficiency & Renewable Energy (EERE)

    SciTech Connect

    Gonzales, John

    2015-04-02

    Presentation by Senior Engineer John Gonzales on Evaluating Investments in Natural Gas Vehicles and Infrastructure for Your Fleet using the Vehicle Infrastructure Cash-flow Estimation (VICE) 2.0 model.

  19. Building a Business Case for Compressed Natural Gas in Fleet Applications

    SciTech Connect

    Mitchell, G.

    2015-03-19

    Natural gas is a clean-burning, abundant, and domestically produced source of energy. Compressed natural gas (CNG) has recently garnered interest as a transportation fuel because of these attributes and because of its cost savings and price stability compared to conventional petroleum fuels. The National Renewable Energy Laboratory (NREL) developed the Vehicle Infrastructure and Cash-Flow Evaluation (VICE) model to help businesses and fleets evaluate the financial soundness of CNG vehicle and CNG fueling infrastructure projects.

  20. Butanol production from renewable biomass by clostridia.

    PubMed

    Jang, Yu-Sin; Malaviya, Alok; Cho, Changhee; Lee, Joungmin; Lee, Sang Yup

    2012-11-01

    Global energy crisis and limited supply of petroleum fuels have rekindled the worldwide focus towards development of a sustainable technology for alternative fuel production. Utilization of abundant renewable biomass offers an excellent opportunity for the development of an economical biofuel production process at a scale sufficiently large to have an impact on sustainability and security objectives. Additionally, several environmental benefits have also been linked with the utilization of renewable biomass. Butanol is considered to be superior to ethanol due to its higher energy content and less hygroscopy. This has led to an increased research interest in butanol production from renewable biomass in recent years. In this paper, we review the various aspects of utilizing renewable biomass for clostridial butanol production. Focus is given on various alternative substrates that have been used for butanol production and on fermentation strategies recently reported to improve butanol production. PMID:22939593

  1. Developing a Natural Gas-Powered Bus Rapid Transit Service: A Case Study on Leadership: Roaring Fork Transportation Authority (Presentation); NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Schroeder, A.

    2015-03-01

    The Roaring Fork Transportation Authority (RFTA) represents a series of unique successes in alternative fuel deployment by pushing the envelope with innovative solutions. In the last year, RFTA demonstrated the ability to utilize compressed natural gas buses at a range of altitudes, across long distances, in extreme weather conditions and in a modern indoor fueling and maintenance facility - allwhile saving money and providing high-quality customer service. This case study will highlight how the leadership of organizations and communities that are implementing advances in natural gas vehicle technology is paving the way for broader participation.

  2. Renewable energy annual 1996

    SciTech Connect

    1997-03-01

    This report presents summary data on renewable energy consumption, the status of each of the primary renewable technologies, a profile of each of the associated industries, an analysis of topical issues related to renewable energy, and information on renewable energy projects worldwide. It is the second in a series of annual reports on renewable energy. The renewable energy resources included in the report are biomass (wood and ethanol); municipal solid waste, including waste-to-energy and landfill gas; geothermal; wind; and solar energy, including solar thermal and photovoltaic. The report also includes various appendices and a glossary.

  3. Capella: Structure and Abundances

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy S.

    1999-01-01

    This grant covers the analysis of ASCA spectra of the cool star binary system Capella. This project has also required the analysis of simultaneous EUVE data. The ASCA spectrum of Capella could not be fit with standard models; by imposing models based on strong lines observed with EUVE, a problem wavelength region was identified. Correcting the problem required calculations of atomic collision strengths of higher principal quantum number than had ever been calculated, resulting in a paper in process by Liedahl and Brickhouse. With these new models applied to the ASCA spectrum, better fits were obtained. While solar abundance ratios are generally consistent with the ASCA data, the ratio of Ne/Fe is three to four times lower than solar photospheric values. Whether there is a general First Ionization Potential (FIP) effect or a specific neon anomaly cannot be determined from these data. Detailed discussion has been provided to NASA in the most recent annual report (1997). Two poster presentations have been made regarding modeling requirements. A substantial paper is in the final revision form, following review by six co-authors. The results of this work have wide implications, since the newly calculated emission lines almost certainly contribute to other problems in fitting not only other stellar spectra, but also composite supernova remnants, galaxies, and cooling flow clusters of galaxies. Furthermore, Liedahl and Brickhouse have identified other species for which lines of a similar nature (high principal quantum number) will contribute significant flux. For moderate resolution X-ray spectra, lines left out of the models in relatively isolated bands, will be attributed to continuum flux by spectral fitting engines, causing errors in line-to-continuum ratios. Thus addressing the general theoretical problem is of crucial importance.

  4. Abundances of Natural Radionuclides (40K, 238U, 232Th) in Hanford and Rifle Integrated Field Research Challenge Site Sediments and the Application to the Estimation of Grain Size Distributions

    NASA Astrophysics Data System (ADS)

    Draper, K.; Ward, A. L.; Yabusaki, S.; Murray, C. J.; Greenwood, J.

    2009-12-01

    The distribution and geometry of lithofacies impact groundwater flow and solute spreading but are difficult to characterize at the scale controlling transport. We hypothesize that differences in γ-ray activity resulting from the natural distribution of 40K, 238U, and 232Th (K, U, T) are due to hydraulic separation and sorting and can be used to infer grain-size distributions at the scale of borehole γ-ray logs. The objective of this study was to investigate the feasibility of using γ-ray spectra to detect differences in grain size distributions as a means of characterizing small-scale variations in flow and reactive transport properties. The γ-ray spectra of whole and fractionated sediments from the Hanford and Old Rifle IFRC sites were characterized along with their grain size distributions. In the Hanford sediments, the abundance of K, U, and T was strongly correlated with the extent of weathering and with mean grain size. Hanford clay showed concentrations of 4%, 5.5 ppm, and 6.5 ppm for K, U, and T respectively. An increase in geometric mean diameter from 0.02 mm (clay) to 45.25 mm (very coarse gravel) showed increases in concentrations of 70% for K, 76% for U, and 83% for T. Old Rifle sediments showed no correlation between grain size and K, but there was an 81% increase in U and a 73 % increase in T. Cross plots of Th/U and Th/K also show strong correlations with grain size. The enrichment of natural isotopes with decreasing grain size is likely due to the increase in specific surface area. Thus, borehole γ-ray spectra could have a much wider application in characterizing grain separation and sorting and ultimately flow and reactive transport properties.

  5. Recent advances in the analysis of the site-specific isotopic fractionation of metabolites such as fatty acids using anisotropic natural-abundance 2H NMR spectroscopy: application to conjugated linolenic methyl esters.

    PubMed

    Lesot, Philippe; Serhan, Zeinab; Billault, Isabelle

    2011-01-01

    The full elucidation of the enzymatic mechanisms leading to polyunsaturated ω-3 to ω-5 fatty acids (PUFAs) occurring in plants or microorganisms by analyzing their site-specific isotopic fractionation profiles is a challenging task. Isotropic SNIF-NMR® method is an historical, powerful tool for the determination of ((2)H/(1)H) ratios. However, the absence of accessible isotopic data on the enantiotopic hydrogen sites (CH(2) groups) prevents the study of the enzymatic reaction stereoselectivity. Natural-abundance deuterium (NAD) 2D NMR experiment using chiral liquid crystals (CLC) as solvent is a new tool in this field, overcoming this limitation. In this work, we have explored various possibilities for optimizing the enantio-discrimination properties of CLC by changing the nature of the polypeptide and/or increasing the polarity of the organic co-solvents. We report also the first applications of TMU as co-solvent for preparing enantio-discriminating, homogenous polypeptide mesophases. The various experimental NAD NMR results recorded at an optimal sample temperature are discussed and compared in terms of number of discriminated (2)H sites and magnitude of spectral separation for different PUFAs such as the linoleic and linolenic acids. The comparison of all NMR results shows that optimal results are obtained when CLC mixtures made of poly-γ-benzyl-L-glutamate (PBLG) and high polarity co-solvents are used. As new challenging examples of applications, we report the preliminary analytical results obtained from two ω-5 conjugated linolenic acids: the α-eleostearic acid (9Z, 11E, 13E) and the punicic acid (9Z, 11E, 13Z). NMR data are discussed in terms of molecular orientational ordering parameters and isotopic distribution. PMID:21107978

  6. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2012-10-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  7. Renewable energy technology characterizations

    SciTech Connect

    None, None

    1997-12-01

    The Renewable Energy Technology Characterizations front matter lists the chapters and tables that support this report on the technical and economic status of the major emerging renewable energy options for electricity supply.

  8. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2013-04-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  9. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Hand, M. M.

    2012-09-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  10. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2012-11-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050.

  11. Application of Natural Isotopic Abundance ¹H-¹³C- and ¹H-¹⁵N-Correlated Two-Dimensional NMR for Evaluation of the Structure of Protein Therapeutics.

    PubMed

    Arbogast, Luke W; Brinson, Robert G; Marino, John P

    2016-01-01

    Methods for characterizing the higher-order structure of protein therapeutics are in great demand for establishing consistency in drug manufacturing, for detecting drug product variations resulting from modifications in the manufacturing process, and for comparing a biosimilar to an innovator reference product. In principle, solution NMR can provide a robust approach for characterization of the conformation(s) of protein therapeutics in formulation at atomic resolution. However, molecular weight limitations and the perceived need for stable isotope labeling have to date limited its practical applications in the biopharmaceutical industry. Advances in NMR magnet and console technologies, cryogenically cooled probes, and new rapid acquisition methodologies, particularly selective optimized flip-angle short transient pulse schemes and nonuniform sampling, have greatly ameliorated these limitations. Here, we describe experimental methods for the collection and analysis of 2D (1)H(N)-(15)N-amide- and (1)H-(13)C-methyl-correlated spectra applied to protein drug products at natural isotopic abundance, including representatives from the rapidly growing class of monoclonal antibody (mAb) therapeutics. Practical aspects of experimental setup and data acquisition for both standard and rapid acquisition NMR techniques are described. Furthermore, strategies for the statistical comparison of 2D (1)H(N)-(15)N-amide- and (1)H-(13)C-methyl-correlated spectra are detailed. PMID:26791974

  12. Raman and Theoretical Study of M2(dmp)4 [M = Cr (natural abundance Cr, 50Cr, and 54Cr) and Mo; dmp = 2,6-dimethoxyphenyl]. The Nature of Bonding in Complexes Containing ‘Supershort’ Metal-Metal Bonds

    PubMed Central

    Da Re, Ryan E.; Eglin, Judith L.; Carlson, Christin N.; John, Kevin D.; Morris, David E.; Woodruff, William H.; Bailey, James A.; Batista, Enrique; Martin, Richard L.; Cotton, F. Albert; Hillard, Elizabeth A.; Murillo, Carlos A.; Sattelberger, Alfred P.; Donohoe, Robert J.

    2010-01-01

    We report an investigation of complexes of the type M2(dmp)4 (M = Mo, Cr; dmp = 2,6-dimethoxyphenyl) using resonance Raman (RR) spectroscopy, Cr isotopic substitution, and density functional theory (DFT) calculations. Assignment of the Mo-Mo stretching vibration in the Mo2 species is straightforward as evidenced by a single resonance-enhanced band at 424 cm-1, consistent with an essentially unmixed metal-metal stretch, and overtones of this vibration. On the other hand, the Cr2 congener has no obvious metal-metal stretching mode near 650 - 700 cm-1, where empirical predictions based on the Cr-Cr distance as well as DFT calculations suggest that this vibration should appear if unmixed. Instead, three bands are observed at 345, 363, and 387 cm-1 that (a) have relative RR intensities that are sensitive to the Raman excitation frequency (b) exhibit overtones and combinations in the RR spectra, and (c) shift in frequency upon isotopic substitution (50Cr and 54Cr). DFT calculations are used to model the vibrational data for the Mo2 and Cr2 systems. Both the DFT results and empirical predictions are in good agreement with experimental observations in the Mo2 complex but both, while mutually consistent, differ radically from experiment in the Cr2 complex. Our experimental and theoretical results, especially the Cr isotope shifts, clearly demonstrate that the potential energy of the Cr-Cr stretching coordinate is distributed among several normal modes having both Cr-Cr and Cr-ligand character. The general significance of these results in interpreting spectroscopic observations in terms of the nature of metal-metal multiple bonding is discussed. PMID:20092271

  13. Pharmacological modulation of oncogenic Ras by natural products and their derivatives: Renewed hope in the discovery of novel anti-Ras drugs.

    PubMed

    Quah, Shun Ying; Tan, Michelle Siying; Teh, Yuan Han; Stanslas, Johnson

    2016-06-01

    Oncogenic rat sarcoma (Ras) is linked to the most fatal cancers such as those of the pancreas, colon, and lung. Decades of research to discover an efficacious drug that can block oncogenic Ras signaling have yielded disappointing results; thus, Ras was considered "undruggable" until recently. Inhibitors that directly target Ras by binding to previously undiscovered pockets have been recently identified. Some of these molecules are either isolated from natural products or derived from natural compounds. In this review, we described the potential of these compounds and other inhibitors of Ras signaling in drugging Ras. We highlighted the modes of action of these compounds in suppressing signaling pathways activated by oncogenic Ras, such as mitogen-activated protein kinase (MAPK) signaling and the phosphoinositide-3-kinase (PI3K) pathways. The anti-Ras strategy of these compounds can be categorized into four main types: inhibition of Ras-effector interaction, interference of Ras membrane association, prevention of Ras-guanosine triphosphate (GTP) formation, and downregulation of Ras proteins. Another promising strategy that must be validated experimentally is enhancement of the intrinsic Ras-guanosine triphosphatase (GTPase) activity by small chemical entities. Among the inhibitors of Ras signaling that were reported thus far, salirasib and TLN-4601 have been tested for their clinical efficacy. Although both compounds passed phase I trials, they failed in their respective phase II trials. Therefore, new compounds of natural origin with relevant clinical activity against Ras-driven malignancies are urgently needed. Apart from salirasib and TLN-4601, some other compounds with a proven inhibitory effect on Ras signaling include derivatives of salirasib, sulindac, polyamine, andrographolide, lipstatin, levoglucosenone, rasfonin, and quercetin. PMID:27016467

  14. OXYGEN ABUNDANCES IN CEPHEIDS

    SciTech Connect

    Luck, R. E.; Andrievsky, S. M.; Korotin, S. N.; Kovtyukh, V. V. E-mail: serkor@skyline.od.ua E-mail: scan@deneb1.odessa.ua

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  15. Species Abundance Patterns in Complex Evolutionary Dynamics

    NASA Astrophysics Data System (ADS)

    Tokita, Kei

    2004-10-01

    An analytic theory of species abundance patterns (SAPs) in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka-Volterra equation, with diverse interspecies interactions. Various SAPs observed in nature are derived from a single parameter. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g., gene expression.

  16. Renewable energy annual 1995

    SciTech Connect

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic.

  17. The effect of drought and interspecific interactions on the depth of water uptake in deep- and shallow-rooting grassland species as determined by δ18O natural abundance

    NASA Astrophysics Data System (ADS)

    Hoekstra, N. J.; Finn, J. A.; Lüscher, A.

    2014-03-01

    Increased incidence of weather drought, as predicted under climate change, has the potential to negatively affect grassland production. Compared to monocultures, vertical belowground niche complementarity between shallow- and deep-rooting species may be an important mechanism resulting in higher yields and higher resistance to drought in grassland mixtures. However, very little is known about the belowground responses in grassland systems and increased insight into these processes may yield important information both to predict the effect of future climate change and better design agricultural systems to cope with this. This study assessed the effect of a 10-week experimental summer drought on the depth of water uptake of two shallow-rooting species (Lolium perenne L. and Trifolium repens L.) and two deep-rooting species (Chicorium intybus L. and Trifolium pratense L.) in grassland monocultures and four-species-mixtures by using the natural abundance δ18O isotope method. We tested the following hypotheses: (1) drought results in a shift of water uptake to deeper soil layers, (2) deep-rooting species take up a higher proportion of water from deeper soil layers relative to shallow-rooting species, (3) as a result of interspecific interactions in mixtures, the water uptake of shallow-rooting species become shallower when grown together with deep-rooting species and vice versa, resulting in reduced niche overlap. The natural abundance δ18O technique provided novel insights into the depth of water uptake of deep- and shallow- rooting grassland species and revealed large shifts in response to drought and interspecific interactions. Compared to control conditions, drought reduced the proportional water uptake from 0-10 cm soil depth (PCWU0-10) of L. perenne, T. repens and C. intybus in monocultures by on average 54%. In contrast, the PCWU0-10 of T. pratense in monoculture increased by 44%, and only when grown in mixture did the PCWU0-10 of T. pratense decrease under

  18. Solar abundance of platinum

    PubMed Central

    Burger, Harry; Aller, Lawrence H.

    1975-01-01

    Three lines of neutral platinum, located at λ 2997.98 Å, λ 3064.71 Å, and λ 3301.86 Å have been used to determine the solar platinum abundance by the method of spectral synthesis. On the scale, log A(H) = 12.00, the thus-derived solar platinum abundance is 1.75 ± 0.10, in fair accord with Cameron's value of log A(Pt) = 1.69 derived by Mason from carbonaceous chondrites and calculated on the assumption that log A(Si) = 7.55 in the sun. PMID:16592278

  19. Stellar Oxygen Abundances

    NASA Astrophysics Data System (ADS)

    King, Jeremy

    1994-04-01

    This dissertation addresses several issues concerning stellar oxygen abundances. The 7774 {\\AA} O I triplet equivalent widths of Abia & Rebolo [1989, AJ, 347, 186] for metal-poor dwarfs are found to be systematically too high. I also argue that current effective temperatures used in halo star abundance studies may be ~150 K too low. New color-Teff relations are derived for metal-poor stars. Using the revised Teff values and improved equivalent widths for the 7774A O I triplet, the mean [O/Fe] ratio for a handful of halo stars is found to be +0.52 with no dependence on Teff or [Fe/H]. Possible cosmological implications of the hotter Teff scale are discussed along with additional evidence supporting the need for a higher temperature scale for metal-poor stars. Our Teff scale leads to a Spite Li plateau value of N(Li)=2.28 +/- 0.09. A conservative minimal primordial value of N(Li)=2.35 is inferred. If errors in the observations and models are considered, consistency with standard models of Big Bang nucleosynthesis is still achieved with this larger Li abundance. The revised Teff scale raises the observed B/Be ratio of HD 140283 from 10 to 12, making its value more comfortably consistent with the production of the observed B and Be by ordinary spallation. Our Teff values are found to be in good agreement with values predicted from both the Victoria and Yale isochrone color-Teff relations. Thus, it appears likely that no changes in globular cluster ages would result. Next, we examine the location of the break in the [O/Fe] versus [Fe/H] plane in a quantitative fashion. Analysis of a relatively homogeneous data set does not favor any unique break point in the range -1.7 /= -3), in agreement with the new results for halo dwarfs. We find that the gap in the observed [O/H] distribution, noted by Wheeler et al

  20. Abundances of light elements.

    PubMed Central

    Pagel, B E

    1993-01-01

    Recent developments in the study of abundances of light elements and their relevance to cosmological nucleosynthesis are briefly reviewed. The simplest model, based on standard cosmology and particle physics and assuming homogeneous baryon density at the relevant times, continues to stand up well. PMID:11607388

  1. On protein abundance distributions in complex mixtures

    PubMed Central

    2013-01-01

    Mass spectrometry, an analytical technique that measures the mass-to-charge ratio of ionized atoms or molecules, dates back more than 100 years, and has both qualitative and quantitative uses for determining chemical and structural information. Quantitative proteomic mass spectrometry on biological samples focuses on identifying the proteins present in the samples, and establishing the relative abundances of those proteins. Such protein inventories create the opportunity to discover novel biomarkers and disease targets. We have previously introduced a normalized, label-free method for quantification of protein abundances under a shotgun proteomics platform (Griffin et al., 2010). The introduction of this method for quantifying and comparing protein levels leads naturally to the issue of modeling protein abundances in individual samples. We here report that protein abundance levels from two recent proteomics experiments conducted by the authors can be adequately represented by Sichel distributions. Mathematically, Sichel distributions are mixtures of Poisson distributions with a rather complex mixing distribution, and have been previously and successfully applied to linguistics and species abundance data. The Sichel model can provide a direct measure of the heterogeneity of protein abundances, and can reveal protein abundance differences that simpler models fail to show. PMID:23360617

  2. Abundances of Elements in Stellar Coronae

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy

    1998-01-01

    Interest in stellar coronal abundances was piqued several years ago by the launch of satellites that were able to study the compositions of coronae on stars other than the sun. Motivated by the possibility that other stellar coronae might share the First Ionization Potential (FIP) Effect solar abundance anomaly, we have in recent years been attempting to determine coronal element abundances in other stars. I will review these results, together with similar results reported in the literature, from a critical perspective of understanding the true uncertainties involved in the measurements. The importance of element abundances for coronal physics will be highlighted, and it will be shown that the differences in the chemical compositions of active stars allow us to draw new conclusions regarding the nature of stellar coronae and coronal heating.

  3. 76 FR 37827 - Notice of Proposed Audit Delegation Renewals for the States of Oklahoma and Montana

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... Office of Natural Resources Revenue Notice of Proposed Audit Delegation Renewals for the States of...' proposals for audit delegation renewals. SUMMARY: The States of Oklahoma and Montana (States) are requesting that the Office of Natural Resources Revenue (ONRR) renew current delegations of audit...

  4. Absolute isotopic abundances of TI in meteorites

    NASA Astrophysics Data System (ADS)

    Niederer, F. R.; Papanastassiou, D. A.; Wasserburg, G. J.

    1985-03-01

    The absolute isotope abundance of Ti has been determined in Ca-Al-rich inclusions from the Allende and Leoville meteorites and in samples of whole meteorites. The absolute Ti isotope abundances differ by a significant mass dependent isotope fractionation transformation from the previously reported abundances, which were normalized for fractionation using 46Ti/48Ti. Therefore, the absolute compositions define distinct nucleosynthetic components from those previously identified or reflect the existence of significant mass dependent isotope fractionation in nature. The authors provide a general formalism for determining the possible isotope compositions of the exotic Ti from the measured composition, for different values of isotope fractionation in nature and for different mixing ratios of the exotic and normal components.

  5. Solar abundance of iridium

    PubMed Central

    Drake, Stephen; Aller, Lawrence H.

    1976-01-01

    By a method of spectrum synthesis, which yields log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance, an attempt is made to deduce the solar iridium abundance from one relatively unblended, but fairly weak IrI line, λ 3220.78 Å. If the Corliss-Bozman f-value for this line is adopted, we find log A(Ir) = 0.82 on the scale log A(H) = 12.00. The discordance with the value found from carbonaceous chondrites may arise from faulty f-values or from difficulties arising from line blending in this far ultraviolet domain of the solar spectrum. PMID:16578735

  6. Diterpenoid biopolymers: new directions for renewable materials engineering.

    PubMed

    Hillwig, Matthew L; Mann, Francis M; Peters, Reuben J

    2011-02-01

    Most types of ambers are naturally occurring, relatively hard, durable resinite polymers derived from the exudates of trees. This resource has been coveted for thousands of years due to its numerous useful properties in industrial processes, beauty, and purported medicinal properties. Labdane diterpenoid-based ambers represent the most abundant and important resinites on earth. These resinites are a dwindling nonrenewable natural resource, so a new source of such materials needs to be established. Recent advances in sequencing technologies and biochemical engineering are rapidly accelerating the rate of identifying and assigning function to genes involved in terpenoid biosynthesis, as well as producing industrial-scale quantities of desired small-molecules in bacteria and yeast. This has provided new tools for engineering metabolic pathways capable of producing diterpenoid monomers that will enable the production of custom-tailored resinite-like polymers. Furthermore, this biosynthetic toolbox is continuously expanding, providing new possibilities for renewing dwindling stocks of naturally occurring resinite materials and engineering new materials for future applications. PMID:20857504

  7. Origin of cosmic chemical abundances

    NASA Astrophysics Data System (ADS)

    Maio, Umberto; Tescari, Edoardo

    2015-11-01

    Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e-, H, H+, H-, He, He+, He++, D, D+, H2, H_2^+, HD, HeH+), gas cooling, star formation and production of heavy elements (C, N, O, Ne, Mg, Si, S, Ca, Fe, etc.) from stars covering a range of mass and metallicity are used to explore the origin of several chemical abundance patterns and to study both the metal and molecular content during simulated galaxy assembly. The resulting trends show a remarkable similarity to up-to-date observations of the most metal-poor damped Lyman α absorbers at redshift z ≳ 2. These exhibit a transient nature and represent collapsing gaseous structures captured while cooling is becoming effective in lowering the temperature below ˜ 104 K, before they are disrupted by episodes of star formation or tidal effects. Our theoretical results agree with the available data for typical elemental ratios, such as [C/O], [Si/Fe], [O/Fe], [Si/O], [Fe/H], [O/H] at redshifts z ˜ 2-7. Correlations between H I and H2 abundances show temporal and local variations and large spreads as a result of the increasing cosmic star formation activity from z ˜ 6 to 3. The scatter we find in the abundance ratios is compatible with the observational data and is explained by simultaneous enrichment by sources from different stellar phases or belonging to different stellar populations. Simulated synthetic spectra support the existence of metal-poor cold clumps with large optical depth at z ˜ 6 that could be potential Population III sites at low or intermediate redshift. The expected dust content is in line with recent determinations.

  8. Cationically polymerizable monomers derived from renewable sources

    SciTech Connect

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  9. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Hand, M.; Mai, T.

    2012-08-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It was presented in an Union of Concerned Scientists webinar on June 12, 2012.

  10. Renewing Urban Schools.

    ERIC Educational Resources Information Center

    Mayfield, John

    This paper describes an approach to urban renewal, called the Multi-Function Polis (MFP), which emphasizes education as a key factor in a renewal process that includes development of 21st century industries such as information technology, telecommunications, and environmental management. Focusing on Adelaide, Australia, as an example, the paper…

  11. Renewable Energy Technology

    ERIC Educational Resources Information Center

    Daugherty, Michael K.; Carter, Vinson R.

    2010-01-01

    In many ways the field of renewable energy technology is being introduced to a society that has little knowledge or background with anything beyond traditional exhaustible forms of energy and power. Dotson (2009) noted that the real challenge is to inform and educate the citizenry of the renewable energy potential through the development of…

  12. Renewable Energy in Alaska

    SciTech Connect

    Not Available

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  13. Renewing the Core Curriculum

    ERIC Educational Resources Information Center

    Lawson, Hal A.

    2007-01-01

    The core curriculum accompanied the development of the academic discipline with multiple names such as Kinesiology, Exercise and Sport Science, and Health and Human Performance. It provides commonalties for undergraduate majors. It is timely to renew this curriculum. Renewal involves strategic reappraisals. It may stimulate change or reaffirm the…

  14. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2012-08-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It was presented in a Power Systems Engineering Research Center webinar on September 4, 2012.

  15. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2012-08-01

    This presentation summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. This presentation was presented in a Wind Powering America webinar on August 15, 2012 and is now available through the Wind Powering America website.

  16. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Hand, M. M.

    2012-08-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It was presented in a webinar given by the California Energy Commission.

  17. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Hand, M.

    2012-10-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It is being presented at the Utility Variable-Generation Integration Group Fall Technical Workshop on October 24, 2012.

  18. Renewable Energy Annual

    EIA Publications

    2012-01-01

    Presents five chapters covering various aspects of the renewable energy marketplace, along with detailed data tables and graphics. Particular focus is given to renewable energy trends in consumption and electricity; manufacturing activities of solar thermal collectors, solar photovoltaic cells/modules, and geothermal heat pumps; and green pricing and net metering programs. The Department of Energy provides detailed offshore

  19. Colorado's Prospects for Interstate Commerce in Renewable Power

    SciTech Connect

    Hurlbut, D. J.

    2009-12-01

    Colorado has more renewable energy potential than it is ever likely to need for its own in-state electricity consumption. Such abundance may suggest an opportunity for the state to sell renewable power elsewhere, but Colorado faces considerable competition from other western states that may have better resources and easier access to key markets on the West Coast. This report examines factors that will be important to the development of interstate commerce for electricity generated from renewable resources. It examines market fundamentals in a regional context, and then looks at the implications for Colorado.

  20. Element abundances of classical novae

    NASA Astrophysics Data System (ADS)

    Andrea, J.; Drechsel, H.; Starrfield, S.

    1994-11-01

    Physical conditions and element abundances in the optically thin shells of 11 classical novae with outbursts between 1978 and 1989 were determined from an analysis of UV and optical spectra obtained during the nebular stage. Eight novae were studied on the basis of new optical and UV spectra. The accuracy of the element abundances depends on whether or not simultaneous UV spectra were available to determine individual ionization stage dependent gas temperatures. Generally, slightly higher than solar abundances of helium and pronounced overabundances of the heavier elements were found. QU Vul turned out to be an ONeMg nova, while the other objects belong to the class of CO novae. The nature of V2214 Oph could not be completely clarified. The novae V1668 Cyg (1978), V693 CrA (1981), and V1370 Aql (1982), for which published element abundances exist, were reanalyzed to check the consistency of our spectral analysis approach. Satisfactory agreement of the results was found. Photoionization calculations were carried out for PW Vul using the code of Aldrovandi, Pequignot, and Stasinska. A synthetic spectrum was generated for the parameters derived from the analysis of the UV and optical spectra, which is in very good agreement with the observations. The spectral analysis technique was then applied to the model spectrum and reproduced the model parameters well. Electron temperatures for the C(2+) and C(3+) ions between 7 500 and 12,000 K and for N(4+) betwen 12,000 and 16,000 K were derived. For PW Vul these temperatures remained relatively constant over several months. The decline in density of the ejected shells with time could be investigated for V842 Cen, QV Vul, V977 Sco, and V443 Sct, and was found to deviate from the relation Ne proportional to t-2 for free expansion of a shell in a different way for each object. A possible explanation may be the complex density structure of the shells. This suspicion is supported by high resolution spectra (ESO 3.6m telescope

  1. Renewable Electricity: Insights for the Coming Decade

    SciTech Connect

    Stark, C.; Pless, J.; Logan, J.; Zhou, E.; Arent, D. J.

    2015-02-01

    A sophisticated set of renewable electricity (RE) generation technologies is now commercially available. Globally, RE captured approximately half of all capacity additions since 2011. The cost of RE is already competitive with fossil fuels in some areas around the world, and prices are anticipated to continue to decline over the next decade. RE options, led by wind and solar, are part of a suite of technologies and business solutions that are transforming electricity sectors around the world. Renewable deployment is expected to continue due to: increasingly competitive economics; favorable environmental characteristics such as low water use, and minimal local air pollution and greenhouse gas (GHG) emissions; complementary risk profiles when paired with natural gas generators; strong support from stakeholders. Despite this positive outlook for renewables, the collapse in global oil prices since mid-2014 and continued growth in natural gas supply in the United States--due to the development of low-cost shale gas--raise questions about the potential impacts of fossil fuel prices on RE. Today, oil plays a very minor role in the electricity sectors of most countries, so direct impacts on RE are likely to be minimal (except where natural gas prices are indexed on oil). Natural gas and RE generating options appear to be more serious competitors than oil and renewables. Low gas prices raise the hurdle for RE to be cost competitive. Additionally, although RE emits far less GHG than natural gas, both natural gas and RE offer the benefits of reducing carbon relative to coal and oil (see Section 4.1 for more detail on the GHG intensity of electricity technologies). However, many investors and decision makers are becoming aware of the complementary benefits of pairing natural gas and renewables to minimize risk of unstable fuel prices and maintain the reliability of electricity to the grid.

  2. A Renewed Search for Elusive Lunar Granophyres

    NASA Technical Reports Server (NTRS)

    Mills, R. D.; Ross, D. K.; Simon, J. I.; Irving, A. J.

    2013-01-01

    Recent remote sensing studies [e.g., 1-3] indicate that several un-sampled regions of the Moon have significantly higher concentrations of silicic material (also high in [K], [U], and [Th]) than sampled regions. Within these areas are morphological features that are best explained by the existence of chemically evolved volcanic rocks. Observations of silicic domes [e.g., 1-5] suggest that sizable networks of silicic melt were present during crust-formation. Because of these recent findings there is a renewed interest in the petrogenesis of lunar, felsic igneous rocks. Specific questions are: (1) when were these magmas generated?, and (2) what was the source material? The two main hypotheses for generating silicic melts on Earth are fractional crystallization or partial melting of preexisting crust. On the Moon silicic melts are thought to have been generated during extreme fractional crystallization involving end-stage silicate liquid immiscibility (SLI) [e.g. 6, 7]. However, SLI cannot account for the production of significant volumes of silicic melt and its wide distribution, as reported by the remote global surveys [1, 2, 3]. In addition, experimental and natural products of SLI show that U and Th, which are abundant in the lunar granites and seen in the remote sensing data of the domes, are preferentially partitioned into the depolymerized ferrobasaltic magma and not the silicic portion [8, 9]. If SLI is not the mechanism that generated silicic magmas on the Moon then alternative processes such as fractional crystallization (only crystal-liquid separation) or partial melting should be considered as viable possibilities to be tested.

  3. Programs in Renewable Energy

    NASA Astrophysics Data System (ADS)

    1990-01-01

    Our nation faces significant challenges as we enter the 1990s: securing a reliable supply of competitively priced energy, improving the quality of our environment, and increasing our share of foreign markets for goods and services. The U.S. Department of Energy's (DOE) Programs in Renewable Energy are working toward meeting these challenges by developing the technologies that make use of our nation's largest energy resource: renewable energy. The sunlight, wind biomass, flowing water, ocean energy, and geothermal energy that make up the renewable energy resource can be found throughout our nation. These resources can provide all the forms of energy our nation needs: liquid fuels, electricity, and heating and cooling. Renewable energy meets about 10 percent of our need for these forms of energy today, yet the potential contribution is many times greater. DOE's Programs in Renewable Energy are working side-by-side with American industry to develop the technologies that convert renewable energy resources into practical, cost-competitive energy. After a decade of progress in research, several of these technologies are poised to make large contributions during the 1990s and beyond. This booklet provides an overview of the renewable energy programs and their plans for FY 1990. Sources of additional information are listed at the back of the booklet.

  4. Programs in Renewable Energy

    SciTech Connect

    Not Available

    1990-01-01

    Our nation faces significant challenges as we enter the 1990s: securing a reliable supply of competitively priced energy, improving the quality of our environment, and increasing our share of foreign markets for goods and services. The US Department of Energy's (DOE) Programs in Renewable Energy are working toward meeting these challenges by developing the technologies that make use of our nation's largest energy resource: renewable energy. The sunlight, wind biomass, flowing water, ocean energy, and geothermal energy that make up the renewable energy resource can be found throughout our nation. These resources can provide all the forms of energy our nation needs: liquid fuels, electricity, and heating and cooling. Renewable energy meets about 10% of our need for these forms of energy today, yet the potential contribution is many times greater. DOE's Programs in Renewable Energy are working side-by-side with American industry to develop the technologies that convert renewable energy resources into practical, cost-competitive energy. After a decade of progress in research, several of these technologies are poised to make large contributions during the 1990s and beyond. This booklet provides an overview of the renewable energy programs and their plans for FY 1990. Sources of additional information are listed at the back of the booklet. 48 figs., 4 tabs.

  5. Abundance of field galaxies

    NASA Astrophysics Data System (ADS)

    Klypin, Anatoly; Karachentsev, Igor; Makarov, Dmitry; Nasonova, Olga

    2015-12-01

    We present new measurements of the abundance of galaxies with a given circular velocity in the Local Volume: a region centred on the Milky Way Galaxy and extending to distance ˜10 Mpc. The sample of ˜750 mostly dwarf galaxies provides a unique opportunity to study the abundance and properties of galaxies down to absolute magnitudes MB ≈ -10 and virial masses M_vir= 109{ M_{⊙}}. We find that the standard Λ cold dark matter (ΛCDM) model gives remarkably accurate estimates for the velocity function of galaxies with circular velocities V ≳ 70 kms-1 and corresponding virial masses M_vir≳ 5× 10^{10}{ M_{⊙}}, but it badly fails by overpredicting ˜5 times the abundance of large dwarfs with velocities V = 30-40 kms-1. The warm dark matter (WDM) models cannot explain the data either, regardless of mass of WDM particle. Just as in previous observational studies, we find a shallow asymptotic slope dN/dlog V ∝ Vα, α ≈ -1 of the velocity function, which is inconsistent with the standard ΛCDM model that predicts the slope α = -3. Though reminiscent to the known overabundance of satellite problem, the overabundance of field galaxies is a much more difficult problem. For the standard ΛCDM model to survive, in the 10 Mpc radius of the Milky Way there should be 1000 not yet detected galaxies with virial mass M_vir≈ 10^{10}{ M_{⊙}}, extremely low surface brightness and no detectable H I gas. So far none of this type of galaxies have been discovered.

  6. Late embryogenesis abundant proteins

    PubMed Central

    Olvera-Carrillo, Yadira; Reyes, José Luis

    2011-01-01

    Late Embryogenesis Abundant (LEA) proteins accumulate at the onset of seed desiccation and in response to water deficit in vegetative plant tissues. The typical LEA proteins are highly hydrophilic and intrinsically unstructured. They have been classified in different families, each one showing distinctive conserved motifs. In this manuscript we present and discuss some of the recent findings regarding their role in plant adaptation to water deficit, as well as those concerning to their possible function, and how it can be related to their intrinsic structural flexibility. PMID:21447997

  7. Flare Plasma Iron Abundance

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Dan, Chau; Jain, Rajmal; Schwartz, Richard A.; Tolbert, Anne K.

    2008-01-01

    The equivalent width of the iron-line complex at 6.7 keV seen in flare X-ray spectra suggests that the iron abundance of the hottest plasma at temperatures >approx.10 MK may sometimes be significantly lower than the nominal coronal abundance of four times the photospheric value that is commonly assumed. This conclusion is based on X-ray spectral observations of several flares seen in common with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Solar X-ray Spectrometer (SOXS) on the second Indian geostationary satellite, GSAT-2. The implications of this will be discussed as it relates to the origin of the hot flare plasma - either plasma already in the corona that is directly heated during the flare energy release process or chromospheric plasma that is heated by flare-accelerated particles and driven up into the corona. Other possible explanations of lower-than-expected equivalent widths of the iron-line complex will also be discussed.

  8. 77 FR 22799 - Royalty Policy Committee (RPC) Notice of Renewal

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... Royalty Policy Committee (RPC) Notice of Renewal AGENCY: Office of Natural Resources Revenue, Interior. ACTION: Notice of renewal of the Royalty Policy Committee. SUMMARY: Following consultation with the... mineral and energy-related policies, and provide a forum to convey views representative of mineral...

  9. When Words Find Their Meaning: Renewal Versus Reform.

    ERIC Educational Resources Information Center

    Soder, Roger

    1999-01-01

    Serves as an introduction to seven articles which focus on the differences between school renewal and school reform and their implications in a democratic society. Embedded in both terms are basic views of the world, human nature, and the way individuals do business. Renewal considers matters of justice, equity, and diversity; reform affirms…

  10. Renewable Energy: Energy Security and Sustainability

    NASA Astrophysics Data System (ADS)

    Turner, John

    2002-03-01

    Renewable energy offers the possibility of providing a complete, sustainable energy infrastructure without anthropogenic emission of CO2. Large-scale implementation of renewable technologies would eliminate the need to develop and implement sequestration systems, by reducing the use of, and ultimately eliminating fossil based energy production. Renewable energy also offers energy security because indigenous resources are sufficient. The major renewable energy systems include phovoltaics (solar cells), solar thermal (electric and thermal), wind, biomass (plants and trees), hydroelectric, ocean, and geothermal. Given the intermittent nature of solar energy, only those energy systems that are coupled to an energy storage technology will be viable. Among the energy storage technologies are hydrogen, batteries, flywheels, superconductivity, ultracapacitors, pumped hydro, molten salts (for thermal storage), and compressed gas. One of the most versatile energy storage systems and the best energy carrier for transportation is hydrogen. This talk will review some of the basic renewable energy systems, present possible pathways for the implementation of hydrogen into the energy infrastructure and offer research areas that need to be addressed to increase the viability of these renewable energy technologies.

  11. Renewable transportation technologies

    SciTech Connect

    Bull, S.R.

    1995-12-31

    The need for alternative and renewable transportation fuels continues to be high on the nation`s agenda. Substituting these fuels for petroleum can reduce dependence on foreign oil imports, improve air quality, and mitigate greenhouse gases. Renewable fuels offer the same advantages as nonrenewable alternative fuels, and, in addition, provide an inexhaustible supply. The largest potential for significant quantities of liquid renewable fuels is from the production of biofuels from cellulosic biomass such as wastes and energy crops. Advanced vehicles will provide dramatic fuel efficiency improvements and will likely have electric drive systems. An evolution of vehicles is expected to occur, beginning with an electric vehicle that fills niche markets in the near term, to hybrid vehicles by the year 2000, to fuel cell vehicles after the year 2005. With the combination of renewable fuels and high efficiency, advanced vehicles can move the nation toward a sustainable transportation system.

  12. Renewable Energy for the Next Generation

    ERIC Educational Resources Information Center

    Barton, Leslie

    2005-01-01

    Renewable energy is harnessed from natural and sustainable sources, like wind, sun and water. They offer a pollution-free, endless source of electricity that is crucial in the fight against climate change. Every unit of this "green" electricity directly replaces electricity normally generated from conventional polluting sources such as coal or…

  13. Renewable Substitutability Index: Maximizing Renewable Resource Use in Buildings

    EPA Science Inventory

    In order to achieve a material and energy balance in buildings that is sustainable in the long run, there is an urgent need to assess the renewable and non-renewable resources used in the manufacturing process and to progressively replace non-renewable resources with renewables. ...

  14. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Hand, M. M.

    2012-08-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It was presented to the 2012 Western Conference of Public Service Commissioners, during their June, 2012, meeting. The Western Conference of Public Service Commissioners is a regional association within the National Association of Regulatory Utility Commissioners (NARUC).

  15. Financing renewable energy for Village Power application

    SciTech Connect

    Santibanez-Yeneza, G.

    1997-12-01

    When one talks of rural development, no doubt, the issue of rural energy is not far behind. As a significant component of any development strategy, rural energy is seen as the engine for growth that can bring about economic upliftment in the countryside. Many approaches to rural energy development have been tried. These approaches differ from country to country. But regardless of structure and approach, the goal remain essentially the same: to provide rural communities access to reliable energy services at affordable prices. In recent years, as global concern for the environment has increased, many governments have turned to renewable energy as a more environment friendly alternative to rural electrification. Technological advances in renewable energy application has helped to encourage this use. System reliability has improved, development costs have, to some extent been brought down and varied application approaches have been tried and tested in many areas. Indeed, there is huge potential for the development of renewable energy in the rural areas of most developing countries. At the rural level, renewable energy resources are almost always abundantly available: woodwaste, agricultural residues, animal waste, small-scale hydro, wind, solar and even sometimes geothermal resources. Since smaller scale systems are usually expected in these areas, renewable energy technologies can very well serve as decentralized energy systems for rural application. And not only for rural applications, new expansion planning paradigms have likewise led to the emergence of decentralized energy systems not only as supply options but also as corrective measures for maintaining end of line voltage levels. On the other hand, where renewable energy resource can provide significant blocks of power, they can be relied upon to provide indigenous power to the grids.

  16. Oxygen abundance and convection

    NASA Astrophysics Data System (ADS)

    Van't Veer, C.; Cayrel, R.

    The triplet IR lines of O I near 777 nm are computed with the Kurucz's code, modified to accept several convection models. The program has been run with the MLT algorithm, with l/H = 1.25 and 0.5, and with the Canuto-Mazzitelli and Canuto-Goldman-Mazzitelli approaches, on a metal-poor turnoff-star model atmosphere with Teff=6200 K, log g = 4.3, [Fe/H]= -1.5. The results show that the differences in equivalent widths for the 4 cases do not exceed 2 per cent (0.3 mA). The convection treatment is therefore not an issue for the oxygen abundance derived from the permitted lines.

  17. 2011 Renewable Energy Data Book

    SciTech Connect

    R. Gelman

    2013-02-01

    This Renewable Energy Data Book for 2011 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  18. 2014 Renewable Energy Data Book

    SciTech Connect

    Beiter, Philipp

    2015-11-15

    The Renewable Energy Data Book for 2014 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  19. 2014 Renewable Energy Data Book

    SciTech Connect

    Beiter, Philipp

    2015-11-01

    The Renewable Energy Data Book for 2014 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  20. 2009 Renewable Energy Data Book

    SciTech Connect

    Gelman, Rachel

    2010-08-01

    This Renewable Energy Data Book for 2009 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced waterpower, hydrogen, renewable fuels, and clean energy investments.

  1. 2008 Renewable Energy Data Book

    SciTech Connect

    Gelman, Rachel

    2009-07-01

    This Renewable Energy Data Book for 2008 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced waterpower, hydrogen, renewable fuels, and clean energy investments.

  2. 2010 Renewable Energy Data Book

    SciTech Connect

    Gelman, Rachel

    2011-10-01

    This Renewable Energy Data Book for 2010 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced waterpower, hydrogen, renewable fuels, and clean energy investments.

  3. 2008 Renewable Energy Data Book

    SciTech Connect

    Not Available

    2009-07-01

    This Renewable Energy Data Book for 2008 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  4. Renewable Energy: Solar Fuels GRC and GRS

    SciTech Connect

    Nathan Lewis Nancy Ryan Gray

    2010-02-26

    This Gordon Research Conference seeks to bring together chemists, physicists, materials scientists and biologists to address perhaps the outstanding technical problem of the 21st Century - the efficient, and ultimately economical, storage of energy from carbon-neutral sources. Such an advance would deliver a renewable, environmentally benign energy source for the future. A great technological challenge facing our global future is energy. The generation of energy, the security of its supply, and the environmental consequences of its use are among the world's foremost geopolitical concerns. Fossil fuels - coal, natural gas, and petroleum - supply approximately 90% of the energy consumed today by industrialized nations. An increase in energy supply is vitally needed to bring electric power to the 25% of the world's population that lacks it, to support the industrialization of developing nations, and to sustain economic growth in developed countries. On the geopolitical front, insuring an adequate energy supply is a major security issue for the world, and its importance will grow in proportion to the singular dependence on oil as a primary energy source. Yet, the current approach to energy supply, that of increased fossil fuel exploration coupled with energy conservation, is not scaleable to meet future demands. Rising living standards of a growing world population will cause global energy consumption to increase significantly. Estimates indicate that energy consumption will increase at least two-fold, from our current burn rate of 12.8 TW to 28 - 35 TW by 2050. - U.N. projections indicate that meeting global energy demand in a sustainable fashion by the year 2050 will require a significant fraction of the energy supply to come carbon free sources to stabilize atmospheric carbon dioxide levels at twice the pre-anthropogenic levels. External factors of economy, environment, and security dictate that this global energy need be met by renewable and sustainable sources

  5. Synthesis of renewable bisphenols from creosol.

    PubMed

    Meylemans, Heather A; Groshens, Thomas J; Harvey, Benjamin G

    2012-01-01

    A series of renewable bisphenols has been synthesized from creosol (2-methoxy-4-methylphenol) through stoichiometric condensation with short-chain aldehydes. Creosol can be readily produced from lignin, potentially allowing for the large scale synthesis of bisphenol A replacements from abundant waste biomass. The renewable bisphenols were isolated in good yields and purities without resorting to solvent-intense purification methods. Zinc acetate was shown to be a selective catalyst for the ortho-coupling of formaldehyde, but was unreactive when more sterically demanding aldehydes were used. Dilute HCl and HBr solutions were shown to be effective catalysts for the selective coupling of aldehydes in the position meta to the hydroxyl group. The acid solutions could be recycled and reused multiple times without decrease in activity or yield. PMID:22162446

  6. Actinide abundances in ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Hagee, B.; Bernatowicz, T. J.; Podosek, F. A.; Johnson, M. L.; Burnett, D. S.

    1990-01-01

    Measurements of actinide and light REE (LREE) abundances and of phosphate abundances in equilibrated ordinary chondrites were obtained and were used to define the Pu abundance in the solar system and to determine the degree of variation of actinide and LREE abundances. The results were also used to compare directly the Pu/U ratio with the earlier obtained ratio determined indirectly, as (Pu/Nd)x(Nd/U), assuming that Pu behaves chemically as a LREE. The data, combined with high-accuracy isotope-dilution data from the literature, show that the degree of gram-scale variability of the Th, U, and LREE abundances for equilibrated ordinary chondrites is a factor of 2-3 for absolute abundances and up to 50 percent for relative abundances. The observed variations are interpreted as reflecting the differences in the compositions and/or proportions of solar nebula components accreted to ordinary chondrite parent bodies.

  7. Integrating Variable Renewable Energy: Challenges and Solutions

    SciTech Connect

    Bird, L.; Milligan, M.; Lew, D.

    2013-09-01

    In the U.S., a number of utilities are adopting higher penetrations of renewables, driven in part by state policies. While power systems have been designed to handle the variable nature of loads, the additional supply-side variability and uncertainty can pose new challenges for utilities and system operators. However, a variety of operational and technical solutions exist to help integrate higher penetrations of wind and solar generation. This paper explores renewable energy integration challenges and mitigation strategies that have been implemented in the U.S. and internationally, including forecasting, demand response, flexible generation, larger balancing areas or balancing area cooperation, and operational practices such as fast scheduling and dispatch.

  8. Capella: Structure and Abundances

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy S.

    1999-01-01

    This grant covers the analysis of EUVE spectra of the cool star binary system Capella. This project has also required the analysis of simultaneous Advanced Satellite for Cosmology and Astrophysics (ASCA) data. The ASCA spectrum of Capella could not be fit with standard models; by imposing models based on strong lines observed with EUVE, a problem wavelength region was identified. Correcting the problem required calculations of atomic collision strengths of higher principal quantum number than had ever been calculated. With these new models applied to the ASCA spectrum, better fits were obtained. Findings are that: (1) ASCA and EUVE spectra are both dominated by a region at 6 x 10(exp 6) K. (2) The high energy cut-off of the ASCA spectrum is consistent with emission from the highest ionization stages of EUVE, namely Fe XXIV. (3) EUVE requires a continuous emission measure distribution with more than two temperatures. (4) The ASCA spectra are of such high statistical significance that systematic uncertainties dominate, including atomic physics issues and calibration issues. (5) While the ASCA spectral fits achieve lower Chi(exp 2 with two-temperature fits, the EUVE-derived emission measure distribution models are also consistent with the spectra. (6) The Fe/H ratio obtained from the ASCA fit is within 20 % of the Fe/H abundance obtained from the summed spectra of Capella over 5 EUVE pointings, as well as the 1996 EUVE data. This result confirms our claims that quasi-continua composed of weak emission lines in the short wavelength spectrometer of EUVE are not major contributors to the measured Capella continuum. Other abundance ratios are also determined from the ASCA data, using models derived with EUVE. Si, Si, and Mg appear to be close to solar photospheric values, while the ratio of Ne/Fe is three to four times lower than solar photospheric values. Whether there is a general First Ionization Potential (FIP) effect or a specific neon anomaly cannot be determined

  9. Integrated renewable energy networks

    NASA Astrophysics Data System (ADS)

    Mansouri Kouhestani, F.; Byrne, J. M.; Hazendonk, P.; Brown, M. B.; Spencer, L.

    2015-12-01

    This multidisciplinary research is focused on studying implementation of diverse renewable energy networks. Our modern economy now depends heavily on large-scale, energy-intensive technologies. A transition to low carbon, renewable sources of energy is needed. We will develop a procedure for designing and analyzing renewable energy systems based on the magnitude, distribution, temporal characteristics, reliability and costs of the various renewable resources (including biomass waste streams) in combination with various measures to control the magnitude and timing of energy demand. The southern Canadian prairies are an ideal location for developing renewable energy networks. The region is blessed with steady, westerly winds and bright sunshine for more hours annually than Houston Texas. Extensive irrigation agriculture provides huge waste streams that can be processed biologically and chemically to create a range of biofuels. The first stage involves mapping existing energy and waste flows on a neighbourhood, municipal, and regional level. Optimal sites and combinations of sites for solar and wind electrical generation, such as ridges, rooftops and valley walls, will be identified. Geomatics based site and grid analyses will identify best locations for energy production based on efficient production and connectivity to regional grids.

  10. Renewable Electricity Futures (Presentation)

    SciTech Connect

    Mai, T.

    2012-08-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It was presented at the 2012 RE AMP Annual Meeting. RE-AMP is an active network of 144 nonprofits and foundations across eight Midwestern states working on climate change and energy policy with the goal of reducing global warming pollution economy-wide 80% by 2050.

  11. Renewable Electricity Futures (Presentation)

    SciTech Connect

    DeMeo, E.

    2012-08-01

    This presentation library summarizes findings of NREL's Renewable Electricity Futures study, published in June 2012. RE Futures investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. It was presented at Wind Powering America States Summit. The Summit, which follows the American Wind Energy Association's (AWEA's) annual WINDPOWER Conference and Exhibition, provides state Wind Working Groups, state energy officials, U.S. Energy Department and national laboratory representatives, and professional and institutional partners an opportunity to review successes, opportunities, and challenges for wind energy and plan future collaboration.

  12. Development of Electricity Generation from Renewable Energy Sources in Turkey

    NASA Astrophysics Data System (ADS)

    Kentel, E.

    2011-12-01

    Electricity is mainly produced from coal, natural gas and hydropower in Turkey. However, almost all the natural gas and high quality coal are imported. Thus, increasing the shares of both hydro and other renewables in energy supply is necessary to decrease dependency of the country on foreign sources. In 2008, the total installed capacity of Turkey was around 42000 MW and 66 % of this was from thermal sources. The remaining 33 % was from hydro, which leaves only one percent for the other renewable energy sources. The share of renewable energy in the energy budget of Turkey has increased in the last two decades; however, in 2008, only 17 % of the total electricity generation was realized from renewable sources most of which was hydro. According to State Hydraulic Works (SHW) which is the primary executive state agency responsible for the planning, operating and managing of Turkey's water resources, Turkey utilizes only around 35% of its economically viable hydro potential. The current situation clearly demonstrates the need for increasing the share of renewables in the energy budget. New laws, such as the Electricity Market Law, have been enacted and the following items were identified by the Ministry of Energy and Natural Resources of Turkey among primary energy policies and priorities: (i) decreasing dependency on foreign resources by prioritizing utilization of natural resources, (ii) increasing the share of renewable energy resources in the energy budget of Turkey; (iii) minimization of adverse environmental impacts of production and utilization of natural resources. The government's energy policy increased investments in renewable energy resources; however lack of a needed legal framework brought various environmental and social problems with this fast development. The development of the share of renewable resources in the energy budget, current government policy, and environmental concerns related with renewables, and ideas to improve the overall benefits of

  13. Abundances in dwarf irregular galaxies

    NASA Technical Reports Server (NTRS)

    Dufour, Reginald J.

    1986-01-01

    The results of abundance studies of dwarf irregular galaxies and similar objects are reviewed with special attention to variations in the CNO element group. Observations of the forbidden N II and semiforbidden C III lines in the most metal-poor galaxy known, IZw 18, are presented for the first time and CNO abundances are derived via a photoionization model and discussed in the context of the abundances found in other metal-poor H II regions and galaxies.

  14. Renewable liquid reflection grating

    DOEpatents

    Ryutov, Dmitri D.; Toor, Arthur

    2003-10-07

    A renewable liquid reflection grating. Electrodes are operatively connected to a conducting liquid in an arrangement that produces a reflection grating and driven by a current with a resonance frequency. In another embodiment, the electrodes create the grating by a resonant electrostatic force acting on a dielectric liquid.

  15. Challenges measuring cardiomyocyte renewal

    PubMed Central

    Soonpaa, Mark H.; Rubart, Michael; Field, Loren J.

    2012-01-01

    Interventions to effect therapeutic cardiomyocyte renewal have received considerable interest of late. Such interventions, if successful, could give rise to myocardial regeneration in diseased hearts. Regenerative interventions fall into two broad categories, namely approaches based on promoting renewal of pre-existing cardiomyocytes and approaches based on cardiomyogenic stem cell activity. The latter category can be further subdivided into approaches promoting differentiation of endogenous cardiomyogenic stem cells, approaches wherein cardiomyogenic stem cells are harvested, amplified or enriched ex vivo, and subsequently engrafted into the heart, and approaches wherein an exogenous stem cell is induced to differentiate in vitro, and the resulting cardiomyocytes are engrafted into the heart. There is disagreement in the literature regarding the degree to which cardiomyocyte renewal occurs in the normal and injured heart, the mechanism(s) by which this occurs, and the degree to which therapeutic interventions can enhance regenerative growth. This review discusses several caveats which are encountered when attempting to measure cardiomyocyte renewal in vivo which likely contribute, at least in part, to the disagreement regarding the levels at which this occurs in normal, injured and treated hearts. PMID:23142641

  16. Renew, Reflect, and Refresh

    ERIC Educational Resources Information Center

    Texley, Juliana

    2005-01-01

    Is that the sound of the last bus leaving the schoolyard? Or the staff's collective sigh of relief? School's out. Now it's time to nurture the lifelong learner deep inside with a summer reading list that will allow teachers to renew, reflect, and refresh. The National Science Education Standards reminds us, "Becoming an effective science teacher…

  17. Sources of Renewal.

    ERIC Educational Resources Information Center

    Kohl, Herb

    1980-01-01

    Given the outside pressures of layoffs, inflation, and public criticism, many teachers are turning to the specifics of teaching for release. Talking with one's students, developing humor in the classroom, experimenting with a slower pace of life, and thinking about self-sufficiency can lead to renewed energy and interest. (Author/SJL)

  18. Biodiesel and renewable diesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is an alternative diesel fuel produced from vegetable oil, animal fats or waste oils. The process used in its production is known as transesterification. If vegetable oils or animal fats are subjected to a process similar for making diesel fuel derived from petroleum, a fuel called renew...

  19. Adhesives from renewable resources

    SciTech Connect

    Hemingway, R.W.; Conner, A.H. )

    1989-01-01

    This book shows that new alternatives based on renewable resources will be available should supplied of resins derived from petrochemicals become inadequate again. Opportunities for the development of high-value specialty polymers are highlighted by work presented on polymers derived from mollusks.

  20. Learning about Renewable Energy.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    This booklet provides an introduction to renewable energy, discussing: (1) the production of electricity from sunlight; (2) wind power; (3) hydroelectric power; (4) geothermal energy; and (5) biomass. Also provided are nine questions to answer (based on the readings), four additional questions to answer (which require additional information), and…

  1. Orchestrating Simultaneous Renewal.

    ERIC Educational Resources Information Center

    Theobald, Paul; Rochon, Ronald

    1999-01-01

    Orchestrating simultaneous renewal of schools and teacher education is possible in the presence of appropriate leadership, reformer diversity, program audits, accurate assessments, and a focus on the big picture. Public education is the glue that holds society together, not just a place where job skills are acquired. (MLH)

  2. Renewing Democracy in Schools.

    ERIC Educational Resources Information Center

    Noddings, Nel

    1999-01-01

    Unlike systemic/academic reforms, renewal programs identify democratic education's central purposes and processes, interpret them in contemporary terms, and seek to strengthen them. The uniform standards movement may handicap these efforts by eliminating many student choices and discouraging the rational political discussion underlying liberal…

  3. Hydrogen from renewable resources research

    SciTech Connect

    Takahashi, P.K.; McKinley, K.R.

    1990-07-01

    In 1986 the Hawaii Natural Energy Institute (HNEI) and the Florida Solar Energy Center (FSEC) were contracted by the Solar Energy Research Institute (SERI) to conduct an assessment of hydrogen production technologies and economic feasibilities of the production and use of hydrogen from renewable resources. In the 1989/90 period all monies were directed toward research and development with an emphasis on integration of tasks, focusing on two important issues, production and storage. The current year's efforts consisted of four tasks, one task containing three subtasks: Hydrogen Production by Gasification of Glucose and Wet Biomass in Supercritical Water; Photoelectrochemical Production of Hydrogen; Photoemission and Photoluminescence Studies of Catalyzed Photoelectrode Surfaces for Hydrogen Production; Solar Energy Chemical Conversion by Means of Photoelectrochemical (PEC) Methods Using Coated Silicon Electrodes; Assessment of Impedance Spectroscopy Methods for Evaluation of Semiconductor-Electrolyte Interfaces; Solar Energy Conversion with Cyanobacteria; Nonclassical Polyhydride Metal Complexes as Hydrogen Storage Materials. 61 refs., 22 figs., 11 tabs.

  4. Renewal equations for option pricing

    NASA Astrophysics Data System (ADS)

    Montero, M.

    2008-09-01

    In this paper we will develop a methodology for obtaining pricing expressions for financial instruments whose underlying asset can be described through a simple continuous-time random walk (CTRW) market model. Our approach is very natural to the issue because it is based in the use of renewal equations, and therefore it enhances the potential use of CTRW techniques in finance. We solve these equations for typical contract specifications, in a particular but exemplifying case. We also show how a formal general solution can be found for more exotic derivatives, and we compare prices for alternative models of the underlying. Finally, we recover the celebrated results for the Wiener process under certain limits.

  5. Renewable power sparks financial interest

    NASA Astrophysics Data System (ADS)

    Norman, C.

    1981-06-01

    A legal and economic assessment is given of section 210 of the Public Utility Regulatory Practices Act (PURPA) of 1978, which guarantees a market for small electrical power producers by requiring utilities to buy from them at premium rates and, in addition, exempts them from regulatory restrictions imposed on utilities. To qualify, small power producers are limited to a capacity of 80 MW at any one site, and they must use such renewable energy sources as wind, hydroelectric, biomass, solar, and waste products. There is no size limit for industrial cogeneration facilities, but those that burn oil or natural gas must meet efficiency standards to qualify. Section 210 has, however, been seriously challenged in the courts by utility companies viewing it as a Federal infringement of the right of States to regulate their utilities; a court ruling favorable to the utilities has already been given in Mississippi, and similar rulings are being sought in New York.

  6. Erratum: Interstellar Abundance Standards Revisited

    NASA Astrophysics Data System (ADS)

    Sofia, U. J.; Meyer, D. M.

    2001-09-01

    In the Letter ``Interstellar Abundance Standards Revisited'' by U. J. Sofia and D. M. Meyer (ApJ, 554, L221 [2001]), Table 2 and its footnotes contain several typographical errors. The corrected table is shown below. We note that the solar reference standard now implies a positive abundance of nitrogen in halo dust.

  7. Renewable Systems Interconnection: Executive Summary

    SciTech Connect

    Kroposki, B.; Margolis, R.; Kuswa, G.; Torres, J.; Bower, W.; Key, T.; Ton, D.

    2008-02-01

    The U.S. Department of Energy launched the Renewable Systems Interconnection (RSI) study in 2007 to address the challenges to high penetrations of distributed renewable energy technologies. The RSI study consists of 14 additional reports.

  8. Renewable liquid reflecting zone plate

    DOEpatents

    Toor, Arthur; Ryutov, Dmitri D.

    2003-12-09

    A renewable liquid reflecting zone plate. Electrodes are operatively connected to a dielectric liquid in a circular or other arrangement to produce a reflecting zone plate. A system for renewing the liquid uses a penetrable substrate.

  9. Nucleosynthesis: Stellar and Solar Abundances and Atomic Data

    NASA Technical Reports Server (NTRS)

    Cowan, John J.; Lawler, James E.; Sneden, Christopher; DenHartog, E. A.; Collier, Jason; Dodge, Homer L.

    2006-01-01

    Abundance observations indicate the presence of often surprisingly large amounts of neutron capture (i.e., s- and r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy the progenitors of the halo stars responsible for neutron-capture synthesis. Comparisons of abundance trends can be used to understand the chemical evolution of the Galaxy and the nature of heavy element nucleosynthesis. In addition age determinations, based upon long-lived radioactive nuclei abundances, can now be obtained. These stellar abundance determinations depend critically upon atomic data. Improved laboratory transition probabilities have been recently obtained for a number of elements. These new gf values have been used to greatly refine the abundances of neutron-capture elemental abundances in the solar photosphere and in very metal-poor Galactic halo stars. The newly determined stellar abundances are surprisingly consistent with a (relative) Solar System r-process pattern, and are also consistent with abundance predictions expected from such neutron-capture nucleosynthesis.

  10. Public opinion and communicative action around renewable energy projects

    NASA Astrophysics Data System (ADS)

    Fast, Stewart

    This thesis investigates how rural communities negotiate the development of renewable energy projects. Public and local community acceptance of these new technologies in rural areas around the world is uncertain and spatially uneven and represents an area of emerging public policy interest and one where scholarly theory is rapidly developing. This thesis uses Habermasian concepts of public sphere, communicative action and deliberative democracy, as well as the concept of "wicked problems" from the planning studies literature combined with geographical concepts of place and scale to advance theoretical and empirical understanding of how public opinion on renewable energy technologies is formed in place. It documents energy use patterns, attitudes and socio-political relations at a time when considerable state and business efforts are directed at the construction of solar, wind, biomass and small-hydro technologies in rural regions. These concepts and theories are applied in a case study of rural communities in the Eastern Ontario Highlands, an impoverished area undergoing rapid restructuring driven by centralization of services and amenity migration but with abundant natural resources in form of forests, numerous waterways and open space which have attracted a broad range of new energy developments. Overall high levels of support for alternative energy development particularly for solar power were found, albeit for reasons of local energy security and not for reasons of preventing climate change. There was some evidence that seasonal residents are less supportive of hydro and biomass projects than permanent residents possibly reflecting broader trends in rural economies away from productive uses of land to consumptive appreciation of rural landscapes. The thesis suggests that collective action to advance energy projects in the case study area require agreement along three world-claims (truth, rightness and truthfulness) and that communication leading to discourse

  11. Renewable energy and wildlife conservation

    USGS Publications Warehouse

    Khalil, Mona

    2016-01-01

    The renewable energy sector is rapidly expanding and diversifying the power supply of the country. Yet, as our Nation works to advance renewable energy and to conserve wildlife, some conflicts arise. To address these challenges, the U.S. Geological Survey (USGS) is conducting innovative research and developing workable solutions to reduce impacts of renewable energy production on wildlife.

  12. DRI Renewable Energy Center (REC) (NV)

    SciTech Connect

    Hoekman, S. Kent; Broch, Broch; Robbins, Curtis; Jacobson, Roger; Turner, Robert

    2012-12-31

    The primary objective of this project was to utilize a flexible, energy-efficient facility, called the DRI Renewable Energy Experimental Facility (REEF) to support various renewable energy research and development (R&D) efforts, along with education and outreach activities. The REEF itself consists of two separate buildings: (1) a 1200-ft2 off-grid capable house and (2) a 600-ft2 workshop/garage to support larger-scale experimental work. Numerous enhancements were made to DRI's existing renewable power generation systems, and several additional components were incorporated to support operation of the REEF House. The power demands of this house are satisfied by integrating and controlling PV arrays, solar thermal systems, wind turbines, an electrolyzer for renewable hydrogen production, a gaseous-fuel internal combustion engine/generator set, and other components. Cooling needs of the REEF House are satisfied by an absorption chiller, driven by solar thermal collectors. The REEF Workshop includes a unique, solar air collector system that is integrated into the roof structure. This system provides space heating inside the Workshop, as well as a hot water supply. The Workshop houses a custom-designed process development unit (PDU) that is used to convert woody biomass into a friable, hydrophobic char that has physical and chemical properties similar to low grade coal. Besides providing sufficient space for operation of this PDU, the REEF Workshop supplies hot water that is used in the biomass treatment process. The DRI-REEF serves as a working laboratory for evaluating and optimizing the performance of renewable energy components within an integrated, residential-like setting. The modular nature of the system allows for exploring alternative configurations and control strategies. This experimental test bed is also highly valuable as an education and outreach tool both in providing an infrastructure for student research projects, and in highlighting renewable energy

  13. Bolivia renewable energy development

    SciTech Connect

    Smith, P.

    1997-12-01

    The author summarizes changes which have occurred in Bolivia in the past year which have had an impact on renewable energy source development. Political changes have included the privatization of power generation and power distribution, and resulted in a new role for state level government and participation by the individual. A National Rural Electrification Plan was adopted in 1996, which stresses the use of GIS analysis and emphasizes factors such as off grid, economic index, population density, maintenance risk, and local organizational structure. The USAID program has chosen to stress economic development, environmental programs, and health over village power programs. The national renewables program has adopted a new development direction, with state projects, geothermal projects, and private sector involvement stressed.

  14. Renewable energy project development

    SciTech Connect

    Ohi, J.

    1996-12-31

    The author presents this paper with three main thrusts. The first is to discuss the implementation of renewable energy options in China, the second is to identify the key project development steps necessary to implement such programs, and finally is to develop recommendations in the form of key issues which must be addressed in developing such a program, and key technical assistance needs which must be addressed to make such a program practical.

  15. Non-Additive Effects of Genotypic Diversity Increase Floral Abundance and Abundance of Floral Visitors

    PubMed Central

    Genung, Mark A.; Lessard, Jean-Philippe; Brown, Claire B.; Bunn, Windy A.; Cregger, Melissa A.; Reynolds, Wm. Nicholas; Felker-Quinn, Emmi; Stevenson, Mary L.; Hartley, Amanda S.; Crutsinger, Gregory M.; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2010-01-01

    Background In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. Methodology/Principal Findings Using an experimental common garden that manipulated genotypic diversity (the number of distinct genotypes per plot) of Solidago altissima, we document that genotypic diversity of a dominant plant can indirectly influence flower visitor abundance. Across two years, we found that 1) plant genotype explained 45% and 92% of the variation in flower visitor abundance in 2007 and 2008, respectively; and 2) plant genotypic diversity had a positive and non-additive effect on floral abundance and the abundance of flower visitors, as plots established with multiple genotypes produced 25% more flowers and received 45% more flower visits than would be expected under an additive model. Conclusions/Significance These results provide evidence that declines in genotypic diversity may be an important but little considered factor for understanding plant-pollinator dynamics, with implications for the global decline in pollinators due to reduced plant diversity in both agricultural and natural ecosystems. PMID:20090850

  16. The boron abundance of Procyon

    NASA Technical Reports Server (NTRS)

    Lemke, Michael; Lambert, David L.; Edvardsson, Bengt

    1993-01-01

    The B I 2496.8 A resonance line and HST/GHRS echelle spectra are used with model atmospheres and synthetic spectra to derive the B abundance of the F dwarfs Procyon (Alpha Canis Minoris), Theta Ursae Majoris, and Iota Pegasi. The B abundance of Theta UMa and Iota Peg is similar to that derived by Boesgaard and Heacox (1978) from the B II resonance line in spectra of A- and B-type stars. These two dwarfs show normal abundances of Li, Be, and B. Procyon, which is highly depleted in Li and Be, is depleted in B by a factor of at least 3. Comparison of the spectra of Procyon and the halo dwarf HD 140283 shows that the B abundance assigned by Duncan et al. (1992) to three halo dwarfs is not greatly overestimated as a result of contamination of the B I line by an unidentified line.

  17. 78 FR 46404 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ... of Renewed Approval of Information Collection: Human Response to Aviation Noise in Protected Natural... Number: 2120-0744. Title: Human Response to Aviation Noise in Protected Natural Areas Survey....

  18. 78 FR 63561 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... of Renewed Approval of Information Collection: Human Response to Aviation Noise in Protected Natural.... Title: Human Response to Aviation Noise in Protected Natural Areas Survey. Form Numbers: There are...

  19. Literature survey of isotopic abundance data for 1987-1989

    SciTech Connect

    Holden, N.E. )

    1989-08-09

    I have compiled all of the data on isotopic abundance measurements and their variation in nature for the time period since the last General Assembly. Most of the data deals with the variations in the abundances as given by per mil deviations from some standard. As such, they are not of major interest to the Atomic Weights Commission. However, there were some measurements which are of general interest in this list.

  20. Regional Renewable Energy Cooperatives

    NASA Astrophysics Data System (ADS)

    Hazendonk, P.; Brown, M. B.; Byrne, J. M.; Harrison, T.; Mueller, R.; Peacock, K.; Usher, J.; Yalamova, R.; Kroebel, R.; Larsen, J.; McNaughton, R.

    2014-12-01

    We are building a multidisciplinary research program linking researchers in agriculture, business, earth science, engineering, humanities and social science. Our goal is to match renewable energy supply and reformed energy demands. The program will be focused on (i) understanding and modifying energy demand, (ii) design and implementation of diverse renewable energy networks. Geomatics technology will be used to map existing energy and waste flows on a neighbourhood, municipal, and regional level. Optimal sites and combinations of sites for solar and wind electrical generation (ridges, rooftops, valley walls) will be identified. Geomatics based site and grid analyses will identify best locations for energy production based on efficient production and connectivity to regional grids and transportation. Design of networks for utilization of waste streams of heat, water, animal and human waste for energy production will be investigated. Agriculture, cities and industry produce many waste streams that are not well utilized. Therefore, establishing a renewable energy resource mapping and planning program for electrical generation, waste heat and energy recovery, biomass collection, and biochar, biodiesel and syngas production is critical to regional energy optimization. Electrical storage and demand management are two priorities that will be investigated. Regional scale cooperatives may use electric vehicle batteries and innovations such as pump storage and concentrated solar molten salt heat storage for steam turbine electrical generation. Energy demand management is poorly explored in Canada and elsewhere - our homes and businesses operate on an unrestricted demand. Simple monitoring and energy demand-ranking software can easily reduce peaks demands and move lower ranked uses to non-peak periods, thereby reducing the grid size needed to meet peak demands. Peak demand strains the current energy grid capacity and often requires demand balancing projects and

  1. Climatic effects on mosquito abundance in Mediterranean wetlands

    PubMed Central

    2014-01-01

    Background The impact of climate change on vector-borne diseases is highly controversial. One of the principal points of debate is whether or not climate influences mosquito abundance, a key factor in disease transmission. Methods To test this hypothesis, we analysed ten years of data (2003–2012) from biweekly surveys to assess inter-annual and seasonal relationships between the abundance of seven mosquito species known to be pathogen vectors (West Nile virus, Usutu virus, dirofilariasis and Plasmodium sp.) and several climatic variables in two wetlands in SW Spain. Results Within-season abundance patterns were related to climatic variables (i.e. temperature, rainfall, tide heights, relative humidity and photoperiod) that varied according to the mosquito species in question. Rainfall during winter months was positively related to Culex pipiens and Ochlerotatus detritus annual abundances. Annual maximum temperatures were non-linearly related to annual Cx. pipiens abundance, while annual mean temperatures were positively related to annual Ochlerotatus caspius abundance. Finally, we modelled shifts in mosquito abundances using the A2 and B2 temperature and rainfall climate change scenarios for the period 2011–2100. While Oc. caspius, an important anthropophilic species, may increase in abundance, no changes are expected for Cx. pipiens or the salt-marsh mosquito Oc. detritus. Conclusions Our results highlight that the effects of climate are species-specific, place-specific and non-linear and that linear approaches will therefore overestimate the effect of climate change on mosquito abundances at high temperatures. Climate warming does not necessarily lead to an increase in mosquito abundance in natural Mediterranean wetlands and will affect, above all, species such as Oc. caspius whose numbers are not closely linked to rainfall and are influenced, rather, by local tidal patterns and temperatures. The final impact of changes in vector abundance on disease frequency

  2. How selection structures species abundance distributions

    PubMed Central

    Magurran, Anne E.; Henderson, Peter A.

    2012-01-01

    How do species divide resources to produce the characteristic species abundance distributions seen in nature? One way to resolve this problem is to examine how the biomass (or capacity) of the spatial guilds that combine to produce an abundance distribution is allocated among species. Here we argue that selection on body size varies across guilds occupying spatially distinct habitats. Using an exceptionally well-characterized estuarine fish community, we show that biomass is concentrated in large bodied species in guilds where habitat structure provides protection from predators, but not in those guilds associated with open habitats and where safety in numbers is a mechanism for reducing predation risk. We further demonstrate that while there is temporal turnover in the abundances and identities of species that comprise these guilds, guild rank order is conserved across our 30-year time series. These results demonstrate that ecological communities are not randomly assembled but can be decomposed into guilds where capacity is predictably allocated among species. PMID:22787020

  3. Metagenomics of the Svalbard reindeer rumen microbiome reveals abundance of polysaccharide utilization loci.

    PubMed

    Pope, Phillip B; Mackenzie, Alasdair K; Gregor, Ivan; Smith, Wendy; Sundset, Monica A; McHardy, Alice C; Morrison, Mark; Eijsink, Vincent G H

    2012-01-01

    Lignocellulosic biomass remains a largely untapped source of renewable energy predominantly due to its recalcitrance and an incomplete understanding of how this is overcome in nature. We present here a compositional and comparative analysis of metagenomic data pertaining to a natural biomass-converting ecosystem adapted to austere arctic nutritional conditions, namely the rumen microbiome of Svalbard reindeer (Rangifer tarandus platyrhynchus). Community analysis showed that deeply-branched cellulolytic lineages affiliated to the Bacteroidetes and Firmicutes are dominant, whilst sequence binning methods facilitated the assemblage of metagenomic sequence for a dominant and novel Bacteroidales clade (SRM-1). Analysis of unassembled metagenomic sequence as well as metabolic reconstruction of SRM-1 revealed the presence of multiple polysaccharide utilization loci-like systems (PULs) as well as members of more than 20 glycoside hydrolase and other carbohydrate-active enzyme families targeting various polysaccharides including cellulose, xylan and pectin. Functional screening of cloned metagenome fragments revealed high cellulolytic activity and an abundance of PULs that are rich in endoglucanases (GH5) but devoid of other common enzymes thought to be involved in cellulose degradation. Combining these results with known and partly re-evaluated metagenomic data strongly indicates that much like the human distal gut, the digestive system of herbivores harbours high numbers of deeply branched and as-yet uncultured members of the Bacteroidetes that depend on PUL-like systems for plant biomass degradation. PMID:22701672

  4. Metagenomics of the Svalbard Reindeer Rumen Microbiome Reveals Abundance of Polysaccharide Utilization Loci

    PubMed Central

    Pope, Phillip B.; Mackenzie, Alasdair K.; Gregor, Ivan; Smith, Wendy; Sundset, Monica A.; McHardy, Alice C.; Morrison, Mark; Eijsink, Vincent G.H.

    2012-01-01

    Lignocellulosic biomass remains a largely untapped source of renewable energy predominantly due to its recalcitrance and an incomplete understanding of how this is overcome in nature. We present here a compositional and comparative analysis of metagenomic data pertaining to a natural biomass-converting ecosystem adapted to austere arctic nutritional conditions, namely the rumen microbiome of Svalbard reindeer (Rangifer tarandus platyrhynchus). Community analysis showed that deeply-branched cellulolytic lineages affiliated to the Bacteroidetes and Firmicutes are dominant, whilst sequence binning methods facilitated the assemblage of metagenomic sequence for a dominant and novel Bacteroidales clade (SRM-1). Analysis of unassembled metagenomic sequence as well as metabolic reconstruction of SRM-1 revealed the presence of multiple polysaccharide utilization loci-like systems (PULs) as well as members of more than 20 glycoside hydrolase and other carbohydrate-active enzyme families targeting various polysaccharides including cellulose, xylan and pectin. Functional screening of cloned metagenome fragments revealed high cellulolytic activity and an abundance of PULs that are rich in endoglucanases (GH5) but devoid of other common enzymes thought to be involved in cellulose degradation. Combining these results with known and partly re-evaluated metagenomic data strongly indicates that much like the human distal gut, the digestive system of herbivores harbours high numbers of deeply branched and as-yet uncultured members of the Bacteroidetes that depend on PUL-like systems for plant biomass degradation. PMID:22701672

  5. Renewable Energy Opportunity Assessment

    SciTech Connect

    Hancock, E.; Mas, C.

    1998-11-13

    Presently, the US EPA is constructing a new complex at Research Triangle Park, North Carolina to consolidate its research operations in the Raleigh-Durham area. The National Computer Center (NCC) is currently in the design process and is planned for construction as partof this complex. Implementation of the new technologies can be planned as part of the normal construction process, and full credit for elimination of the conventional technologies can be taken. Several renewable technologies are specified in the current plans for the buildings. The objective of this study is to identify measures that are likely to be both technically and economically feasible.

  6. ABUNDANCES OF GALACTIC ANTICENTER PLANETARY NEBULAE AND THE OXYGEN ABUNDANCE GRADIENT IN THE GALACTIC DISK

    SciTech Connect

    Henry, R. B. C.; Morrison, Michael A.; Kwitter, Karen B.; Jaskot, Anne E.; Balick, Bruce; Milingo, Jacquelynne B. E-mail: morrison@nhn.ou.ed E-mail: ajaskot@umich.ed E-mail: jmilingo@gettysburg.ed

    2010-11-20

    We have obtained spectrophotometric observations of 41 anticenter planetary nebulae (PNe) located in the disk of the Milky Way. Electron temperatures and densities, as well as chemical abundances for He, N, O, Ne, S, Cl, and Ar were determined. Incorporating these results into our existing database of PN abundances yielded a sample of 124 well-observed objects with homogeneously determined abundances extending from 0.9 to 21 kpc in galactocentric distance. We performed a detailed regression analysis which accounted for uncertainties in both oxygen abundances and radial distances in order to establish the metallicity gradient across the disk to be 12 + log(O/H) = (9.09 {+-} 0.05) - (0.058 {+-} 0.006) x R{sub g} , with R{sub g} in kpc. While we see some evidence that the gradient steepens at large galactocentric distances, more objects toward the anticenter need to be observed in order to confidently establish the true form of the metallicity gradient. We find no compelling evidence that the gradient differs between Peimbert Types I and II, nor is oxygen abundance related to the vertical distance from the galactic plane. Our gradient agrees well with analogous results for H II regions but is steeper than the one recently published by Stanghellini and Haywood over a similar range in galactocentric distance. A second analysis using PN distances from a different source implied a flatter gradient, and we suggest that we have reached a confusion limit which can only be resolved with greatly improved distance measurements and an understanding of the natural scatter in oxygen abundances.

  7. Recombinant renewable polyclonal antibodies

    PubMed Central

    Ferrara, Fortunato; D’Angelo, Sara; Gaiotto, Tiziano; Naranjo, Leslie; Tian, Hongzhao; Gräslund, Susanne; Dobrovetsky, Elena; Hraber, Peter; Lund-Johansen, Fridtjof; Saragozza, Silvia; Sblattero, Daniele; Kiss, Csaba; Bradbury, Andrew RM

    2015-01-01

    Only a small fraction of the antibodies in a traditional polyclonal antibody mixture recognize the target of interest, frequently resulting in undesirable polyreactivity. Here, we show that high-quality recombinant polyclonals, in which hundreds of different antibodies are all directed toward a target of interest, can be easily generated in vitro by combining phage and yeast display. We show that, unlike traditional polyclonals, which are limited resources, recombinant polyclonal antibodies can be amplified over one hundred million-fold without losing representation or functionality. Our protocol was tested on 9 different targets to demonstrate how the strategy allows the selective amplification of antibodies directed toward desirable target specific epitopes, such as those found in one protein but not a closely related one, and the elimination of antibodies recognizing common epitopes, without significant loss of diversity. These recombinant renewable polyclonal antibodies are usable in different assays, and can be generated in high throughput. This approach could potentially be used to develop highly specific recombinant renewable antibodies against all human gene products. PMID:25530082

  8. ALS renewal moves forward

    NASA Astrophysics Data System (ADS)

    Falcone, R. W.; Feinberg, B.; Hussain, Z.; Kirz, J.; Krebs, G. F.; Padmore, H. A.; Robin, D. S.; Robinson, A. L.

    2007-11-01

    As the result of an extensive long-term planning process involving all its stakeholders—management, staff, and users—the ALS has seen its future and is aggressively moving ahead to implement its vision for keeping the facility at the cutting edge for the next 2-3 decades. The evolving strategic plan now in place aims to renew the ALS so it can address a new generation of fundamental questions about size dependent and dimensional-confinement phenomena at the nanoscale; correlation and complexity in physical, biological, and environmental systems; and temporal evolution, assembly, dynamics and ultrafast phenomena. The renewal spans three areas: (1) increased staffing at beamlines to support the growing user community and safety professionals to keep an increasingly complex facility hazard free; (2) implementing advances in accelerator, insertion device, beamline, and detector technology that will make it possible for ALS users to address emerging grand scientific and technological challenges with incisive world-class tools; and (3) construction of a user support building and guest housing that will increase the safety and user friendliness of the ALS by providing users office, meeting, experiment staging, and laboratory space for their work and on-site accommodations at reasonable rates.

  9. Federal Renewable Energy Screening Assistant

    SciTech Connect

    Shelpuk, B; Walker, A

    1994-10-01

    The Federal Renewable Energy Screening Assistant is a software tool to be used by energy auditors to prioritize future studies of potentially cost-effective renewable energy applications at federal facilities. This paper describes the structure and function of the tool, gives an inventory of renewable energy technologies represented in the tool, and briefly describes the algorithms used to rank opportunities by the savings-to-investment ratio.

  10. Lake County renewable energy plan

    SciTech Connect

    Not Available

    1984-10-01

    This report documents the preparation of a renewable energy plan for Lake County, Oregon. It is the County's intention to adopt this plan as a supporting document to its Comprehensive Plan and implementing ordinances. The consideration of renewable energy in its land-use planning program is a statutory requirement for Lake County, and under the provisions of the Pacific Northwest Electric Power Planning and Conservation Act such renewable resource planning also fulfills regional energy objectives on a local level.

  11. Renewable energy development in China

    SciTech Connect

    Junfeng, Li

    1996-12-31

    This paper presents the resources availability, technologies development and their costs of renewable energies in China and introduces the programs of renewable energies technologies development and their adaptation for rural economic development in China. As the conclusion of this paper, renewable energies technologies are suitable for some rural areas, especially in the remote areas for both household energy and business activities energy demand. The paper looks at issues involving hydropower, wind energy, biomass combustion, geothermal energy, and solar energy.

  12. Solar and stellar photospheric abundances

    NASA Astrophysics Data System (ADS)

    Allende Prieto, Carlos

    2016-07-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  13. Factors Affecting Teaching the Concept of Renewable Energy in Technology Assisted Environments and Designing Processes in the Distance Education Model

    ERIC Educational Resources Information Center

    Yucel, A. Seda

    2007-01-01

    The energy policies of today focus mainly on sustainable energy systems and renewable energy resources. Chemistry is closely related to energy recycling, energy types, renewable energy, and nature-energy interaction; therefore, it is now an obligation to enrich chemistry classes with renewable energy concepts and related awareness. Before creating…

  14. Coronal abundances and their variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1995-01-01

    This contract supports the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution soft X-ray spectra from the Flat Crystal Spectrometer on the Solar Maximum Mission. The goals of the study are a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This report is a summation of the data analysis and reporting activities which occurred during the period of 15 April 1994 to 15 April 1995.

  15. The solar abundance of beryllium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    The solar abundance of beryllium is deduced from high-resolution Kitt Peak observations of the 3130.43- and 3131.08-A lines of Be II interpreted by the method of spectrum synthesis. The results are in good agreement with those previously obtained by Grevesse (1968) and by Hauge and Engvold (1968) and indicate that in the photospheric layers, beryllium is depleted below the chondritic value by a factor of about two. It is found that the beryllium abundance is equal to logN(Be)/N(H) + 12 = 1.08 plus or minus 0.05.

  16. Chemical Abundances of Symbiotic Giants

    NASA Astrophysics Data System (ADS)

    Gałan, C.; Mikołajewska, J.; Hinkle, K. H.; Joyce, R. R.

    2015-12-01

    High resolution (R ˜ 50000), near-IR spectra were used to measure photospheric abundances of CNO and elements around the iron peak for 24 symbiotic giants. Spectrum synthesis was employed using local thermal equilibrium and hydrostatic model atmospheres. The metallicities are distributed in a wide range with maximum around [Fe/H] ˜-0.4 - - 0.3 dex. Enrichment in 14N indicates that all the sample giants have experienced the first dredge-up. The relative abundance of [Ti/Fe] is generally large in red symbiotic systems.

  17. Coronal Abundances and Their Variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1996-01-01

    This contract supported the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution soft X-ray spectra from the Flat Crystal Spectrometer on NASA's Solar Maximum Mission. The goals of the study were a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This is the Final Report, summarizing the data analysis and reporting activities which occurred during the period of performance, June 1993 - December 1996.

  18. SOLAR MODELS WITH REVISED ABUNDANCE

    SciTech Connect

    Bi, S. L.; Li, T. D.; Yang, W. M.; Li, L. H.

    2011-04-20

    We present new solar models in which we use the latest low abundances and further include the effects of rotation, magnetic fields, and extra-mixing processes. We assume that the extra-element mixing can be treated as a diffusion process, with the diffusion coefficient depending mainly on the solar internal configuration of rotation and magnetic fields. We find that such models can well reproduce the observed solar rotation profile in the radiative region. Furthermore, the proposed models can match the seismic constraints better than the standard solar models, also when these include the latest abundances, but neglect the effects of rotation and magnetic fields.

  19. Renewable Energy for the Paranal Observatory

    NASA Astrophysics Data System (ADS)

    Weilenmann, U.

    2012-06-01

    The operation of observatories at remote sites presents significant demands for electrical energy. The use of renewable energy may become the solution to cope with the ever-rising prices for electrical energy produced from fossil fuels. There is not only a purely commercial aspect, but also the carbon footprint of observatory activities has to be considered. As a first step on the way to a "greener" Paranal Observatory, we propose the installation of a solar cooling system for the cooling of the telescope enclosures, using the abundant insolation that is freely available in the north of Chile. Further into the future, feasible options for photovoltaic and wind energy could supply the needs of the Paranal Observatory in a sustainable manner.

  20. EDITORIAL: Renewing energy technology Renewing energy technology

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2011-06-01

    Renewable energy is now a mainstream concern among businesses and governments across the world, and could be considered a characteristic preoccupation of our time. It is interesting to note that many of the energy technologies currently being developed date back to very different eras, and even predate the industrial revolution. The fuel cell was first invented as long ago as 1838 by the Swiss--German chemist Christian Friedrich Schönbein [1], and the idea of harnessing solar power dates back to ancient Greece [2]. The enduring fascination with new means of harnessing energy is no doubt linked to man's innate delight in expending it, whether it be to satisfy the drive of curiosity, or from a hunger for entertainment, or to power automated labour-saving devices. But this must be galvanized by the sustained ability to improve device performance, unearthing original science, and asking new questions, for example regarding the durability of photovoltaic devices [3]. As in so many fields, advances in hydrogen storage technology for fuel cells have benefited significantly from nanotechnology. The idea is that the kinetics of hydrogen uptake and release may be reduced by decreasing the particle size. An understanding of how effective this may be has been hampered by limited knowledge of the way the thermodynamics are affected by atom or molecule cluster size. Detailed calculations of individual atoms in clusters are limited by computational resources as to the number of atoms that can studied, and other innovative approaches that deal with force fields derived by extrapolating the difference between the properties of clusters and bulk matter require labour-intensive modifications when extending such studies to new materials. In [4], researchers in the US use an alternative approach, considering the nanoparticle as having the same crystal structure as the bulk but relaxing the few layers of atoms near the surface. The favourable features of nanostructures for catalysis

  1. Rewards of renewables

    NASA Astrophysics Data System (ADS)

    McNamee, Gregory

    2008-09-01

    In 1987 an American-style fridge freezer would use about 950 kWh of electricity and cost about 150 (£80) a year to run. Two decades on, a comparable appliance uses half the electricity and costs less than half as much to run. In 1975 there were about 3780 000 cars on the streets of Los Angeles, whereas today there are more than 5200 000 - yet air-pollution levels have fallen by half and an increasing number of those vehicles are hybrids or rely on renewable fuels like bio-diesel. Last year, half a million homes in Southern California were receiving direct solar power, either from solar electricity plants or from rooftop photovoltaic panels.

  2. Renewable jet fuel.

    PubMed

    Kallio, Pauli; Pásztor, András; Akhtar, M Kalim; Jones, Patrik R

    2014-04-01

    Novel strategies for sustainable replacement of finite fossil fuels are intensely pursued in fundamental research, applied science and industry. In the case of jet fuels used in gas-turbine engine aircrafts, the production and use of synthetic bio-derived kerosenes are advancing rapidly. Microbial biotechnology could potentially also be used to complement the renewable production of jet fuel, as demonstrated by the production of bioethanol and biodiesel for piston engine vehicles. Engineered microbial biosynthesis of medium chain length alkanes, which constitute the major fraction of petroleum-based jet fuels, was recently demonstrated. Although efficiencies currently are far from that needed for commercial application, this discovery has spurred research towards future production platforms using both fermentative and direct photobiological routes. PMID:24679258

  3. Renewable Energy Certificate Program

    SciTech Connect

    Gwendolyn S. Andersen

    2012-07-17

    This project was primarily to develop and implement a curriculum which will train undergraduate and graduate students at the University seeking a degree as well as training for enrollees in a special certification program to prepare individuals to be employed in a broad range of occupations in the field of renewable energy and energy conservation. Curriculum development was by teams of Saint Francis University Faculty in the Business Administration and Science Departments and industry experts. Students seeking undergraduate and graduate degrees are able to enroll in courses offered within these departments which will combine theory and hands-on training in the various elements of wind power development. For example, the business department curriculum areas include economic modeling, finance, contracting, etc. The science areas include meteorology, energy conversion and projection, species identification, habitat protection, field data collection and analysis, etc.

  4. Renewal of radiological equipment.

    PubMed

    2014-10-01

    In this century, medical imaging is at the heart of medical practice. Besides providing fast and accurate diagnosis, advances in radiology equipment offer new and previously non-existing options for treatment guidance with quite low morbidity, resulting in the improvement of health outcomes and quality of life for the patients. Although rapid technological development created new medical imaging modalities and methods, the same progress speed resulted in accelerated technical and functional obsolescence of the same medical imaging equipment, consequently creating a need for renewal. Older equipment has a high risk of failures and breakdowns, which might cause delays in diagnosis and treatment of the patient, and safety problems both for the patient and the medical staff. The European Society of Radiology is promoting the use of up-to-date equipment, especially in the context of the EuroSafe Imaging Campaign, as the use of up-to-date equipment will improve quality and safety in medical imaging. Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or renewal. This plan should look forward a minimum of 5 years, with annual updates. Teaching points • Radiological equipment has a definite life cycle span, resulting in unavoidable breakdown and decrease or loss of image quality which renders equipment useless after a certain time period.• Equipment older than 10 years is no longer state-of-the art equipment and replacement is essential. Operating costs of older equipment will be high when compared with new equipment, and sometimes maintenance will be impossible if no spare parts are available.• Older equipment has a high risk of failure and breakdown, causing delays in diagnosis and treatment of the patient and safety problems both for the patient and the medical staff.• Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or replacement. This plan should look forward a

  5. THE SOLAR FLARE IRON ABUNDANCE

    SciTech Connect

    Phillips, K. J. H.; Dennis, B. R. E-mail: Brian.R.Dennis@nasa.gov

    2012-03-20

    The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in RHESSI X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an isothermal assumption and improved data analysis methods over previous work. Two spectral fitting models give comparable results, viz., an iron abundance that is lower than previous coronal values but higher than photospheric values. In the preferred method, the estimated Fe abundance is A(Fe) = 7.91 {+-} 0.10 (on a logarithmic scale, with A(H) = 12) or 2.6 {+-} 0.6 times the photospheric Fe abundance. Our estimate is based on a detailed analysis of 1898 spectra taken during 20 flares. No variation from flare to flare is indicated. This argues for a fractionation mechanism similar to quiet-Sun plasma. The new value of A(Fe) has important implications for radiation loss curves, which are estimated.

  6. Cationically polymerizable monomers derived from renewable sources. Annual performance report

    SciTech Connect

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year`s research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  7. Solid biopolymer electrolytes came from renewable biopolymer

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Zhang, Xingxiang; Qiao, Zhijun; Liu, Haihui

    2009-07-01

    Solid polymer electrolytes (SPEs) have attracted many attentions as solid state ionic conductors, because of their advantages such as high energy density, electrochemical stability, and easy processing. SPEs obtained from starch have attracted many attentions in recent years because of its abundant, renewable, low price, biodegradable and biocompatible. In addition, the efficient utilization of biodegradable polymers came from renewable sources is becoming increasingly important due to diminishing resources of fossil fuels as well as white pollution caused by undegradable plastics based on petroleum. So N, N-dimethylacetamide (DMAc) with certain concentration ranges of lithium chloride (LiCl) is used as plasticizers of cornstarch. Li+ can complexes with the carbonyl atoms of DMAc molecules to produce a macro-cation and leave the Cl- free to hydrogen bond with the hydroxyl or carbonyl of starch. This competitive hydrogen bond formation serves to disrupt the intra- and intermolecular hydrogen bonding existed in starch. Therefore, melt extrusion process conditions are used to prepare conductive thermoplastic starch (TPS). The improvements of LiCl concentration increase the water absorption and conductance of TPS. The conductance of TPS containing 0.14 mol LiCl achieve to 10-0.5 S cm-1 with 18 wt% water content.

  8. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    SciTech Connect

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  9. Renewable Energy Alternatives in Maryland.

    ERIC Educational Resources Information Center

    Welsh, Greg E.; McClellan, Deborah A. S.

    This handbook discusses the renewable energy resources suitable for use in Maryland. It follows a question and answer format with sections about the following alternative renewable energy sources; solar, wind, wood, water, bio-gas/methane, and geothermal. Each section includes a list of recommended readings, appropriate agencies or organizations,…

  10. The Paradox in Institutional Renewal.

    ERIC Educational Resources Information Center

    Cameron, Kim

    The renewal of institutions and maintenance of excellence in the uncertain future are discussed, based on research with 335 four-year universities and colleges. In examining the function of paradox in adaptation and renewal, it was found that individuals who can simultaneously focus on opposites, or paradoxes, are tolerant and flexible.…

  11. Actinide abundances in ordinary chondrites

    USGS Publications Warehouse

    Hagee, B.; Bernatowicz, T.J.; Podosek, F.A.; Johnson, M.L.; Burnett, D.S.; Tatsumoto, M.

    1990-01-01

    Measurements of 244Pu fission Xe, U, Th, and light REE (LREE) abundances, along with modal petrographic determinations of phosphate abundances, were carried out on equilibrated ordinary chondrites in order to define better the solar system Pu abundance and to determine the degree of variation of actinide and LREE abundances. Our data permit comparison of the directly measured Pu/ U ratio with that determined indirectly as (Pu/Nd) ?? (Nd/U) assuming that Pu behaves chemically as a LREE. Except for Guaren??a, and perhaps H chondrites in general, Pu concentrations are similar to that determined previously for St. Se??verin, although less precise because of higher trapped Xe contents. Trapped 130Xe 136Xe ratios appear to vary from meteorite to meteorite, but, relative to AVCC, all are similar in the sense of having less of the interstellar heavy Xe found in carbonaceous chondrite acid residues. The Pu/U and Pu/Nd ratios are consistent with previous data for St. Se??verin, but both tend to be slightly higher than those inferred from previous data on Angra dos Reis. Although significant variations exist, the distribution of our Th/U ratios, along with other precise isotope dilution data for ordinary chondrites, is rather symmetric about the CI chondrite value; however, actinide/(LREE) ratios are systematically lower than the CI value. Variations in actinide or LREE absolute and relative abundances are interpreted as reflecting differences in the proportions and/or compositions of more primitive components (chondrules and CAI materials?) incorporated into different regions of the ordinary chondrite parent bodies. The observed variations of Th/U, Nd/U, or Ce/U suggest that measurements of Pu/U on any single equilibrated ordinary chondrite specimen, such as St. Se??verin, should statistically be within ??20-30% of the average solar system value, although it is also clear that anomalous samples exist. ?? 1990.

  12. Geographical Range and Local Abundance of Tree Species in China

    PubMed Central

    Ren, Haibao; Condit, Richard; Chen, Bin; Mi, Xiangcheng; Cao, Min; Ye, Wanhui; Hao, Zhanqing; Ma, Keping

    2013-01-01

    Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1) whether locally abundant species tend to be geographically widespread; 2) whether species are more abundant towards their range-centers; and 3) how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20–25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km2, and >90% of 651 species had ranges >105 km2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species’ abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges. PMID:24130772

  13. Abundance Inequality in Freshwater Communities Has an Ecological Origin.

    PubMed

    Passy, Sophia I

    2016-04-01

    The hollow-shaped species abundance distribution (SAD) and its allied rank abundance distribution (RAD)-showing that abundance is unevenly distributed among species-are some of the most studied patterns in ecology. To explain the nature of abundance inequality, I developed a novel framework identifying environmental favorability, which controls the balance between reproduction and immigration, as the ultimate source and species stress tolerance as a proximate factor. Thus, under harsh conditions, only a few tolerant species can reproduce, while some sensitive species can be present in low numbers due to chance immigration. This would lead to high abundance inequality between the two groups of species. Under benign conditions, both groups can reproduce and give rise to higher abundance equality. To test these ideas, I examined the variability in the parameters of a Poisson lognormal fit of the SAD and a square root fit of the RAD in diatom and fish communities across US streams. Indeed, as environmental favorability increased, more sensitive forms were able to establish large populations, diminishing the abundance disparity between locally common and rare species. Finally, it was demonstrated that in diatoms, the RAD belonged to the same family of relationships as those of population density with body size and regional distribution. PMID:27028078

  14. DSM renewable opportunities in Boston

    SciTech Connect

    Tennis, M.W.; Nogee, A.J.; Coakley, S.; Schoengold, D.

    1995-11-01

    The Union of Concerned Scientists (UCS), in conjunction with MSB Energy Associates, conducted a study for the Boston Edison Demand-Side Management (DSM) Settlement Board on the potential for DSM renewables in the Boston area. DSM renewables are resources that can be used in a distributed utility approach to avoid transmission and distribution (T and D) costs, as well as costs associated with operating and building power plants. The results show that avoided costs in areas with deferrable T and D investments can be nearly twice as high as system-wide average avoided costs. As a result, renewable technologies that might not be considered cost effective as DSM under system-wide average criteria, can produce large shavings for the utility and its customers. Adopting a deliberate program designed to provide sustained orderly development of these renewables is essential in order for renewable technologies to achieve the maximum level of cost-effectiveness and net savings.

  15. Prickly business: abundance of sea urchins on breakwaters and coral reefs in Dubai.

    PubMed

    Bauman, Andrew G; Dunshea, Glenn; Feary, David A; Hoey, Andrew S

    2016-04-30

    Echinometra mathaei is a common echinoid on tropical reefs and where abundant plays an important role in the control of algal communities. Despite high prevalence of E. mathaei on southern Persian/Arabian Gulf reefs, their abundance and distribution is poorly known. Spatial and temporal patterns in population abundance were examined at 12 sites between breakwater and natural reef habitats in Dubai (UAE) every 3 months from 2008 to 2010. Within the breakwater habitat, densities were greatest at shallow wave-exposed sites, and reduced with both decreasing wave-exposure and increasing depth. Interestingly, E. mathaei were significantly more abundant on exposed breakwaters than natural reef sites, presumably due to differences in habitat structure and benthic cover. Population abundances differed seasonally, with peak abundances during summer (July-September) and lower abundances in winter (December-February). Seasonal fluctuations are likely the result of peak annual recruitment pulses coupled with increased fish predation from summer to winter. PMID:26563547

  16. Space Solar Power and Other Renewable Energy Sources: Understanding the Market

    NASA Astrophysics Data System (ADS)

    MacAuley, Molly K.

    2002-01-01

    fossil fuels. In addition, a ground-based electricity generation system is now increasingly realized as also vulnerable to disruption. What advantages does space solar power (SSP) offer over other renewable energy sources (wind, terrestrial photovoltaics, biopower, and geothermal) in addressing these concerns? What are disadvantages? This paper discusses the economics of renewable energy in the United States' market in two geographic regions (the west coast and the north central regions) where renewable energy resources are abundant and relatively low cost (thus, aggressively competitive with SSP), but where the security and reliability advantages of SSP may indeed outweigh any generation cost advantage of the terrestrial technologies.

  17. Dermal Contributions to Human Interfollicular Epidermal Architecture and Self-Renewal

    PubMed Central

    Lawlor, Kynan T.; Kaur, Pritinder

    2015-01-01

    The human interfollicular epidermis is renewed throughout life by populations of proliferating basal keratinocytes. Though interfollicular keratinocyte stem cells have been identified, it is not known how self-renewal in this compartment is spatially organized. At the epidermal-dermal junction, keratinocytes sit atop a heterogeneous mix of dermal cells that may regulate keratinocyte self-renewal by influencing local tissue architecture and signalling microenvironments. Focusing on the rete ridges and complementary dermal papillae in human skin, we review the identity and organisation of abundant dermal cells types and present evidence for interactions between the dermal microenvironment and the interfollicular keratinocytes. PMID:26602926

  18. Preliminary investigation of biogenic gas production in Indonesian low rank coals and implications for a renewable energy source

    NASA Astrophysics Data System (ADS)

    Susilawati, Rita; Papendick, Sam L.; Gilcrease, Patrick C.; Esterle, Joan S.; Golding, Suzanne D.; Mares, Tennille E.

    2013-11-01

    Indonesia has abundant coal resources at depths suitable to contain substantial volumes of naturally occurring methane, which are currently being explored. Most Indonesian coals are thermally immature, but are composed of hydrogen-rich organic components that are presumed to make them excellent substrates for biogenic methane production. Gas isotope results from pilot wells in South Sumatra, reported in this study, are interpreted to indicate biogenic origins for the methane. Corresponding formation water samples were collected and incubated, and show the presence of indigenous microbial communities capable of producing methane from Indonesian and Australian coal. Although these results are only preliminary, they are promising and support the possibility of Indonesia developing bio renewable energy from coal seams.

  19. The integration of renewable energy sources into electric power transmission systems

    SciTech Connect

    Barnes, P.R.; Dykas, W.P.; Kirby, B.J.; Purucker, S.L.; Lawler, J.S.

    1995-07-01

    Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads without transmission upgrades beyond the construction of a substation to connect to the grid. Except in the Southwest, significant investment to strengthen transmission systems will be required to support the development of high-capacity renewable sources of 1000 MW or greater in areas remote from major load centers. Cost estimates for new transmission facilities to integrate and dispatch some of these high-capacity renewable sources ranged from several million dollars to approximately one billion dollars, with the latter figure an increase in total investment of 35%, assuming that the renewable source is the only user of the transmission facility.

  20. Multiple peaks of species abundance distributions induced by sparse interactions.

    PubMed

    Obuchi, Tomoyuki; Kabashima, Yoshiyuki; Tokita, Kei

    2016-08-01

    We investigate the replicator dynamics with "sparse" symmetric interactions which represent specialist-specialist interactions in ecological communities. By considering a large self-interaction u, we conduct a perturbative expansion which manifests that the nature of the interactions has a direct impact on the species abundance distribution. The central results are all species coexistence in a realistic range of the model parameters and that a certain discrete nature of the interactions induces multiple peaks in the species abundance distribution, providing the possibility of theoretically explaining multiple peaks observed in various field studies. To get more quantitative information, we also construct a non-perturbative theory which becomes exact on tree-like networks if all the species coexist, providing exact critical values of u below which extinct species emerge. Numerical simulations in various different situations are conducted and they clarify the robustness of the presented mechanism of all species coexistence and multiple peaks in the species abundance distributions. PMID:27627322

  1. Battery storage for supplementing renewable energy systems

    SciTech Connect

    None, None

    2009-01-18

    The battery storage for renewable energy systems section of the Renewable Energy Technology Characterizations describes structures and models to support the technical and economic status of emerging renewable energy options for electricity supply.

  2. Analysis of a 10% Renewable Portfolio Standard

    EIA Publications

    2003-01-01

    On May 8, 2003, Senator Jeff Bingaman, the Ranking Minority Member of the Senate Committee on Energy and Natural Resources, requested an analysis of a nationwide Renewable Portfolio Standard (RPS) program proposed to be amended to energy legislation currently pending before the U.S. Senate. With his request Sen. Bingaman provided specific information on the program to be analyzed. This analysis was prepared in response to his request and projects the impact of the proposed program on energy supply, demand, prices, and emissions. The analysis is based on the Annual Energy Outlook 2003 (AEO2003) projections of energy supply, demand, and prices through 2025, as updated in May 2003.

  3. Renewable Energy Opportunities Saginaw Chippewa Indian Tribe

    SciTech Connect

    Saginaw Chippewa Indian Tribe Planning Department; Smiley, Steve; Bennett, Keith, DOE Project Officer

    2008-10-22

    The Saginaw Chippewa Indian Tribe has a vision to become self-sufficient in its energy needs and to maintain its culture and protect Mother Earth with respect and honor for the next seven generations. To achieve this vision, green energy sources such as solar, wind and biomass energy are the best energy paths to travel. In this feasibility study the Tribe has analyzed and provided data on the nature of the renewable resources available to the Tribe and the costs of implementing these technologies.

  4. Abundance anomalies in tidal disruption events

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2016-05-01

    The ˜10 per cent of tidal disruption events (TDEs) due to stars more massive than M* ≳ M⊙ should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ˜25 per cent on average because it becomes inaccessible once it is sequestered in the high-density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main-sequence star can be enhanced in helium by factors of 2-3 for debris at a common orbital period. These helium abundance variations may be a contributor to the observed diversity of hydrogen and helium line strengths in TDEs. A still more striking anomaly is the rapid enhancement of nitrogen and the depletion of carbon due to the CNO cycle - stars with M* ≳ M⊙ quickly show an increase in their average N/C ratio by factors of 3-10. Because low-mass stars evolve slowly and high-mass stars are rare, TDEs showing high N/C will almost all be due to ˜1-2 M⊙ stars disrupted on the main sequence. Like helium, portions of the debris will show still larger changes in C and N, and the anomalies decline as the star leaves the main sequence. The enhanced [N/C] abundance ratio of these TDEs provides the first natural explanation for the rare, nitrogen-rich quasars and may also explain the strong nitrogen emission seen in ultraviolet spectra of ASASSN-14li.

  5. Building a sustainable market for renewables

    SciTech Connect

    Rader, N.

    1996-12-31

    Opinions regarding marketing approaches for electricity generation from renewable resources are presented in the paper. The Renewables Portfolio Standard of the California Public Utilities Commission is described. This system is based on renewable energy credits. Other marketing approaches, including surcharges, auctioned renewables credit, green pricing, and green marketing are also assessed. It is concluded that the Renewables Portfolio Standard creates a stable economic environment for the renewable energy industries.

  6. The solar abundance of thulium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    Consideration of one relatively unblended line of the solar spectrum, namely, the 3131.258-A line of Tm II, which yields a thulium abundance of 0.80 plus or minus 0.10 with the Corliss and Bozman (1962) f-value. The uncertainty of this figure is discussed in conjunction with the contradictory findings of some other investigators. The need for further detailed study of the lanthanides by the method of spectrum synthesis is pointed out.

  7. Current and relic carbon using natural abundance carbon-13

    SciTech Connect

    layse,MF; Clapp,CE; Allmaras,RR; Linden,D.R; Molina, JAE.; Copeland,SM; Dowdy,RH

    2002-05-01

    The role of agricultural practices on soil carbon (C) dynamics is critical to improved soil management. The main objective was to examine the C interactions resulting from crop changes under different tillage and residue treatments.

  8. Jobs and Renewable Energy Project

    SciTech Connect

    Sterzinger, George

    2006-12-19

    Early in 2002, REPP developed the Jobs Calculator, a tool that calculates the number of direct jobs resulting from renewable energy development under RPS (Renewable Portfolio Standard) legislation or other programs to accelerate renewable energy development. The calculator is based on a survey of current industry practices to assess the number and type of jobs that will result from the enactment of a RPS. This project built upon and significantly enhanced the initial Jobs Calculator model by (1) expanding the survey to include other renewable technologies (the original model was limited to wind, solar PV and biomass co-firing technologies); (2) more precisely calculating the economic development benefits related to renewable energy development; (3) completing and regularly updating the survey of the commercially active renewable energy firms to determine kinds and number of jobs directly created; and (4) developing and implementing a technology to locate where the economic activity related to each type of renewable technology is likely to occur. REPP worked directly with groups in the State of Nevada to interpret the results and develop policies to capture as much of the economic benefits as possible for the state through technology selection, training program options, and outreach to manufacturing groups.

  9. Developing Government Renewable Energy Projects

    SciTech Connect

    Kurt S. Myers; Thomas L. Baldwin; Jason W. Bush; Jake P. Gentle

    2012-07-01

    The US Army Corps of Engineers has retained Idaho National Laboratory (INL) to conduct a study of past INL experiences and complete a report that identifies the processes that are needed for the development of renewable energy projects on government properties. The INL has always maintained expertise in power systems and applied engineering and INL’s renewable energy experiences date back to the 1980’s when our engineers began performing US Air Force wind energy feasibility studies and development projects. Over the last 20+ years of working with Department of Defense and other government agencies to study, design, and build government renewable projects, INL has experienced the do’s and don’ts for being successful with a project. These compiled guidelines for government renewable energy projects could include wind, hydro, geothermal, solar, biomass, or a variety of hybrid systems; however, for the purpose of narrowing the focus of this report, wind projects are the main topic discussed throughout this report. It is our thought that a lot of what is discussed could be applied, possibly with some modifications, to other areas of renewable energy. It is also important to note that individual projects (regardless the type) vary to some degree depending on location, size, and need but in general these concepts and directions can be carried over to the majority of government renewable energy projects. This report focuses on the initial development that needs to occur for any project to be a successful government renewable energy project.

  10. Chlorine Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Bogard, D.D.; Garrison, D.H.; Park, J.

    2009-01-01

    Chlorine measurements made in martian surface rocks by robotic spacecraft typically give Chlorine (Cl) abundances of approximately 0.1-0.8%. In contrast, Cl abundances in martian meteorites appear lower, although data is limited, and martian nakhlites were also subjected to Cl contamination by Mars surface brines. Chlorine abundances reported by one lab for whole rock (WR) samples of Shergotty, ALH77005, and EET79001 range 108-14 ppm, whereas Cl in nakhlites range 73-1900 ppm. Measurements of Cl in various martian weathering phases of nakhlites varied 0.04-4.7% and reveal significant concentration of Cl by martian brines Martian meteorites contain much lower Chlorine than those measured in martian surface rocks and give further confirmation that Cl in these surface rocks was introduced by brines and weathering. It has been argued that Cl is twice as effective as water in lowering the melting point and promoting melting at shallower martian depths, and that significant Cl in the shergottite source region would negate any need for significant water. However, this conclusion was based on experiments that utilized Cl concentrations more analogous to martian surface rocks than to shergottite meteorites, and may not be applicable to shergottites.

  11. Surface abundances of OC supergiants

    NASA Astrophysics Data System (ADS)

    Martins, F.; Foschino, S.; Bouret, J.-C.; Barbá, R.; Howarth, I.

    2016-04-01

    Context. Some O and B stars show unusually strong or weak lines of carbon and/or nitrogen. These objects are classified as OBN or OBC stars. It has recently been shown that nitrogen enrichment and carbon depletion are the most likely explanations for the existence of the ON class. Aims: We investigate OC stars (all being supergiants) to check that surface abundances are responsible for the observed anomalous line strengths. Methods: We perform a spectroscopic analysis of three OC supergiants using atmosphere models. A fourth star was previously studied by us. Our sample thus comprises all OC stars known to date in the Galaxy. We determine the stellar parameters and He, C, N, and O surface abundances. Results: We show that all stars have effective temperatures and surface gravities fully consistent with morphologically normal O supergiants. However, OC stars show little, if any, nitrogen enrichment and carbon surface abundances consistent with the initial composition. OC supergiants are thus barely chemically evolved, unlike morphologically normal O supergiants. Based on observations obtained at the ESO/La Silla Observatory under programs 081.D-2008, 083.D-0589, 089.D-0975.

  12. Robust Abundance Estimation in Animal Surveys with Imperfect Detection

    EPA Science Inventory

    Surveys of animal abundance are central to the conservation and management of living natural resources. However, detection uncertainty complicates the sampling process of many species. One sampling method employed to deal with this problem is depletion (or removal) surveys in whi...

  13. Marine Renewable Energy Center

    SciTech Connect

    Vigeant, Paul; Miller, John; Howes, Brian; McGowan, Jon G.; Baldwin, Kenneth; Grilli, Annette; Terray, Eugene

    2013-10-08

    Project Goals: The funding provided by this contract supported the following activities: A) Test Site Development; B) Seed Grant Funded Technology Development; C) Stakeholder Activities The first year of funding was dedicated to the formation of the NE MREC University Consortium which was comprised of University of Massachusetts Dartmouth (UMD) and Amherst (UMA), Massachusetts Institute of Technology (MIT), Woods Hole Oceanographic Institution (WHOI), University of New Hampshire (UNH), and the University of Rhode Island (URI). The consortium worked together to encourage research and promote benefits of obtaining energy from ocean wind, waves, tides and currents. In addition, NE MREC’s goal was to fund projects aimed at potential test sites with the first year funding going to studies of the potential for tidal device testing in Muskeget Channel, at the General Sullivan Bridge in New Hampshire, and for wave device testing at the proposed National Offshore Renewable Energy Innovation Zone (NOREIZ) located off the Massachusetts coast. The project spanned 4.5 years and addressed three specific tasks that are interrelated but also served as independent investigations.

  14. Renewable energy potential in Colombia

    NASA Astrophysics Data System (ADS)

    Correa Guzman, Jose Luis

    2008-12-01

    Renewable energy flows are very large in comparison with humankind's use of energy. In principle, all our energy needs, both now and into the future, can be met by energy from renewable sources. After many years trying to develop the alternative energy potential of Colombia, a major effort is principally being made since 2000 to explore and assess the renewable resources of the entire country. Until 2000, the availability of conventional energy sources in Colombia prevented renewable energy exploration from reaching a higher level. However, the extreme energy crisis of 1992 - 1993 alerted the authorities and the community to the necessity for exploring alternative energy sources. This energy study is a general approach to the current and future renewable energy scenario of Colombia. It was prepared in response to the increased interest around the world and in particular in Colombia to develop its non-fossil energy prospective. It, therefore, represents a working document giving an initial impression of the possible scale of the main renewables sources as a response to the concern about energy security and fossil fuel dependence problems. The assumptions made and calculations reported may therefore be subject to revision as more information becomes available. The aim of this dissertation is not only to improve the public understanding and discussion of renewable energy matters in Colombia but also to stimulate the development and application of renewable energy, wherever they have prospects of economic viability and environmental acceptability. To achieve such goal this paper reviews several renewable technologies, their availability, contribution and feasibility in Colombia.

  15. 2012 Renewable Energy Data Book

    DOE Data Explorer

    The 2012 Renewable Energy Data Book is 128 pages of data in tables, figures and charts, and text. It provides a look at resources and usage for wind, solar, geothermal, hydro, hydrogen, and biopower. Developed at the National Renewable Energy Laboratory (NREL) for DOE's Office of Energy Efficiency and Renewable Energy (EERE), it was produced by Rachel Gelman, edited by Mike Meshek, and designed by Stacy Buchanan and Erica Augustine and released in October, 2013. Report number for this data book is DOE/GO-102013-4291.

  16. The Abundance of Interstellar Fluorine

    NASA Technical Reports Server (NTRS)

    Lauroesch, James T.

    2005-01-01

    The primary objective of this program was to obtain FUSE observations of the interstellar absorption lines of F I at 951 and 954 Angstroms to derive the abundance of fluorine toward the star HD 164816. The nucleosynthetic source(s) of fluorine are still a matter of debate - the present day abundance of fluorine can potentially constrain models for pulsationally driven dredge-up in asymptotic giant branch stars. An accurate measure for the depletion behavior of fluorine will determine whether it may be detectable in QSO absorption line systems - an unambiguous detection of fluorine at suitably high redshifts would provide the best evidence to date for the neutrino process in massive stars. Furthermore, due to its extreme reactivity, measurement of the gas-phase interstellar fluorine abundance is important for models of grain chemistry. Despite the importance of measuring the interstellar fluorine abundance, at the time of our proposal only one previous detection has been made due to the low relative abundance of fluorine, the lack of lines outside the far-UV, and the blending of the available F I transitions with lines of Hz. The star HD 164816 is associated with the Lagoon nebula (M8), and at a distance of approximately 1.5 kpc probes both distant and local gas. Beginning April 8th, 2004 FUSE FP-Split observations of the star HD 164816 were obtained for this program. This data became available in the FUSE data archive May 21, 2004, and these observations were then downloaded and we began our analysis. Our analysis procedure has involved (1) fitting stellar models to the FUSE spectra, (2) using the multiple lines of Hz and N I at other wavelengths in the FUSE bandpass to derive column densities for the lines of H2 and N I which are blended with the F I features at 951 and 954 angstroms (3) the measurement of the column densities of F I and the species O I and C1 I which are important species for the dis-entangling of dust and nucleosynthetic effects. As discussed in

  17. Nanostructured Materials for Renewable Energy

    SciTech Connect

    2009-11-01

    This factsheet describes a research project whose overall objective is to advance the fundamental understanding of novel photoelectronic organic device structures integrated with inorganic nanostructures, while also expanding the general field of nanomaterials for renewable energy devices and systems.

  18. Renewable Fuels Module - NEMS Documentation

    EIA Publications

    2014-01-01

    This report documents the objectives, analytical approach, and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it relates to the production of the Annual Energy Outlook forecasts.

  19. Renewable energy opportunities in China

    NASA Astrophysics Data System (ADS)

    Wallace, William L.; Simon Tsuo, Y.

    1996-01-01

    Rapid growth in economic development coupled with the absence of an electric grid in large areas of rural China have created a need for new energy sources both in urban centers and the rural countryside. Electric capacity expansion plans call for increased use of coal-fired steam turbines for electricity production that will contribute to increased concerns over environmental pollution. China is rich in renewable energy resources, strategically located in areas of greatest need and economic viability. China is also already one of the world's largest users of renewables, especially hydro, wind, biomass, and solar thermal, and has significant experience with photovoltaics, geothermal and other technologies. The use of renewable energy is being encouraged in expanded programs at the central and provincial government levels, with growing private sector involvement. These conditions create opportunities for U.S. business participation in renewable energy markets in China.

  20. FEMP Renewable Energy Program Overview

    SciTech Connect

    2010-07-14

    Fact sheet describing how the U.S. Department of Energy's (DOE) Federal Energy Management Program (FEMP) provides Federal agencies with information, guidance, and assistance in using renewable energy.

  1. Teacher Contract Non-Renewal: Southeast and Midwest Principals

    ERIC Educational Resources Information Center

    Nixon, Andy; Packard, Abbot L; Dam, Margaret

    2011-01-01

    This quantitative study investigated reasons that school principals recommend non-renewal of probationary teachers' contracts. Principals in the Southeast and Midwest completed an emailed survey. The ordinal nature of the data gathered dictated that comparisons be made between groups using the Mann Whitney U. The study investigated the barriers…

  2. Renewable Electricity Policy in Germany, 1974 to 2005

    ERIC Educational Resources Information Center

    Lauber, Volkmar; Mez, Lutz

    2006-01-01

    Of the large industrial countries, Germany is clearly leading with regard to new renewable energy sources, occupying first rank in terms of installed capacity for wind energy and second for photovoltaics. This is not because of an exceptional natural resource base but because of public policy in this area, despite the fact that this policy was…

  3. A Data Envelopment Analysis Model for Renewable Energy Technology Selection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Public and media interest in alternative energy sources, such as renewable fuels, has rapidly increased in recent years due to higher prices for oil and natural gas. However, the current body of research providing comparative decision making models that either rank these alternative energy sources a...

  4. Strategic Planning: Renewal and Redesign during Turbulent Times

    ERIC Educational Resources Information Center

    Cherrey, Cynthia; Clark, Evette Castillo

    2010-01-01

    In August 2005, Hurricane Katrina, the worst natural disaster in the history of the United States, forced the fall semester closure of Tulane University in New Orleans, Louisiana. In the aftermath of this unprecedented storm, the Tulane leadership set forth a plan for renewal to secure the survival, recovery, and sustainability of the institution,…

  5. Urban Warming Drives Insect Pest Abundance on Street Trees

    PubMed Central

    Meineke, Emily K.; Dunn, Robert R.; Sexton, Joseph O.; Frank, Steven D.

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer. PMID:23544087

  6. Urban warming drives insect pest abundance on street trees.

    PubMed

    Meineke, Emily K; Dunn, Robert R; Sexton, Joseph O; Frank, Steven D

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer. PMID:23544087

  7. Abundance measurements in stellar environments

    NASA Astrophysics Data System (ADS)

    Leone, F.

    2014-05-01

    Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

  8. Abundance measurements in stellar environments

    SciTech Connect

    Leone, F.

    2014-05-09

    Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

  9. The solar abundance of Oxygen

    NASA Astrophysics Data System (ADS)

    Grevesse, N.

    2009-07-01

    With Martin Asplund (Max Planck Institute of Astrophysics, Garching) and Jacques Sauval (Observatoire Royal de Belgique, Brussels) I recently published detailed reviews on the solar chemical composition ({Asplund et al. 2005}, {Grevesse et al. 2007}). A new one, with Pat Scott (Stockholm University) as additional co-author, will appear in Annual Review of Astronomy and Astrophysics ({Asplund et al. 2009}). Here we briefly analyze recent works on the solar abundance of Oxygen and recommend a value of 8.70 in the usual astronomical scale.

  10. LITERATURE SURVEY ON ISOTOPIC ABUNDANCE RATIO MEASUREMENTS - 2001-2005

    SciTech Connect

    HOLDEN, N.E.

    2005-08-13

    Along with my usual weekly review of the published literature for new nuclear data, I also search for new candidates for best measurements of isotopic abundances from a single source. Most of the published articles, that I previously had found in the Research Library at the Brookhaven Lab, have already been sent to the members of the Atomic Weights Commission, by either Michael Berglund or Thomas Walczyk. In the last few days, I checked the published literature for any other articles in the areas of natural variations in isotopic abundance ratios, measurements of isotopic abundance ratios on samples of extra-terrestrial material and isotopic abundance ratio measurements performed using ICPMS instruments. Hopefully this information will be of interest to members of the Commission, the sub-committee on isotopic abundance measurements (SIAM), members of the former sub-committee on natural isotopic fractionation (SNIF), the sub-committee on extra-terrestrial isotope ratios (SETIR), the RTCE Task Group and the Guidelines Task Group, who are dealing with ICPMS and TIMS comparisons. In the following report, I categorize the publications in one of four areas. Measurements performed using either positive or negative ions with Thermal Ionization Mass Spectrometer, TIMS, instruments; measurements performed on Inductively Coupled Plasma Mass Spectrometer, ICPMS, instruments; measurements of natural variations of the isotopic abundance ratios; and finally measurements on extra-terrestrial samples with instrumentation of either type. There is overlap in these areas. I selected out variations and ET results first and then categorized the rest of the papers by TIMS and ICPMS.

  11. Cationically polymerizable monomers derived from renewable sources

    SciTech Connect

    Crivello, J.V.

    1991-10-01

    The objective of this project is to make use of products obtained from renewable plant sources as monomers for the direct production of polymers which can be used for a wide range of plastic applications. In this report is described progress in the synthesis and polymerization of cationically polymerizable monomers and oligomers derived from botanical oils, terpenes, natural rubber, and lignin. Nine different botanical oils were obtained from various sources, characterized and then epoxidized. Their photopolymerization was carried out using cationic photoinitiators and the mechanical properties of the resulting polymers characterized. Preliminary biodegradation studies are being conducted on the photopolymerized films from several of these oils. Limonene was cationically polymerized to give dimers and the dimers epoxidized to yield highly reactive monomers suitable for coatings, inks and adhesives. The direct phase transfer epoxidation of squalene and natural rubber was carried out. The modified rubbers undergo facile photocrosslinking in the presence of onium salts to give crosslinked elastomers. 12 refs., 3 figs., 10 tabs.

  12. High capacity, easy release adhesives from renewable materials.

    PubMed

    Bartlett, Michael D; Crosby, Alfred J

    2014-06-01

    Reversible adhesives composed of renewable materials are presented which achieve high force capacities (810 N) while maintaining easy release (∼ 0.25 N) and reusability. These simple, non-tacky adhesives consist of natural rubber impregnated into stiff natural fiber fabrics, including cotton, hemp, and jute. This versatile approach enables a clear method for designs of environmentally-responsible, reversible adhesives for a wide variety of applications. PMID:24504650

  13. Elemental Abundances in NGC 3516

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Kraemer, S. B.; Mushotzky, R. F.; George, I. M.; Gabel, J. R.

    2003-01-01

    We present Reflection Grating Spectrometer data from an XMM-Newton observation of the Seyfert 1 galaxy NGC 3516, taken while the continuum source was in an extremely low flux state. This observation offers a rare opportunity for a detailed study of emission from a Seyfert 1 galaxy as these are usually dominated by high nuclear continuum levels and heavy absorption. The spectrum shows numerous narrow emission lines (FWHM approximately less than 1300 kilometers per second) in the 0.3 - 2 keV range, including the H-like lines of C, N, and O and the He-like lines of N, O and Ne. The emission-line ratios and the narrow width of the radiative recombination continuum of CVI indicate that the gas is photoionized and of fairly low temperature (kT approximately less than 0.01 keV). The availability of emission lines from different elements for two iso-electronic sequences allows us to constrain the element abundances. These data show that the N lines are far stronger than would be expected from gas of solar abundances. Based on our photoionization models we find that nitrogen is overabundant in the central regions of the galaxy, compared to carbon, oxygen and neon by at least a factor of 2.5. We suggest that this is the result of secondary production of nitrogen in intermediate mass stars, and indicative of the history of star formation in NGC 3516.

  14. Quinault Indian Nation Renewable Energy Plan

    SciTech Connect

    Don Hopps, Institute for Washington's Future; Jesse Nelson, Institute for Washington's Future

    2006-11-28

    The Quinault Indian Nation (Nation) initiated this study on conservation and production of renewable energy because this approach created the opportunity: • To become self-sufficient and gain greater control over the energy the Nation uses; • To generate jobs and businesses for its members; • To better manage, sustain, and protect its resources; • To express the cultural values of the Nation in an important new arena. The Nation has relatively small energy needs. These needs are concentrated at two separate points: the Quinault Beach Resort and Casino (QBRC) and Taholah on the Quinault Indian Reservation (QIR). Except for the town of Queets, energy needs are small and scattered. The needs vary greatly over the season. The small scale, widely dispersed, and variable nature of these needs presents a unique challenge to the Nation. Meeting these needs requires a resource and technology that is flexible, effective, and portable. Conservation is the most cost-effective way to meet any need. It is especially effective in a situation like this where production would leave a high per unit cost. This plan is based on first gaining energy savings through conservation. Major savings are possible through: 1. Upgrading home appliances on the QIR. 2. Weatherizing homes and facilities. 3. Changes in lighting/ventilation in the QBRC pool room. These elements of the plan are already being implemented and promise to save the Nation around a quarter of its present costs. Wood biomass is the best resource available to the QIN for energy production either on-site or for commercial development. It is abundant, flexible and portable. Its harvesting has high job potential and these jobs are a good fit for the present “skill set” of the QIN. This plan focuses on using wood biomass to produce energy and other value-added products. Our study considered various technologies and approaches to using wood for energy. We considered production for both on-site and commercial production

  15. 2011 Renewable Energy Data Book (Book)

    SciTech Connect

    Gelman, R.

    2012-10-01

    This Renewable Energy Data Book for 2011 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  16. 2012 Renewable Energy Data Book (Book)

    SciTech Connect

    Gelman, R.

    2013-10-01

    This Renewable Energy Data Book for 2012 provides facts and figures in a graphical format on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investment.

  17. 2010 Renewable Energy Data Book (Book)

    SciTech Connect

    Gelman, R.

    2011-10-01

    This Renewable Energy Data Book for 2010 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  18. 2013 Renewable Energy Data Book (Book)

    SciTech Connect

    Esterly, S.

    2014-12-01

    This Renewable Energy Data Book for 2013 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investment.

  19. 2009 Renewable Energy Data Book, August 2010

    SciTech Connect

    Not Available

    2010-08-01

    This Renewable Energy Data Book for 2009 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  20. Tandem synthesis of alternating polyesters from renewable resources

    PubMed Central

    Robert, Carine; de Montigny, Frédéric; Thomas, Christophe M.

    2011-01-01

    The vast majority of commodity materials are obtained from petrochemical feedstocks. These resources will plausibly be depleted within the next 100 years, and the peak in global oil production is estimated to occur within the next few decades. In this regard, biomass represents an abundant carbon-neutral renewable resource for the production of polymers. Here we report a new strategy, based on tandem catalysis, to obtain renewable materials. Commercially available complexes are found to be efficient catalysts for alternating polyesters from the cyclization of dicarboxylic acids followed by alternating copolymerization of the resulting anhydrides with epoxides. This operationally simple method is an attractive strategy for the production of new biodegradable polyesters. PMID:22158441

  1. Consumer Attitudes About Renewable Energy. Trends and Regional Differences

    SciTech Connect

    Bird, Lori; Sumner, Jenny

    2011-04-01

    The data in this report are taken from Natural Marketing Institute's (NMI's) Lifestyles of Health and Sustainability Consumer Trends Database. Created in 2002, the syndicated consumer database contains responses from 2,000 to 4,000 nationally representative U.S. adults (meaning the demographics of the sample are consistent with U.S. Census findings) each year. NMI used the database to analyze consumer attitudes and behavior related to renewable energy and to update previously conducted related research. Specifically, this report will explore consumer awareness, concerns, perceived benefits, knowledge of purchase options, and usage of renewable energy as well as provide regional comparisons and trends over time.

  2. Consumer Attitudes About Renewable Energy: Trends and Regional Differences

    SciTech Connect

    Natural Marketing Institute, Harleysville, Pennsylvania

    2011-04-01

    The data in this report are taken from Natural Marketing Institute's (NMI's) Lifestyles of Health and Sustainability Consumer Trends Database. Created in 2002, the syndicated consumer database contains responses from 2,000 to 4,000 nationally representative U.S. adults (meaning the demographics of the sample are consistent with U.S. Census findings) each year. NMI used the database to analyze consumer attitudes and behavior related to renewable energy and to update previously conducted related research. Specifically, this report will explore consumer awareness, concerns, perceived benefits, knowledge of purchase options, and usage of renewable energy as well as provide regional comparisons and trends over time.

  3. Nanoparticles from renewable polymers

    PubMed Central

    Wurm, Frederik R.; Weiss, Clemens K.

    2014-01-01

    The use of polymers from natural resources can bring many benefits for novel polymeric nanoparticle systems. Such polymers have a variety of beneficial properties such as biodegradability and biocompatibility, they are readily available on large scale and at low cost. As the amount of fossil fuels decrease, their application becomes more interesting even if characterization is in many cases more challenging due to structural complexity, either by broad distribution of their molecular weights (polysaccharides, polyesters, lignin) or by complex structure (proteins, lignin). This review summarizes different sources and methods for the preparation of biopolymer-based nanoparticle systems for various applications. PMID:25101259

  4. An assessment of the economic and employment impacts of the commercialization of renewable technologies in Washington/Oregon

    SciTech Connect

    Roberts, P.A.; Harrison, I.S.; Reinertsen, J.L.

    1995-11-01

    DynCorp EENSP conducted an economic impact analysis for the National Renewable Energy Laboratory, under contract to the Department of Energy Office of Utility Technologies to explore the effects on the economy and employment by deploying renewable technologies. Two regions (Texas and Washington/Oregon) with abundant renewable resources were selected for their initial evaluation of the economy and employment. This analysis investigated changes in the level of employment, effects on various industries, and changes in economic activity by simulating the addition of renewable resources to the generation mix. An economic input-output model was used to predict future economic and employment changes that are driven by renewable energy deployment in selected regions. In Washington/Oregon, the construction, and operation and maintenance (O&M) for wind, biomass stoker, biomass IGCC, geothermal, combined cycle, and combustion turbine were modeled. In order to compare the relative benefits of renewable deployment, three technology adoption scenarios were also developed to allow for the broad comparison of the {open_quotes}expected{close_quotes} or currently planned resource additions to the region with scenarios that are more renewable intensive. The deployment scenarios chosen were: Business as Usual, Renewable Intensive, and Renewable Portfolio. The results indicate that installations of renewable technologies can have a positive impact on the state economy by creating primary and secondary employment benefits.

  5. Metaproteomics reveals abundant transposase expression in mutualistic endosymbionts

    SciTech Connect

    Kleiner, Manuel; Young, Jacque C; Shah, Manesh B; Verberkmoes, Nathan C; Dubilier, Nicole

    2013-01-01

    Transposases, enzymes that catalyze the movement of mobile genetic elements, are the most abundant genes in nature. While many bacteria encode an abundance of transposases in their genomes, the current paradigm is that transposase gene expression is tightly regulated and generally low due to its severe mutagenic effects. In the current study, we detected the highest number of transposase proteins ever reported in bacteria, in symbionts of the gutless marine worm Olavius algarvensis using metaproteomics. At least 26 different transposases from 12 different families were detected and genomic and proteomic analyses suggest many of these are active. This high expression of transposases indicates that the mechanisms for their tight regulation have been disabled or destroyed. Based on recent studies on other symbionts and pathogens that showed high transposase transcription, we speculate that abundant transposase expression might be common in symbionts and pathogens.

  6. Abundance patterns in planetary nebulae

    NASA Astrophysics Data System (ADS)

    Henry, Richard B. C.

    1990-06-01

    Abundances of He, N, O, and Ne have been uniformly calculated for 192 planetary nebulas residing in the Galactic disk and halo, the LMC, the SMC, and M31. Direct correlations appear to exist for type I as well as non-type I objects for the following pairs of parameters: N/O-He/H, N/O-N/H, and Ne/H-O/H. Separately, type I planetaries show a weak anticorrelation between N/O and O/H, while non-type I's exhibit direct correlations between N/H and O/H and between N/O and O/H. From these patterns, it is inferred that non-type I's synthesize N via the CN cycle. Type I planetaries, on the other hand, manufacture N at least partially via the ON cycle, destroying O in the process. Neither type appears to synthesize O or Ne.

  7. Biosynthesis of planet friendly bioplastics using renewable carbon source.

    PubMed

    Jain, Roopesh; Tiwari, Archana

    2015-01-01

    Plastics are uniquely flexible materials that offer considerable benefits as a simple packing to complex engineering material. Traditional synthetic polymers (often called plastics), such as polypropylene and polyethylene have been derived from non-renewable petrochemicals and known to cause environmental concerns due to their non-biodegradable nature. The enormous use of petroleum-based plastic compounds emphasized a need for sustainable alternatives derived from renewable resources. Bioplastics have attracted widespread attention, as eco-friendly and eco-tolerable alternative. But they have got certain limitations as well, such as high cost of production and unsatisfactory mechanical properties. In this study we have found agriculture waste (AW) as low-cost and renewable substrate for the production of bioplastics in bacterial fermentation. Improvement in tensile properties of produced bioplastic film has also been documented upon blending with Cellulose Acetate Butyrate (CAB). PMID:25717378

  8. Thorium: Crustal abundance, joint production, and economic availability

    DOE PAGESBeta

    Jordan, Brett W.; Eggert, Roderick G.; Dixon, Brent W.; Carlsen, Brett W.

    2015-03-02

    Recently, interest in thorium's potential use in a nuclear fuel cycle has been renewed. Thorium is more abundant, at least on average, than uranium in the earth's crust and, therefore, could theoretically extend the use of nuclear energy technology beyond the economic limits of uranium resources. This paper provides an economic assessment of thorium availability by creating cumulative-availability and potential mining-industry cost curves, based on known thorium resources. These tools provide two perspectives on the economic availability of thorium. In the long term, physical quantities of thorium likely will not be a constraint on the development of a thorium fuelmore » cycle. In the medium term, however, thorium supply may be limited by constraints associated with its production as a by-product of rare earth elements and heavy mineral sands. As a result, environmental concerns, social issues, regulation, and technology also present issues for the medium and long term supply of thorium.« less

  9. Thorium: Crustal abundance, joint production, and economic availability

    SciTech Connect

    Jordan, Brett W.; Eggert, Roderick G.; Dixon, Brent W.; Carlsen, Brett W.

    2015-03-02

    Recently, interest in thorium's potential use in a nuclear fuel cycle has been renewed. Thorium is more abundant, at least on average, than uranium in the earth's crust and, therefore, could theoretically extend the use of nuclear energy technology beyond the economic limits of uranium resources. This paper provides an economic assessment of thorium availability by creating cumulative-availability and potential mining-industry cost curves, based on known thorium resources. These tools provide two perspectives on the economic availability of thorium. In the long term, physical quantities of thorium likely will not be a constraint on the development of a thorium fuel cycle. In the medium term, however, thorium supply may be limited by constraints associated with its production as a by-product of rare earth elements and heavy mineral sands. As a result, environmental concerns, social issues, regulation, and technology also present issues for the medium and long term supply of thorium.

  10. Renewable Energy and Climate Change

    SciTech Connect

    Chum, H. L.

    2012-01-01

    The Intergovernmental Panel on Climate Change issued the Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) at http://srren.ipcc-wg3.de/ (May 2011 electronic version; printed form ISBN 978-1-107-60710-1, 2012). More than 130 scientists contributed to the report.* The SRREN assessed existing literature on the future potential of renewable energy for the mitigation of climate change within a portfolio of mitigation options including energy conservation and efficiency, fossil fuel switching, RE, nuclear and carbon capture and storage (CCS). It covers the six most important renewable energy technologies - bioenergy, direct solar, geothermal, hydropower, ocean and wind, as well as their integration into present and future energy systems. It also takes into consideration the environmental and social consequences associated with these technologies, the cost and strategies to overcome technical as well as non-technical obstacles to their application and diffusion.

  11. Oceanic heterotrophic dinoflagellates: distribution, abundance, and role as microzooplankton

    SciTech Connect

    Lessard, E.J.

    1984-01-01

    The primary objectives of this thesis were to determine the distribution and abundance of heterotrophic dinoflagellates across the Gulf Stream system off Cape Hatteras and to assess the potential grazing impact of these microheterotrophs in plankton communities. A list of species encountered in this study and their trophic status based on epifluorescence is presented, as well as observations on the presence of external or internal symbionts. The abundance of heterotrophic dinoflagellates across the Gulf Stream region off Cape Hatteras was determined from bimonthly net tow samples over a year and from whole water samples in March. Their average abundance was twice that of net ciliates in the net plankton and ten times that of ciliates in the nanoplankton. An isotope technique was developed to measure grazing rates of individual dinoflaggellates and other microzooplankton which cannot be separated in natural populations on the basis of size. /sup 3/H-thymidine and /sup 14/C-bicarbonate were used to label natural heterotrophic (bacteria and bacterivores) and autotrophic (phytoplankton and herbivores) food, respectively. Estimates of the grazing impact of heterotrophic kinoflagellates relative to other groups of heterotrophs on phytoplankton and bacteria were made by combining abundance data and clearance rates. Such calculations suggested that heterotrophic dinoflagellates may be an important group of grazers in oceanic waters.

  12. Lithium Abundance in Planet Search Stars

    NASA Astrophysics Data System (ADS)

    Myles, Justin; Yale Exoplanets

    2016-01-01

    Since most lithium in the universe is primordial and is destroyed in stars, lithium abundance can be used as a stellar age indicator. Some research seems to show that planet formation may also affect lithium abundance in exoplanet host stars (EHS). However, small and heterogenous samples have made both of these phenomena unclear. Further study of lithium abundance in EHS is needed to better understand possible physical roles of lithium in planet formation theory. We use a large homogenous sample with accurate stellar parameters on which we will use equivalent width analysis to determine precise lithium abundances. From these abundance values we determine an age vs. abundance relation. Additionally, we aim to explore correlation between lithium abundance and planet formation.

  13. Who Owns Renewable Energy Certificates?

    SciTech Connect

    Holt, Edward; Wiser, Ryan; Bolinger, Mark

    2006-06-01

    Renewable energy certificates (RECs) are tradable instruments that convey the attributes of a renewable energy generator and the right to make certain claims about energy purchases. RECs first appeared in US markets in the late 1990s and are particularly important in states that accept or require them as evidence of compliance with renewables portfolio standards (RPS). The emergence of RECs as a tradable commodity has made utilities, generators, and regulators increasingly aware of the need to specify who owns the RECs in energy transactions. In voluntary transactions, most agree that the question of REC ownership can and should be negotiated privately between the buyer and the seller, and should be clearly established by contract. Claims about purchasing or using renewable energy should only be made if REC ownership can be documented. In many other cases, however, renewable energy transactions are either mandated or encouraged through state or federal policy. Because of the recent appearance of RECs, legislation and regulation mandating the purchase of renewable energy has sometimes been silent on the disposition of the RECs associated with that generation. Furthermore, some renewable energy contracts pre-date the existence of RECs, and therefore do not address REC ownership. In both of these instances, the issue of REC ownership must often be answered by legislative or regulatory authorities. The resulting uncertainty in REC ownership has hindered the development of robust REC markets and has, in some cases, led to contention between buyers and sellers of renewable generation. This article, which is based on a longer Berkeley Lab report, reviews federal and state efforts to clarify the ownership of RECs from Qualifying Facilities (QFs) that sell their generation under the Public Utility Regulatory Policies Act (PURPA) of 1978. The full report also addresses state efforts to clarify REC ownership in two other situations, customer-owned generation that benefits

  14. Surface abundances of ON stars

    NASA Astrophysics Data System (ADS)

    Martins, F.; Simón-Díaz, S.; Palacios, A.; Howarth, I.; Georgy, C.; Walborn, N. R.; Bouret, J.-C.; Barbá, R.

    2015-06-01

    Context. Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material is observed at the surface of O and B stars. Aims: ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle is not known. Our goal is to answer this question. Methods: We performed a spectroscopic analysis of a sample of ON stars with atmosphere models. We determined the fundamental parameters as well as the He, C, N, and O surface abundances. We also measured the projected rotational velocities. We compared the properties of the ON stars to those of normal O stars. Results: We show that ON stars are usually rich in helium. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cannot account for the extreme enrichment observed among ON main sequence stars. Some ON stars are members of binary systems, but others are single stars as indicated by stable radial velocities. Mass transfer is therefore not a simple explanation for the observed chemical properties. Conclusions: We conclude that ON stars show extreme chemical enrichment at their surface, consistent with nucleosynthesis through the CNO cycle. Its origin is not clear at present. Based on observations obtained 1) at the Anglo-Australian Telescope; 2) at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii; 3) at the ESO/La Silla Observatory under programs 081.D-2008, 083.D-0589, 086.D-0997; 4) the Nordic Optical Telescope, operated on the island of La

  15. Renewable energy implementation at Channel Islands National Park

    SciTech Connect

    Bullard, K.

    1997-12-31

    With facilities located 14 to 60 miles (22 to 96 km) offshore, Channel Islands National Park naturally lends itself to the implementation of renewable energy projects in many locations. The park first began utilizing photovoltaics in the early 1970`s for communications at remote locations and presently has fifty-seven applications in operation. Renewable Energy systems have proven to be a reliable, cost efficient and environmentally friendly way of conducting business. They now provide the park with power for remote facility operations, water pumping, resource monitoring and communications. Currently the park has 29 kW of photovoltaics and 21.5 kW of wind generation in operation, with additional installations planned for the immediate future. Visitors to Channel Islands National Park have the opportunity to see renewable energy applications in use on all the park islands. The parks extensive utilization of renewables has educated the public about the practical uses of alternative energy and demonstrated the parks commitment to reducing dependence on non-renewable resources.

  16. Strategies for promoting renewables in a new electric industry

    SciTech Connect

    Driver, B.

    1996-12-31

    This paper describes strategies for promoting renewable resources in an era characterized by competitive pressures in the electric industry. It begins with a background section to describe the perspective from which I am writing and the nature of the pressures confronting renewables in 1996. Then, the paper turns to a discussion of the regulatory and other options to promote renewables in this environment. The major conclusion of the paper is that there is no {open_quotes}magic bullet{close_quotes} to guide the development of renewables through the developing competitive era within the electric industry. Indeed, it appears that the job can get done only through a combination of different measures at all levels of government. The author believes that among the most effective measures are likely to be: a national renewable resources generation standard; conditions attached to restructuring events; regional interstate compacts; regional risk-sharing consortia supported by federal and state tax and fiscal policy; and state {open_quotes}systems benefits charges;{close_quotes}

  17. Significant biases affecting abundance determinations

    NASA Astrophysics Data System (ADS)

    Wesson, Roger

    2015-08-01

    I have developed two highly efficient codes to automate analyses of emission line nebulae. The tools place particular emphasis on the propagation of uncertainties. The first tool, ALFA, uses a genetic algorithm to rapidly optimise the parameters of gaussian fits to line profiles. It can fit emission line spectra of arbitrary resolution, wavelength range and depth, with no user input at all. It is well suited to highly multiplexed spectroscopy such as that now being carried out with instruments such as MUSE at the VLT. The second tool, NEAT, carries out a full analysis of emission line fluxes, robustly propagating uncertainties using a Monte Carlo technique.Using these tools, I have found that considerable biases can be introduced into abundance determinations if the uncertainty distribution of emission lines is not well characterised. For weak lines, normally distributed uncertainties are generally assumed, though it is incorrect to do so, and significant biases can result. I discuss observational evidence of these biases. The two new codes contain routines to correctly characterise the probability distributions, giving more reliable results in analyses of emission line nebulae.

  18. Renewable Energy Cost Optimization Spreadsheet

    2007-12-31

    The Software allow users to determine the optimum combination of renewable energy technologies to minimize life cycle cost for a facility by employing various algorithms which calculate initial and operating cost, energy delivery, and other attributes associated with each technology as a function of size.

  19. Renewable Energy for Rural Schools.

    ERIC Educational Resources Information Center

    Jimenez, Antonio C.; Lawand, Tom

    Although education in rural communities is an important priority, in many cases, electricity is not available to support rural educational activities. Renewable energy systems present a reasonable solution to support activities such as lighting, computers, telecommunications, and distance learning. There are certain factors and criteria that need…

  20. 75 FR 26919 - Charter Renewals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... Committee on Commercial Remote Sensing Charter. SUMMARY: In accordance with the provisions of the Federal... Commerce has determined that the renewal of the Advisory Committee on Commercial Remote Sensing (ACCRES) is... relating to the U.S. commercial remote-sensing industry and NOAA's activities to carry out...

  1. Renewable energy from urban landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Utilizing biomass from urban landscapes could significantly contribute to the nation’s renewable energy needs. In 2007, an experiment was begun to evaluate the biomass potential from a bermudagrass, Cynodon dactylon var. dactylon (L.) Pers., lawn in Woodward, OK and to estimate the potential biomas...

  2. The potential of renewable energy

    SciTech Connect

    Not Available

    1990-03-01

    On June 27 and 28, 1989, the US Department of Energy (DOE) national laboratories were convened to discuss plans for the development of a National Energy Strategy (NES) and, in particular, the analytic needs in support of NES that could be addressed by the laboratories. As a result of that meeting, interlaboratory teams were formed to produce analytic white papers on key topics, and a lead laboratory was designated for each core laboratory team. The broad-ranging renewables assignment is summarized by the following issue statement from the Office of Policy, Planning and Analysis: to what extent can renewable energy technologies contribute to diversifying sources of energy supply What are the major barriers to greater renewable energy use and what is the potential timing of widespread commercialization for various categories of applications This report presents the results of the intensive activity initiated by the June 1989 meeting to produce a white paper on renewable energy. Scores of scientists, analysts, and engineers in the five core laboratories gave generously of their time over the past eight months to produce this document. Their generous, constructive efforts are hereby gratefully acknowledged. 126 refs., 44 figs., 32 tabs.

  3. Solar Renewable Energy. Teaching Unit.

    ERIC Educational Resources Information Center

    Buchanan, Marion; And Others

    This unit develops the concept of solar energy as a renewable resource. It includes: (1) an introductory section (developing understandings of photosynthesis and impact of solar energy); (2) information on solar energy use (including applications and geographic limitations of solar energy use); and (3) future considerations of solar energy…

  4. Issues in Renewable Energy Education

    ERIC Educational Resources Information Center

    Thomas, Chacko; Jennings, Philip; Lloyd, Bob

    2008-01-01

    Renewable energy education is evolving rapidly in response to drivers such as oil depletion and global warming. There is a rapidly increasing level of student interest in these topics and a growing demand from industry and government for skilled personnel to develop sustainable energy systems and greenhouse solutions. Several Australian and New…

  5. Shapes of a Renewable Society.

    ERIC Educational Resources Information Center

    Deudney, Daniel; Flavin, Christopher

    1983-01-01

    To rely on coal and nuclear power as sources of energy is to narrow society's future options and to present numerous problems. Renewable solar energy, on the other hand, can preserve rather than reduce options. More jobs, rising self-reliance, and new equalities between nations will be the result. (RM)

  6. Renewable and sustainable transportation fuels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper outlined the bioenergy research and production history as well as current status of renewable and sustainable transportation fuels in U.S. From starch based ethanol (first generation biofuel) to cellulosic ethanol (second generation biofuel), evident progress have been made in the past d...

  7. PEV Integration with Renewables (Presentation)

    SciTech Connect

    Markel, T.

    2014-06-18

    This presentation discusses current research at NREL on integrating plug-in electric vehicles with the grid and using renewable energy to charge the grid. The Electric Vehicle Grid Integration (EVGI) and Integrated Network Testbed for Energy Grid Research and Technology Experimentation (INTEGRATE) are addressing the opportunities and technical requirements for vehicle grid integration that will increase marketability and lead to greater petroleum reduction.

  8. Sprayed Coating Renews Butyl Rubber

    NASA Technical Reports Server (NTRS)

    Martin, R. B.

    1982-01-01

    Damaged butyl rubber products are renewed by spray technique originally developed for protective suits worn by NASA workers. A commercial two-part adhesive is mixed with Freon-113 (or equivalent) trichlorotrifluoroethane to obtain optimum viscosity for spraying. Mix is applied with an external-air-mix spray gun.

  9. Analysis of renewable portfolio standards

    SciTech Connect

    Bernow, S.; Dougherty, W.; Duckworth, M.

    1997-12-31

    A national RPS would increase the fraction of U.S. electricity generation from renewable technologies at least cost. It would help ensure that the cost and performance of these technologies would improve with manufacturing experience, scale economies, and learning-by-doing from their integration into electric systems. Thus, their economic, environmental, energy security, and sustainability benefits would be realized.

  10. Renewable energy in Indian country

    SciTech Connect

    1995-12-31

    On June 25--27, 1995, at Mesa Verde National Park in southwestern Colorado, the Center for Resource Management (CRM), organized and sponsored a conference in conjunction with the Navajo Nation, EPA, and Bechtel Group, Inc., to deal with issues associated with developing renewable energy resources on Indian lands. Due to the remoteness of many reservation homes and the cost of traditional power line extensions, a large percentage of the Indian population is today without electricity or other energy services. In addition, while they continue to develop energy resources for export, seeing only minimal gain in their own economies, Indian people are also subject to the health and environmental consequences associated with proximity to traditional energy resource development. Renewable energy technologies, on the other hand, are often ideally suited to decentralized, low-density demand. These technologies--especially solar and wind power--have no adverse health impacts associated with generation, are relatively low cost, and can be used in applications as small as a single home, meeting power needs right at a site. Their minimal impact on the environment make them particularly compatible with American Indian philosophies and lifestyles. Unfortunately, the match between renewable energy and Indian tribes has been hampered by the lack of a comprehensive, coordinated effort to identify renewable energy resources located on Indian lands, to develop practical links between Indian people`s needs and energy producers, and to provide the necessary training for tribal leaders and members to plan, implement, and maintain renewable energy systems. Summaries of the presentations are presented.

  11. Renewables for sustainable village power

    SciTech Connect

    Flowers, L

    1997-03-01

    It is estimated that two billion people live without electricity and its services. In addition, there is a sizeable number of rural villages that have limited electrical service, with either part-day operation by diesel gen-sets or partial electrification (local school or community center and several nearby houses). For many villages connected to the grid, power is often sporadically available and of poor quality. The U.S. National Renewable Energy Laboratory (NREL) in Golden, Colorado, has initiated a program to address these potential electricity opportunities in rural villages through the application of renewable energy (RE) technologies. The objective of this program is to develop and implement applications that demonstrate the technical performance, economic competitiveness, operational viability, and environmental benefits of renewable rural electric solutions, compared to the conventional options of line extension and isolated diesel mini-grids. These four attributes foster sustainability; therefore, the program is entitled Renewables for Sustainable Village Power (RSVP). The RSVP program is a multi-technology, multi-application program composed of six activities, including village applications development, computer model development, systems analysis, pilot project development, technical assistance, and Internet-based village power project data base. While the current program emphasizes wind, photovoltaics (PV), and their hybrids with diesel gen-sets, micro-hydro and micro-biomass technologies may be integrated in the future. NREL`s RSVP team is currently involved in rural electricity projects in thirteen countries, with U.S., foreign, and internationally based agencies and institutions. The integration of the technology developments, institutional experiences, and the financial solutions for the implementation of renewables in the main line rural electrification processes in both the developing world and remote regions of the developed world is the goal.

  12. High Abundance of Ions in Cosmic Ices

    NASA Technical Reports Server (NTRS)

    Gudipati, Murthy S.; Allamandola, Louis J.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Water-rich, mixed molecular ices and polycyclic aromatic hydrocarbons (PAHs) are common throughout interstellar molecular clouds and the Solar System. Vacuum ultraviolet (VUV) irradiation and particle bombardment of these abiotic ices produces complex organic species, including important biogenic molecules such as amino acids and functionalized PAHs which may have played a role in the origin of life. This ability of such water-rich, oxygen dominated ices to promote production of complex organic species is surprising and points to an important, unusual, but previously overlooked mechanism at play within the ice. Here we report the nature of this mechanism using electronic spectroscopy. VUV-irradiation of PAH/H2O ices leads to an unprecedented and efficient (greater than 70 %) conversion of the neutral PAHs to their cation form (PAH+). Further, these H2O/PAH+ ices are stabile at temperatures below 50 K, a temperature domain common throughout interstellar clouds and the Solar System. Between 50 and 125 K they react to form the complex organics. In view of this, we conclude that charged PAHs and other molecular ions should be common and abundant in many cosmic ices. The chemical, spectroscopic and physical properties of these ion-rich ices can be of fundamental importance for objects as diverse as comets, planets, and molecular clouds and may account for several poorly understood phenomena associated with each of these object classes.

  13. Operation and planning of coordinated natural gas and electricity infrastructures

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaping

    Natural gas is becoming rapidly the optimal choice for fueling new generating units in electric power system driven by abundant natural gas supplies and environmental regulations that are expected to cause coal-fired generation retirements. The growing reliance on natural gas as a dominant fuel for electricity generation throughout North America has brought the interaction between the natural gas and power grids into sharp focus. The primary concern and motivation of this research is to address the emerging interdependency issues faced by the electric power and natural gas industry. This thesis provides a comprehensive analysis of the interactions between the two systems regarding the short-term operation and long-term infrastructure planning. Natural gas and renewable energy appear complementary in many respects regarding fuel price and availability, environmental impact, resource distribution and dispatchability. In addition, demand response has also held the promise of making a significant contribution to enhance system operations by providing incentives to customers for a more flat load profile. We investigated the coordination between natural gas-fired generation and prevailing nontraditional resources including renewable energy, demand response so as to provide economical options for optimizing the short-term scheduling with the intense natural gas delivery constraints. As the amount and dispatch of gas-fired generation increases, the long-term interdependency issue is whether there is adequate pipeline capacity to provide sufficient gas to natural gas-fired generation during the entire planning horizon while it is widely used outside the power sector. This thesis developed a co-optimization planning model by incorporating the natural gas transportation system into the multi-year resource and transmission system planning problem. This consideration would provide a more comprehensive decision for the investment and accurate assessment for system adequacy and

  14. Renewable Energy Resources in the United Kingdom.

    ERIC Educational Resources Information Center

    Roberts, Michael J.; Thomas, M. Pugh

    1990-01-01

    This paper defines renewable energy and outlines possible sources of this energy. Supplies, and ethics are considered. The position of renewable energy sources in the energy policy of Great Britain are discussed. (CW)

  15. Impacts of a 15% Renewable Portfolio Standard

    EIA Publications

    2007-01-01

    This analysis responds to a request from Senator Jeff Bingaman that the Energy Information Administration (EIA) analyze a renewable portfolio standard (RPS) requiring that 15% of U.S. electricity sales be derived from qualifying renewable energy resources.

  16. Renewable Energy Park - Preliminary Feasibility & Engineering Report

    SciTech Connect

    Ariwite, Roderick

    2015-07-31

    This "Renewable Energy Park - Preliminary Feasibility & Engineering Report" seeks to provide an overall assessment and review of renewable energy development opportunities on the Fallon Indian Reservation and Colony Lands.

  17. Renewable Energy: Ready to Meet Its Promise?

    SciTech Connect

    Bull, S. R.; Billman, L. L.

    1999-01-01

    This paper will briefly review the technical status, cost, and applications of major renewable energy technologies in 1998, and also discuss some of the socioeconomic impacts of wide-scale adoption of renewables.

  18. Biodegradable polyester films from renewable aleuritic acid: surface modifications induced by melt-polycondensation in air

    NASA Astrophysics Data System (ADS)

    Jesús Benítez, José; Alejandro Heredia-Guerrero, José; Inmaculada de Vargas-Parody, María; Cruz-Carrillo, Miguel Antonio; Morales-Flórez, Victor; de la Rosa-Fox, Nicolás; Heredia, Antonio

    2016-05-01

    Good water barrier properties and biocompatibility of long-chain biopolyesters like cutin and suberin have inspired the design of synthetic mimetic materials. Most of these biopolymers are made from esterified mid-chain functionalized ω-long chain hydroxyacids. Aleuritic (9,10,16-trihydroxypalmitic) acid is such a polyhydroxylated fatty acid and is also the major constituent of natural lac resin, a relatively abundant and renewable resource. Insoluble and thermostable films have been prepared from aleuritic acid by melt-condensation polymerization in air without catalysts, an easy and attractive procedure for large scale production. Intended to be used as a protective coating, the barrier's performance is expected to be conditioned by physical and chemical modifications induced by oxygen on the air-exposed side. Hence, the chemical composition, texture, mechanical behavior, hydrophobicity, chemical resistance and biodegradation of the film surface have been studied by attenuated total reflection–Fourier transform infrared spectroscopy (ATR–FTIR), atomic force microscopy (AFM), nanoindentation and water contact angle (WCA). It has been demonstrated that the occurrence of side oxidation reactions conditions the surface physical and chemical properties of these polyhydroxyester films. Additionally, the addition of palmitic acid to reduce the presence of hydrophilic free hydroxyl groups was found to have a strong influence on these parameters.

  19. An economic and ecological perspective of ethanol production from renewable agro waste: a review.

    PubMed

    Bhatia, Latika; Johri, Sonia; Ahmad, Rumana

    2012-01-01

    Agro-industrial wastes are generated during the industrial processing of agricultural products. These wastes are generated in large amounts throughout the year, and are the most abundant renewable resources on earth. Due to the large availability and composition rich in compounds that could be used in other processes, there is a great interest on the reuse of these wastes, both from economical and environmental view points. The economic aspect is based on the fact that such wastes may be used as low-cost raw materials for the production of other value-added compounds, with the expectancy of reducing the production costs. The environmental concern is because most of the agro-industrial wastes contain phenolic compounds and/or other compounds of toxic potential; which may cause deterioration of the environment when the waste is discharged to the nature. Although the production of bioethanol offers many benefits, more research is needed in the aspects like feedstock preparation, fermentation technology modification, etc., to make bioethanol more economically viable. PMID:23217124

  20. An economic and ecological perspective of ethanol production from renewable agro waste: a review

    PubMed Central

    2012-01-01

    Agro-industrial wastes are generated during the industrial processing of agricultural products. These wastes are generated in large amounts throughout the year, and are the most abundant renewable resources on earth. Due to the large availability and composition rich in compounds that could be used in other processes, there is a great interest on the reuse of these wastes, both from economical and environmental view points. The economic aspect is based on the fact that such wastes may be used as low-cost raw materials for the production of other value-added compounds, with the expectancy of reducing the production costs. The environmental concern is because most of the agro-industrial wastes contain phenolic compounds and/or other compounds of toxic potential; which may cause deterioration of the environment when the waste is discharged to the nature. Although the production of bioethanol offers many benefits, more research is needed in the aspects like feedstock preparation, fermentation technology modification, etc., to make bioethanol more economically viable. PMID:23217124

  1. Abundance of introduced species at home predicts abundance away in herbaceous communities

    USGS Publications Warehouse

    Firn, Jennifer; Moore, Joslin L.; MacDougall, Andrew S.; Borer, Elizabeth T.; Seabloom, Eric W.; HilleRisLambers, Janneke; Harpole, W. Stanley; Cleland, Elsa E.; Brown, Cynthia S.; Knops, Johannes M.H.; Prober, Suzanne M.; Pyke, David A.; Farrell, Kelly A.; Bakker, John D.; O'Halloran, Lydia R.; Adler, Peter B.; Collins, Scott L.; D'Antonio, Carla M.; Crawley, Michael J.; Wolkovich, Elizabeth M.; La Pierre, Kimberly J.; Melbourne, Brett A.; Hautier, Yann; Morgan, John W.; Leakey, Andrew D.B.; Kay, Adam; McCulley, Rebecca; Davies, Kendi F.; Stevens, Carly J.; Chu, Cheng-Jin; Holl, Karen D.; Klein, Julia A.; Fay, Phillip A.; Hagenah, Nicole; Kirkman, Kevin P.; Buckley, Yvonne M.

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.

  2. A College-School Connection to Renewal.

    ERIC Educational Resources Information Center

    Pryor, Bonnie

    The National Network for Educational Renewal (NNER) consists of higher education institutions and partner K-12 schools promoting simultaneous renewal of teacher education and K-12 schools. The network helps renew teacher education by preparing educators who will: (1) provide all students with equitable opportunities for becoming educated,…

  3. 10 CFR 76.36 - Renewals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Renewals. 76.36 Section 76.36 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Application § 76.36 Renewals. (a) The Corporation shall file periodic applications for renewal, as required by § 76.31. (b) Information contained...

  4. 10 CFR 76.36 - Renewals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Renewals. 76.36 Section 76.36 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Application § 76.36 Renewals. (a) The Corporation shall file periodic applications for renewal, as required by § 76.31. (b) Information contained...

  5. 10 CFR 76.36 - Renewals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Renewals. 76.36 Section 76.36 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Application § 76.36 Renewals. (a) The Corporation shall file periodic applications for renewal, as required by § 76.31. (b) Information contained...

  6. 10 CFR 76.36 - Renewals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Renewals. 76.36 Section 76.36 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Application § 76.36 Renewals. (a) The Corporation shall file periodic applications for renewal, as required by § 76.31. (b) Information contained...

  7. 10 CFR 76.36 - Renewals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Renewals. 76.36 Section 76.36 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Application § 76.36 Renewals. (a) The Corporation shall file periodic applications for renewal, as required by § 76.31. (b) Information contained...

  8. Abundance Gradients in Clusters of Galaxies

    NASA Astrophysics Data System (ADS)

    Dupke, Renato De Alencar

    This dissertation presents the analysis of spatially resolved ASCA satellite X-ray spectra for four clusters of galaxies (Abell 496, Abell 2199, Abell 3571 and Abell 1060). The abundance distributions of Abell 496, Abell 2199 and Abell 3571 are shown to be centrally enhanced. The distribution of elemental abundance ratios, combined with calculations of supernovae rates, shows that the central abundance enhancement in these galaxy clusters is dominated by supernova, Type 1a iron, while the outer parts are dominated by supernovae Type II iron and the most likely mechanism proposed to produce this central iron is ram-pressure stripping, rather than accumulated stellar mass loss from the central dominant galaxy. At least 50% (by mass) of the iron in the central regions is from supernovae Type Ia, varying slightly from cluster to cluster. Although the analysis of Abell 1060 reveals no significant central abundance enhancement, supernovae Type Ia are shown to contribute significantly to the iron content of the central regions. However, accumulated stellar mass loss from the two central dominant galaxies in this cluster can account for all of the supernovae Type la iron in the central regions. The nickel to iron abundance ratio shows that delayed detonation explosion models for supernovae Type la are inconsistent with the observed abundance ratios in the inner regions of Abell 496, Abell 2199 and Abell 3571. A comparison of the distributions of iron mass and the luminosity of early type galaxies in four clusters, three of them having central abundance enhancements (Virgo, Abell 496 and Centaurus) and one having a flat abundance distribution (Coma), indicates that the iron mass traces the luminosity of early type galaxies in abundance gradient clusters better than in flat abundance clusters. This suggests that abundance gradients can be washed out by cluster mergers.

  9. Analysis of a 10% Renewable Portfolio Standard, Supplement to

    EIA Publications

    2003-01-01

    On June 10, 2003, Senator Pete Domenici, Chairman of the Senate Committee on Energy and Natural Resources, requested additional analysis of a Renewable Portfolio Standard (RPS), expected to be proposed as an amendment to energy legislation currently pending before the U.S. Senate. This request asked the Energy Information Administration (EIA) to provide additional results from two previously released EIA analyses of the proposed legislation, and to conduct further analyses with modified assumptions.

  10. Renewable-Biomolecule-Based Full Lithium-Ion Batteries.

    PubMed

    Hu, Pengfei; Wang, Hua; Yang, Yun; Yang, Jie; Lin, Jie; Guo, Lin

    2016-05-01

    A renewable-biomolecule-based full lithium-ion battery is successfully fabricated for the first time. Naturally derivable emodin and humic acid based electrodes are used as cathode and anode, respectively. The as-assembled batteries exhibit superb specific capacity and substantial operating voltage capable of powering a wearable electronic watch, suggesting the great potential for practical applications with the significant merits of sustainability and biocompatibility. PMID:26989989

  11. Alkene Metathesis and Renewable Materials: Selective Transformations of Plant Oils

    NASA Astrophysics Data System (ADS)

    Malacea, Raluca; Dixneuf, Pierre H.

    The olefin metathesis of natural oils and fats and their derivatives is the basis of clean catalytic reactions relevant to green chemistry processes and the production of generate useful chemicals from renewable raw materials. Three variants of alkene metathesis: self-metathesis, ethenolysis and cross-metathesis applied to plant oil derivatives will show new routes to fine chemicals, bifunctional products, polymer precursours and industry intermediates.

  12. Photon Science for Renewable Energy

    SciTech Connect

    Hussain, Zahid; Tamura, Lori; Padmore, Howard; Schoenlein, Bob; Bailey, Sue

    2010-03-31

    Our current fossil-fuel-based system is causing potentially catastrophic changes to our planet. The quest for renewable, nonpolluting sources of energy requires us to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels. Light-source facilities - the synchrotrons of today and the next-generation light sources of tomorrow - are the scientific tools of choice for exploring the electronic and atomic structure of matter. As such, these photon-science facilities are uniquely positioned to jump-start a global revolution in renewable and carbonneutral energy technologies. In these pages, we outline and illustrate through examples from our nation's light sources possible scientific directions for addressing these profound yet urgent challenges.

  13. Customer choice and renewable energy

    SciTech Connect

    Schaefer, D.

    1996-12-31

    Opinions on political and social factors affecting the U.S. market for wind power are presented in this paper. The position of and activities taken by U.S. Congressman Dan Schaefer as Chairman of the House Energy and Power Subcommittee are outlined. Background information used as input to subcommittee hearings is summarized. The formation and activities of the House Renewable Energy Caucus are very briefly described.

  14. RP-5 RENEWABLE ENERGY PROJECT

    SciTech Connect

    Neil Clifton, P.E.; Eliza Jane Whitman; Jamal A. Zughbi, P.E.

    2002-10-30

    This report is the first quarterly technical report for the RP-5 Renewable Energy Project. The report summarizes the work progress, effort and activities that took place during the period of July 12, 2002 (project inception) to September 30, 2002. The report has been prepared in accordance with the Department of Energy (DOE) Guidelines. This technical report covers all meetings and discussions that were conducted to identify and analyze potential renewable energy technologies and verify its feasibility and suitability for the project. The report covers the two-day Energy Charrette that was held at the Inland Empire Utilities Agency (IEUA) Headquarters Building on May 8-9, 2002 to brainstorm, evaluate and present all available renewable energy options along with their implementations. Although the Energy Charrette was held prior to awarding of the DOE Grant, the outcome of the Charrette forms the basis of the activities that took place after July 12, 2002. Therefore, the Energy Charrette is frequently referenced and discussed in this report. The report also discusses the Energy Meeting that took place on September 24, 2002 between IEUA and CH2M Hill to follow up on the various presentations and recommendations resulting from the Energy Charrette. It should be noted that no final equipment data or capacities have been presented in the report, as the Conceptual Design has not started yet. This report covers continuing effort and work to complete the Request for Proposal (RFP) for this project. The Executive Summary Section covers more details on the scope of work, which consists of the conceptual, preliminary and final design, and what has been accomplished during the report period. Tools and methods utilized in this project to identify renewable energy technologies are included in the ''Experimental'' Section. Finally, Project achievements, implications and importance in improving this kind of technology are summarized in the ''Conclusion'' Section.

  15. Climate and local abundance in freshwater fishes

    PubMed Central

    Knouft, Jason H.; Anthony, Melissa M.

    2016-01-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  16. Climate and local abundance in freshwater fishes.

    PubMed

    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  17. Renewable energy delivery systems and methods

    DOEpatents

    Walker, Howard Andrew

    2013-12-10

    A system, method and/or apparatus for the delivery of energy at a site, at least a portion of the energy being delivered by at least one or more of a plurality of renewable energy technologies, the system and method including calculating the load required by the site for the period; calculating the amount of renewable energy for the period, including obtaining a capacity and a percentage of the period for the renewable energy to be delivered; comparing the total load to the renewable energy available; and, implementing one or both of additional and alternative renewable energy sources for delivery of energy to the site.

  18. Renewable energy annual 1997. Volume 1

    SciTech Connect

    1998-02-01

    This report presents information on renewable energy consumption, capacity, and electricity generation data, as well as data on US solar thermal and photovoltaic collector manufacturing activities. The renewable energy resources included in the report are: biomass (wood, ethanol, and biodiesel); municipal solid waste; geothermal; wind; and solar (solar thermal and photovoltaic). The first chapter of the report provides an overview of renewable energy use and capability from 1992 through 1996. It contains renewable energy consumption, capacity, and electricity generation data, as well as descriptive text. Chapter 2 presents current (through 1996) information on the US solar energy industry. A glossary of renewable energy terms is also included. 15 figs., 42 tabs.

  19. Solar Energetic Particles: Sampling Coronal Abundances

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.

    1998-05-01

    In the large solar energetic particle (SEP) events, coronal mass ejections (CMEs) drive shock waves out through the corona that accelerate elements of the ambient material to MeV energies in a fairly democratic, temperature-independent manner. These events provide the most complete source of information on element abundances in the corona. Relative abundances of 22 elements from H through Zn display the well-known dependence on the first ionization potential (FIP) that distinguishes coronal and photospheric material. For most elements, the main abundance variations depend upon the gyrofrequency, and hence on the charge-to-mass ratio, Q/A, of the ion. Abundance variations in the dominant species, H and He, are not Q/A dependent, presumably because of non-linear wave-particle interactions of H and He during acceleration. Impulsive flares provide a different sample of material that confirms the Ne:Mg:Si and He/C abundances in the corona.

  20. Effects of landscape anthropization on mosquito community composition and abundance

    NASA Astrophysics Data System (ADS)

    Ferraguti, Martina; Martínez-de La Puente, Josué; Roiz, David; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

    2016-07-01

    Anthropogenic landscape transformation has an important effect on vector-borne pathogen transmission. However, the effects of urbanization on mosquito communities are still only poorly known. Here, we evaluate how land-use characteristics are related to the abundance and community composition of mosquitoes in an area with endemic circulation of numerous mosquito-borne pathogens. We collected 340 829 female mosquitoes belonging to 13 species at 45 localities spatially grouped in 15 trios formed by 1 urban, 1 rural and 1 natural area. Mosquito abundance and species richness were greater in natural and rural areas than in urban areas. Environmental factors including land use, vegetation and hydrological characteristics were related to mosquito abundance and community composition. Given the differing competences of each species in pathogen transmission, these results provide valuable information on the transmission potential of mosquito-borne pathogens that will be of great use in public and animal health management by allowing, for instance, the identification of the priority areas for pathogen surveillance and vector control.

  1. Measurement scale in maximum entropy models of species abundance

    PubMed Central

    Frank, Steven A.

    2010-01-01

    The consistency of the species abundance distribution across diverse communities has attracted widespread attention. In this paper, I argue that the consistency of pattern arises because diverse ecological mechanisms share a common symmetry with regard to measurement scale. By symmetry, I mean that different ecological processes preserve the same measure of information and lose all other information in the aggregation of various perturbations. I frame these explanations of symmetry, measurement, and aggregation in terms of a recently developed extension to the theory of maximum entropy. I show that the natural measurement scale for the species abundance distribution is log-linear: the information in observations at small population sizes scales logarithmically and, as population size increases, the scaling of information grades from logarithmic to linear. Such log-linear scaling leads naturally to a gamma distribution for species abundance, which matches well with the observed patterns. Much of the variation between samples can be explained by the magnitude at which the measurement scale grades from logarithmic to linear. This measurement approach can be applied to the similar problem of allelic diversity in population genetics and to a wide variety of other patterns in biology. PMID:21265915

  2. Effects of landscape anthropization on mosquito community composition and abundance

    PubMed Central

    Ferraguti, Martina; Martínez-de la Puente, Josué; Roiz, David; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

    2016-01-01

    Anthropogenic landscape transformation has an important effect on vector-borne pathogen transmission. However, the effects of urbanization on mosquito communities are still only poorly known. Here, we evaluate how land-use characteristics are related to the abundance and community composition of mosquitoes in an area with endemic circulation of numerous mosquito-borne pathogens. We collected 340 829 female mosquitoes belonging to 13 species at 45 localities spatially grouped in 15 trios formed by 1 urban, 1 rural and 1 natural area. Mosquito abundance and species richness were greater in natural and rural areas than in urban areas. Environmental factors including land use, vegetation and hydrological characteristics were related to mosquito abundance and community composition. Given the differing competences of each species in pathogen transmission, these results provide valuable information on the transmission potential of mosquito-borne pathogens that will be of great use in public and animal health management by allowing, for instance, the identification of the priority areas for pathogen surveillance and vector control. PMID:27373794

  3. Effects of landscape anthropization on mosquito community composition and abundance.

    PubMed

    Ferraguti, Martina; Martínez-de la Puente, Josué; Roiz, David; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

    2016-01-01

    Anthropogenic landscape transformation has an important effect on vector-borne pathogen transmission. However, the effects of urbanization on mosquito communities are still only poorly known. Here, we evaluate how land-use characteristics are related to the abundance and community composition of mosquitoes in an area with endemic circulation of numerous mosquito-borne pathogens. We collected 340 829 female mosquitoes belonging to 13 species at 45 localities spatially grouped in 15 trios formed by 1 urban, 1 rural and 1 natural area. Mosquito abundance and species richness were greater in natural and rural areas than in urban areas. Environmental factors including land use, vegetation and hydrological characteristics were related to mosquito abundance and community composition. Given the differing competences of each species in pathogen transmission, these results provide valuable information on the transmission potential of mosquito-borne pathogens that will be of great use in public and animal health management by allowing, for instance, the identification of the priority areas for pathogen surveillance and vector control. PMID:27373794

  4. US Renewable Futures in the GCAM

    SciTech Connect

    Smith, Steven J.; Mizrahi, Andrew H.; Karas, Joseph F.; Nathan, Mayda

    2011-10-06

    This project examines renewable energy deployment in the United States using a version of the GCAM integrated assessment model with detailed a representation of renewables, the GCAM-RE. Electricity generation was modeled in four generation segments and 12-subregions. This level of regional and sectoral detail allows a more explicit representation of renewable energy generation. Wind, solar thermal power, and central solar PV plants are implemented in explicit resource classes with new intermittency parameterizations appropriate for each technology. A scenario analysis examines a range of assumptions for technology characteristics, climate policy, and long-distance transmission. We find that renewable generation levels grow over the century in all scenarios. As expected, renewable generation increases with lower renewable technology costs, more stringent climate policy, and if alternative low-carbon technology are not available. The availability of long distance transmission lowers policy costs and changes the renewable generation mix.

  5. Acceleration of Rural Industrialization Using Renewable Energy Technolgoy

    NASA Astrophysics Data System (ADS)

    Abdullah, Kamaruddin

    2007-10-01

    Solar, wind, biomass and micro-hydro can be found in abundant in almost all rural area throughout the world. Despite of the fact that there are already so many research results showing the potential application of these renewable resources to substitute fossil fuel and to increase added value of local products, however, up to now very view if any result that has been realized in significant way. A concept of Small Provessing Unit using renewable energy sources have been introduced in Indonesia since 1999, in which domestically developed conversion technology, such as the greenhouse effect (GHE) solar drying system has been applied to process agricultural products such as coffee, cocoa, soices, various types of fishes and sea weeds. In addition, hybrid nocturnal cooling method has also beeing developed and used to help the farmer in extending shelf life of tropical fruits and vegetables and therefore, contributed in reducing post harvest losses. The Small Processing Unit concept as well as the developed renewable energy technology are now gradually being appreciated by both the central and local authorities, the private sectors including the NGO. The demand of such system is also gradually increasing each year and the area of applications have been extended not only within the heavtily inhavited Java Island but also to the other island of Indonesia. Our experiences in dealing with the system have also been transferred to fellow ASEAN engineers as well as those coming from the African continent through training and workshops activities. The future direction of the development will be to enhace the role of the Small Processing Unit (SPU) by providing more value added facilities driven by renewable energy technology.

  6. Influence of Coronal Abundance Variations

    NASA Technical Reports Server (NTRS)

    Scargle, Jeffrey D. (Technical Monitor); Kashyap, Vinay

    2005-01-01

    The PI of this project was Jeff Scargle of NASA/Ames. Co-I's were Alma Connors of Eureka Scientific/Wellesley, and myself. Part of the work was subcontracted to Eureka Scientific via SAO, with Vinay Kashyap as PI. This project was originally assigned grant number NCC2-1206, and was later changed to NCC2-1350 for administrative reasons. The goal of the project was to obtain, derive, and develop statistical and data analysis tools that would be of use in the analyses of high-resolution, high-sensitivity data that are becoming available with new instruments. This is envisioned as a cross-disciplinary effort with a number of "collaborators" including some at SA0 (Aneta Siemiginowska, Peter Freeman) and at the Harvard Statistics department (David van Dyk, Rostislav Protassov, Xiao-li Meng, Epaminondas Sourlas, et al). We have developed a new tool to reliably measure the metallicities of thermal plasma. It is unfeasible to obtain high-resolution grating spectra for most stars, and one must make the best possible determination based on lower-resolution, CCD-type spectra. It has been noticed that most analyses of such spectra have resulted in measured metallicities that were significantly lower than when compared with analyses of high- resolution grating data where available (see, e.g., Brickhouse et al., 2000, ApJ 530,387). Such results have led to the proposal of the existence of so-called Metal Abundance Deficient, or "MAD" stars (e.g., Drake, J.J., 1996, Cool Stars 9, ASP Conf.Ser. 109, 203). We however find that much of these analyses may be systematically underestimating the metallicities, and using a newly developed method to correctly treat the low-counts regime at the high-energy tail of the stellar spectra (van Dyk et al. 2001, ApJ 548,224), have found that the metallicities of these stars are generally comparable to their photospheric values. The results were reported at the AAS (Sourlas, Yu, van Dyk, Kashyap, and Drake, 2000, BAAS 196, v32, #54.02), and at the

  7. Anaerobic codigestion of dairy manure and food manufacturing waste for renewable energy generation in New York State

    NASA Astrophysics Data System (ADS)

    Rankin, Matthew J.

    Anaerobic digestion is a microbiological process that converts biodegradable organic material into biogas, consisting primarily of methane and carbon dioxide. Anaerobic digestion technologies have been integrated into wastewater treatment facilities nationwide for many decades to increase the economic viability of the treatment process by converting a waste stream into two valuable products: biogas and fertilizer. Thus, anaerobic digestion offers potential economic and environmental benefits of organic waste diversion and renewable energy generation. The use of biogas has many applications, including cogeneration, direct combustion, upgrading for conversion to feed a fuel cell, and compression for injection into the natural gas grid or for vehicular use. The potential benefits of waste diversion and renewable energy generation are now being realized by major organic waste generators in New York State, in particular the food manufacturing and dairy industries, thus warranting an analysis of the energy generation potential for these waste products. Anaerobic codigestion of dairy manure and food-based feedstocks reflects a cradle-to- cradle approach to organic waste management. Given both of their abundance throughout New York State, waste-to-energy processes represent promising waste management strategies. The objective of this thesis was to evaluate the current technical and economic feasibility of anaerobically codigesting existing dairy manure and food manufacturing waste feedstocks in New York State to produce high quality biogas for renewable energy generation. The first element to determining the technical feasibility of anaerobic codigestion potential in New York State was to first understand the feedstock availability. A comprehensive survey of existing organic waste streams was conducted. The key objective was to identify the volume and composition of dairy manure and liquid-phase food manufacturing waste streams available in New York State to make

  8. Review of Big Bang Nucleosynthesis and Primordial Abundances

    NASA Astrophysics Data System (ADS)

    Tytler, David; O'Meara, John M.; Suzuki, Nao; Lubin, Dan

    2001-03-01

    the light nuclei, but unfortunately in most cases we are not yet seeing much improvement in the accuracy of the primordial abundances. Since we are now interested in the highest accuracy and reliability for all nuclei, the few objects with the most extensive observations give by far the most convincing results. Earlier measurements of 4He may have obtained too low a value because the He emission line strengths were reduced by undetected stellar absorption lines. The systematic errors associated with the 4He abundance have frequently been underestimated in the past, and this problem persists. When two groups use the same data and different ways to estimate the electron density and 4He abundance, the results differ by more than the quoted systematic errors. While the methods used by Izotov and Thuan [1] seem to be an advance on those used before, the other method is reasonable, and hence the systematic error should encompass the range in results. The abundance of 7Li is measured to high accuracy, but we do not know how much was produced prior to the formation of the stars, and how much was destroyed (depleted) in the stars. 6Li helps limit the amount of depletion of 7Li, but by an uncertain amount since it too has been depleted. BBN is successful because it uses known physics and measured cross-sections for the nuclear reactions. It gives accurate predictions for the abundances of five light nuclei as a function of the one free parameter η. The other initial conditions seem natural: the universe began homogeneous and hotter than T > 1011 K (30 Mev). The predicted abundances agree with most observations, and the required η is consistent with other, less accurate, measurements of the baryon density. Abundance measurements of the baryon density, from the CMB, clusters of galaxies and the Lyα forest, will give η. Although the accuracy might not exceed that obtained from D/H, this is an important advance because BBN then gives abundance predictions with no adjustable

  9. The Mass Flux of Non-renewable Energy for Humanity

    NASA Astrophysics Data System (ADS)

    Solomon, Edwin

    The global energy supply relies on non-renewable energy sources, coal, crude oil, and natural gas, along with nuclear power from uranium and these finite resources are located within the upper few kilometers of the Earth's crust. The total quantity of non-renewable energy resources consumed relative to the total quantity available is an essential question facing humanity. Analyses of energy consumption was conducted for the period 1800--2014 using data from the U. S. Energy Information Administration (EIA) and World Energy Production, 1800--1985 to determine the balance between non-renewable energy resources consumed and ultimately recoverable reserves. Annual energy consumption was plotted for each non-renewable resource followed by analyses to determine annual growth rates of consumption. Results indicated total energy consumption grew approximately exponentially 3.6% per year from 1800--1975 and was linear from 1975--2014. The ultimately recoverable reserves (URR) plus the total quantity consumed to date equals the total energy resource reserve prior to exploitation (7.15 x 1018 grams). Knowing the original resource quantity and the annual consumption and growth rates, we can forecast the duration of remaining resources using different scenarios. Alternatively, we can use population growth models and consumption trends to determine the per capita allocation trends and model that into the future. Alternative modeling of future resource allocation on a per capita bases suggests that resource lifetime may be significantly less than that predicted from consumption and production dynamics alone.

  10. RP-5 Renewable Energy Efficiency Project

    SciTech Connect

    Neil Clifton; Eliza Jane Whitman; Jamal A. Zughbi

    2003-07-28

    This is the fourth quarterly technical report for the RP-5 Renewable Energy Efficiency Project. The report summarizes the work progress, effort and activities that took place during the period of April 1, 2003 to June 30, 2003. However, IEUA is preparing a Supplemental report that will be mailed to the Department of Energy (DOE) by August 1, 2003, that provides additional information regarding IEUA's plan to expedite certain project activities. The report has been prepared in accordance with the Department of Energy (DOE) Guidelines. This technical report covers all meetings, discussions, and engineering and design activities that took place to finalize the project scope of work and complete the Request for Proposal (RFP) for the RP-5 Renewable Energy Efficiency Project. IEUA has decided to invite three more consulting engineering firms besides CH2M Hill, the Public Interest Energy Research (PIER) Consultant, to submit proposals for the design of the energy efficiency project. The proposals are currently in the evaluation phase and a decision is expected by the end of July. IEUA moved to its new headquarters building on June 13, 2003. The central plant is the system that supplies cooling and heating water to the headquarters building, and it primarily consists of equipment listed in the cooperative agreement under ''Chiller and Heater''. The central plant equipment was successfully installed and started. Other activities include gas analysis of three sources of low quality digester gas and foul air which could be used as fuel for an innovative flex microturbine. IEUA is also working with Stirling Energy Systems to determine if the Agency should be a host site for their equipment for testing the engine's operation on digester and natural gas. A matching funds update is also included in the Results and Discussion section, which presents the work effort performed by the PIER Consultant and the associated costs that serve as matching funds for the RP-5 Project during

  11. Beyond Renewable Portfolio Standards: An Assessment of Regional Supply and Demand Conditions Affecting the Future of Renewable Energy in the West; Report and Executive Summary

    SciTech Connect

    Hurlbut, D. J.; McLaren, J.; Gelman, R.

    2013-08-01

    This study assesses the outlook for utility-scale renewable energy development in the West once states have met their renewable portfolio standard (RPS) requirements. In the West, the last state RPS culminates in 2025, so the analysis uses 2025 as a transition point on the timeline of RE development. Most western states appear to be on track to meet their final requirements, relying primarily on renewable resources located relatively close to the customers being served. What happens next depends on several factors including trends in the supply and price of natural gas, greenhouse gas and other environmental regulations, consumer preferences, technological breakthroughs, and future public policies and regulations. Changes in any one of these factors could make future renewable energy options more or less attractive.

  12. The biogeography of abundant and rare bacterioplankton in the lakes and reservoirs of China.

    PubMed

    Liu, Lemian; Yang, Jun; Yu, Zheng; Wilkinson, David M

    2015-09-01

    Bacteria play key roles in the ecology of both aquatic and terrestrial ecosystems; however, little is known about their diversity and biogeography, especially in the rare microbial biosphere of inland freshwater ecosystems. Here we investigated aspects of the community ecology and geographical distribution of abundant and rare bacterioplankton using high-throughput sequencing and examined the relative influence of local environmental variables and regional (spatial) factors on their geographical distribution patterns in 42 lakes and reservoirs across China. Our results showed that the geographical patterns of abundant and rare bacterial subcommunities were generally similar, and both of them showed a significant distance-decay relationship. This suggests that the rare bacterial biosphere is not a random assembly, as some authors have assumed, and that its distribution is most likely subject to the same ecological processes that control abundant taxa. However, we identified some differences between the abundant and rare groups as both groups of bacteria showed a significant positive relationship between sites occupancy and abundance, but the abundant bacteria exhibited a weaker distance-decay relationship than the rare bacteria. Our results implied that rare subcommunities were mostly governed by local environmental variables, whereas the abundant subcommunities were mainly affected by regional factors. In addition, both local and regional variables that were significantly related to the spatial variation of abundant bacterial community composition were different to those of rare ones, suggesting that abundant and rare bacteria may have discrepant ecological niches and may play different roles in natural ecosystems. PMID:25748371

  13. The role of geography and host abundance in the distribution of parasitoids of an alien pest

    PubMed Central

    Nováková, Petra; Holuša, Jaroslav

    2016-01-01

    Chalcid wasps (Hymenoptera: Chalcidoidea) are probably the most effective and abundant parasitoids of the horse chestnut leaf miner (Cameraria ohridella), an alien pest in Europe that lacks specialized enemies. We studied how the species richness and abundance of chalcids are influenced by altitude, direction of an alien spread and host abundance of C. ohridella. We quantified the numbers and species richness of chalcid wasps and the numbers of C. ohridella that emerged from horse chestnut (Aesculus hippocastanum) leaf litter samples collected from 35 sites in the Czech Republic. Species richness of chalcids, which was considered an indicator of the possible adaptation of parasitoids to this alien host, was unrelated to C. ohridella abundance, direction of spread, or altitude. Chalcid abundance, which was considered an indicator of parasitism of the alien host, was strongly and positively related to C. ohridella abundance. Chalcid abundance was negatively related to direction of spread and positively related, although in a non-linear manner, to altitude. The relationship of chalcid abundance with direction of spread and altitude was weaker than that with C. ohridella abundance. The results provide evidence that biological control of the alien pest C. ohridella by natural enemies might develop in the future. PMID:26819849

  14. The role of geography and host abundance in the distribution of parasitoids of an alien pest.

    PubMed

    Nováková, Petra; Holuša, Jaroslav; Horák, Jakub

    2016-01-01

    Chalcid wasps (Hymenoptera: Chalcidoidea) are probably the most effective and abundant parasitoids of the horse chestnut leaf miner (Cameraria ohridella), an alien pest in Europe that lacks specialized enemies. We studied how the species richness and abundance of chalcids are influenced by altitude, direction of an alien spread and host abundance of C. ohridella. We quantified the numbers and species richness of chalcid wasps and the numbers of C. ohridella that emerged from horse chestnut (Aesculus hippocastanum) leaf litter samples collected from 35 sites in the Czech Republic. Species richness of chalcids, which was considered an indicator of the possible adaptation of parasitoids to this alien host, was unrelated to C. ohridella abundance, direction of spread, or altitude. Chalcid abundance, which was considered an indicator of parasitism of the alien host, was strongly and positively related to C. ohridella abundance. Chalcid abundance was negatively related to direction of spread and positively related, although in a non-linear manner, to altitude. The relationship of chalcid abundance with direction of spread and altitude was weaker than that with C. ohridella abundance. The results provide evidence that biological control of the alien pest C. ohridella by natural enemies might develop in the future. PMID:26819849

  15. Silicon abundances in population I giants

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika

    1992-01-01

    Silicon to carbon abundance ratios for population I giants were determined from emission lines originating in the transition layers between stellar chromospheres and coronae. For effective temperatures larger than 6200 K we find a group of stars with increased silicon to carbon but normal nitrogen to carbon abundance ratios. These stars are presumably descendents from Ap stars with increased surface silicon to carbon abundance ratios. For G stars this anomaly disappears as is to be expected due to the increased depth of the convection zone and therefore deeper mixing which dilutes the surface overabundances. The disappearance of the abundance anomalies proves that the anomalous abundances observed for the F giants are indeed only a surface phenomenon. It also proves that the same holds for their progenitors, the Ap and Am stars, as has been generally believed. Unexplained is the increased silicon to carbon abundance ratio observed for several stars cooler than 5100 L. RS CVn and related stars do not show this increased abundance ratio. There are also some giants which appear to be enriched in carbon, perhaps due to a helium flash with some mixing if the star is a clump star.

  16. Monitoring Butterfly Abundance: Beyond Pollard Walks

    PubMed Central

    Pellet, Jérôme; Bried, Jason T.; Parietti, David; Gander, Antoine; Heer, Patrick O.; Cherix, Daniel; Arlettaz, Raphaël

    2012-01-01

    Most butterfly monitoring protocols rely on counts along transects (Pollard walks) to generate species abundance indices and track population trends. It is still too often ignored that a population count results from two processes: the biological process (true abundance) and the statistical process (our ability to properly quantify abundance). Because individual detectability tends to vary in space (e.g., among sites) and time (e.g., among years), it remains unclear whether index counts truly reflect population sizes and trends. This study compares capture-mark-recapture (absolute abundance) and count-index (relative abundance) monitoring methods in three species (Maculinea nausithous and Iolana iolas: Lycaenidae; Minois dryas: Satyridae) in contrasted habitat types. We demonstrate that intraspecific variability in individual detectability under standard monitoring conditions is probably the rule rather than the exception, which questions the reliability of count-based indices to estimate and compare specific population abundance. Our results suggest that the accuracy of count-based methods depends heavily on the ecology and behavior of the target species, as well as on the type of habitat in which surveys take place. Monitoring programs designed to assess the abundance and trends in butterfly populations should incorporate a measure of detectability. We discuss the relative advantages and inconveniences of current monitoring methods and analytical approaches with respect to the characteristics of the species under scrutiny and resources availability. PMID:22859980

  17. Phylogenetic structure and host abundance drive disease pressure in communities.

    PubMed

    Parker, Ingrid M; Saunders, Megan; Bontrager, Megan; Weitz, Andrew P; Hendricks, Rebecca; Magarey, Roger; Suiter, Karl; Gilbert, Gregory S

    2015-04-23

    Pathogens play an important part in shaping the structure and dynamics of natural communities, because species are not affected by them equally. A shared goal of ecology and epidemiology is to predict when a species is most vulnerable to disease. A leading hypothesis asserts that the impact of disease should increase with host abundance, producing a 'rare-species advantage'. However, the impact of a pathogen may be decoupled from host abundance, because most pathogens infect more than one species, leading to pathogen spillover onto closely related species. Here we show that the phylogenetic and ecological structure of the surrounding community can be important predictors of disease pressure. We found that the amount of tissue lost to disease increased with the relative abundance of a species across a grassland plant community, and that this rare-species advantage had an additional phylogenetic component: disease pressure was stronger on species with many close relatives. We used a global model of pathogen sharing as a function of relatedness between hosts, which provided a robust predictor of relative disease pressure at the local scale. In our grassland, the total amount of disease was most accurately explained not by the abundance of the focal host alone, but by the abundance of all species in the community weighted by their phylogenetic distance to the host. Furthermore, the model strongly predicted observed disease pressure for 44 novel host species we introduced experimentally to our study site, providing evidence for a mechanism to explain why phylogenetically rare species are more likely to become invasive when introduced. Our results demonstrate how the phylogenetic and ecological structure of communities can have a key role in disease dynamics, with implications for the maintenance of biodiversity, biotic resistance against introduced weeds, and the success of managed plants in agriculture and forestry. PMID:25903634

  18. Predicting the dynamics of protein abundance.

    PubMed

    Mehdi, Ahmed M; Patrick, Ralph; Bailey, Timothy L; Bodén, Mikael

    2014-05-01

    Protein synthesis is finely regulated across all organisms, from bacteria to humans, and its integrity underpins many important processes. Emerging evidence suggests that the dynamic range of protein abundance is greater than that observed at the transcript level. Technological breakthroughs now mean that sequencing-based measurement of mRNA levels is routine, but protocols for measuring protein abundance remain both complex and expensive. This paper introduces a Bayesian network that integrates transcriptomic and proteomic data to predict protein abundance and to model the effects of its determinants. We aim to use this model to follow a molecular response over time, from condition-specific data, in order to understand adaptation during processes such as the cell cycle. With microarray data now available for many conditions, the general utility of a protein abundance predictor is broad. Whereas most quantitative proteomics studies have focused on higher organisms, we developed a predictive model of protein abundance for both Saccharomyces cerevisiae and Schizosaccharomyces pombe to explore the latitude at the protein level. Our predictor primarily relies on mRNA level, mRNA-protein interaction, mRNA folding energy and half-life, and tRNA adaptation. The combination of key features, allowing for the low certainty and uneven coverage of experimental observations, gives comparatively minor but robust prediction accuracy. The model substantially improved the analysis of protein regulation during the cell cycle: predicted protein abundance identified twice as many cell-cycle-associated proteins as experimental mRNA levels. Predicted protein abundance was more dynamic than observed mRNA expression, agreeing with experimental protein abundance from a human cell line. We illustrate how the same model can be used to predict the folding energy of mRNA when protein abundance is available, lending credence to the emerging view that mRNA folding affects translation efficiency

  19. Predicting the Dynamics of Protein Abundance

    PubMed Central

    Mehdi, Ahmed M.; Patrick, Ralph; Bailey, Timothy L.; Bodén, Mikael

    2014-01-01

    Protein synthesis is finely regulated across all organisms, from bacteria to humans, and its integrity underpins many important processes. Emerging evidence suggests that the dynamic range of protein abundance is greater than that observed at the transcript level. Technological breakthroughs now mean that sequencing-based measurement of mRNA levels is routine, but protocols for measuring protein abundance remain both complex and expensive. This paper introduces a Bayesian network that integrates transcriptomic and proteomic data to predict protein abundance and to model the effects of its determinants. We aim to use this model to follow a molecular response over time, from condition-specific data, in order to understand adaptation during processes such as the cell cycle. With microarray data now available for many conditions, the general utility of a protein abundance predictor is broad. Whereas most quantitative proteomics studies have focused on higher organisms, we developed a predictive model of protein abundance for both Saccharomyces cerevisiae and Schizosaccharomyces pombe to explore the latitude at the protein level. Our predictor primarily relies on mRNA level, mRNA–protein interaction, mRNA folding energy and half-life, and tRNA adaptation. The combination of key features, allowing for the low certainty and uneven coverage of experimental observations, gives comparatively minor but robust prediction accuracy. The model substantially improved the analysis of protein regulation during the cell cycle: predicted protein abundance identified twice as many cell-cycle-associated proteins as experimental mRNA levels. Predicted protein abundance was more dynamic than observed mRNA expression, agreeing with experimental protein abundance from a human cell line. We illustrate how the same model can be used to predict the folding energy of mRNA when protein abundance is available, lending credence to the emerging view that mRNA folding affects translation

  20. The Palm Desert Renewable Hydrogen Transportation System

    SciTech Connect

    Lehman, P.

    1996-10-01

    The present paper describes, for purposes of the Department of Energy (DoE) Hydrogen Program Review, Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period January through June 1996. This period represents the first six months of the three year project. The estimated cost over three years is $3.9M, $1.859M of which is funded by the DoE ($600 k for fiscal year 1996). The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project will demonstrate the practical utility of hydrogen as a transportation fuel and proton exchange membrane (PEM) fuel cells as vehicle power plants. This transportation system will be developed in the City of Palm Desert in southern California and will include a fleet of 8 fuel cell powered vehicles, solar and wind powered hydrogen generating facilities, a consumer-ready refueling station, and a service infrastructure. The system holds the promise of a clean environment and an energy supply that is predictable, domestic, safe, and abundant. During, the first part of 1996 SERC has nearly completed building a fuel cell powered personal utility vehicle, which features an upgraded safety and computer system; they have designed and built a test bench that is able to mimic golf cart loads and test fuel cell system auxiliary components; they have begun the design of the solar hydrogen generating station; they have worked with Sandia National Laboratory on an advanced metal hydride storage system; they have increased the power density of the SERC fuel cell by as much as 50%; and they have reached out to the rest of the world with a new fact sheet, world wide web pages, a press release, video footage for a television program. and instruction within the community.

  1. Solar abundances and 3D model atmospheres

    NASA Astrophysics Data System (ADS)

    Ludwig, Hans-Günter; Caffau, Elisabetta; Steffen, Matthias; Bonifacio, Piercarlo; Freytag, Bernd; Cayrel, Roger

    2010-03-01

    We present solar photospheric abundances for 12 elements from optical and near-infrared spectroscopy. The abundance analysis was conducted employing 3D hydrodynamical (CO5BOLD) as well as standard 1D hydrostatic model atmospheres. We compare our results to others with emphasis on discrepancies and still lingering problems, in particular exemplified by the pivotal abundance of oxygen. We argue that the thermal structure of the lower solar photosphere is very well represented by our 3D model. We obtain an excellent match of the observed center-to-limb variation of the line-blanketed continuum intensity, also at wavelengths shortward of the Balmer jump.

  2. Interstellar Abundances Toward X Per, Revisited

    NASA Technical Reports Server (NTRS)

    Valencic, Lynne A.; Smith, Randall K.

    2012-01-01

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of O, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ACIS-S and XMM-Newton's RGS instruments. In general, we find that the abundances and their ratios are similar to those of young F and G stars and the most recent solar values. We compare our results with abundances required by dust grain models.

  3. Interstellar Abundances Toward X Per, Revisited

    NASA Technical Reports Server (NTRS)

    Valencic, Lynne A.; Smith, Randall K.

    2014-01-01

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of 0, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ ACIS-S and XMM-Newton's RGS instruments. In general, we find that the abundances and their ratios are similar to those of young F and G stars and the most recent solar values. We compare our results with abundances required by dust grain models.

  4. Abundance variations in solar energetic particles

    NASA Technical Reports Server (NTRS)

    Cane, H. V.; Reames, D. V.; Von Rosenvinge, T. T.

    1991-01-01

    Abundance variations are examined in a large number of events including smaller nonimpulsive events not previously considered. Whereas a comparison at equal energy per nucleon is appropriate for heavy ions this is not the case when including H. The best representation is either in terms of rigidity or energy per charge depending on the type of event under consideration. For the majority of large events, where particles are primarily accelerated at interplanetary shocks, if abundances relative to H are evaluated at equal energy per charge then abundance ratios are compatible with solar wind values and spectral shapes agree. Furthermore the behavior of H is then compatible with that of other high FIP elements.

  5. Renewable Energy Resources in Lebanon

    NASA Astrophysics Data System (ADS)

    Hamdy, R.

    2010-12-01

    The energy sector in Lebanon plays an important role in the overall development of the country, especially that it suffers from many serious problems. The fact that Lebanon is among the few countries that are not endowed with fossil fuels in the Middle East made this sector cause one third of the national debt in Lebanon. Despite the large government investments in the power sector, demand still exceeds supply and Lebanon frequently goes through black out in peak demand times or has to resort to importing electricity from Syria. The Energy production sector has dramatic environmental and economical impacts in the form of emitted gasses and environment sabotage, accordingly, it is imperative that renewable energy (RE) be looked at as an alternative energy source. Officials at the Ministry of Energy and Water (MEW) and Lebanese Electricity (EDL) have repeatedly expressed their support to renewable energy utilization. So far, only very few renewable energy applications can be observed over the country. Major efforts are still needed to overcome this situation and promote the use of renewable energy. These efforts are the shared responsibility of the government, EDL, NGO's and educational and research centers. Additionally, some efforts are being made by some international organizations such as UNDP, ESCWA, EC and other donor agencies operating in Lebanon. This work reviews the status of Energy in Lebanon, the installed RE projects, and the potential projects. It also reviews the stakeholders in the field of RE in Lebanon Conclusion In considering the best R.E. alternative, it is important to consider all potential R.E. sources, their costs, market availability, suitability for the selected location, significance of the energy produced and return on investment. Several RE resources in Lebanon have been investigated; Tides and waves energy is limited and not suitable two tentative sites for geothermal energy are available but not used. Biomass resources badly affect the

  6. Renewable-reagent electrochemical sensor

    DOEpatents

    Wang, Joseph; Olsen, Khris B.

    1999-01-01

    A new electrochemical probe(s) design allowing for continuous (renewable) reagent delivery. The probe comprises an integrated membrane-sampling/electrochemical sensor that prevents interferences from surface-active materials and greatly extends the linear range. The probe(s) is useful for remote or laboratory-based monitoring in connection with microdialysis sampling and electrochemical measurements of metals and organic compounds that are not readily detected in the absence of reacting with the compound. Also disclosed is a method of using the probe(s).

  7. Renewable-reagent electrochemical sensor

    DOEpatents

    Wang, J.; Olsen, K.B.

    1999-08-24

    A new electrochemical probe(s) design allowing for continuous (renewable) reagent delivery is described. The probe comprises an integrated membrane sampling/electrochemical sensor that prevents interferences from surface-active materials and greatly extends the linear range. The probe(s) is useful for remote or laboratory-based monitoring in connection with microdialysis sampling and electrochemical measurements of metals and organic compounds that are not readily detected in the absence of reacting with the compound. Also disclosed is a method of using the probe(s). 19 figs.

  8. Microsite abundance and distribution of woody seedlings in a South Carolina cypress-tupelo swamp

    SciTech Connect

    Huenneke, L.F.; Sharitz, R.R.

    1986-05-01

    At least 16 types of microsites or substrates for vascular plant seedlings can be distinguished in bald cypress-water tupelo (Taxodium distichum-Nyssa aquatica) swamps. We measured the relative abundances of these microsite types, and the distribution of woody seedlings on them, in two riverine swamp forests on the Savannah River floodplain, South Carolina. Microsite abundances in a little disturbed forest differed significantly from those in a more open stand which had experienced much recent sediment deposition from upstream erosion, as well as higher water temperatures. Woody seedlings were distributed nonrandomly among microsite types (i.e., not in proportion to the abundance of a given microsite type). There were significant differences in microsite distribution patterns among growth forms (tree spp. vs. shrubs vs. vines) and among species within growth form. Many human activities may alter substrate nature and abundance in a wetland, thus indirectly altering the abundance and species composition of seedling recruitment.

  9. Exergetic life cycle assessment of hydrogen production from renewables

    NASA Astrophysics Data System (ADS)

    Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

    Life cycle assessment is extended to exergetic life cycle assessment and used to evaluate the exergy efficiency, economic effectiveness and environmental impact of producing hydrogen using wind and solar energy in place of fossil fuels. The product hydrogen is considered a fuel for fuel cell vehicles and a substitute for gasoline. Fossil fuel technologies for producing hydrogen from natural gas and gasoline from crude oil are contrasted with options using renewable energy. Exergy efficiencies and greenhouse gas and air pollution emissions are evaluated for all process steps, including crude oil and natural gas pipeline transportation, crude oil distillation and natural gas reforming, wind and solar electricity generation, hydrogen production through water electrolysis, and gasoline and hydrogen distribution and utilization. The use of wind power to produce hydrogen via electrolysis, and its application in a fuel cell vehicle, exhibits the lowest fossil and mineral resource consumption rate. However, the economic attractiveness, as measured by a "capital investment effectiveness factor," of renewable technologies depends significantly on the ratio of costs for hydrogen and natural gas. At the present cost ratio of about 2 (per unit of lower heating value or exergy), capital investments are about five times lower to produce hydrogen via natural gas rather than wind energy. As a consequence, the cost of wind- and solar-based electricity and hydrogen is substantially higher than that of natural gas. The implementation of a hydrogen fuel cell instead of an internal combustion engine permits, theoretically, an increase in a vehicle's engine efficiency of about of two times. Depending on the ratio in engine efficiencies, the substitution of gasoline with "renewable" hydrogen leads to (a) greenhouse gas (GHG) emissions reductions of 12-23 times for hydrogen from wind and 5-8 times for hydrogen from solar energy, and (b) air pollution (AP) emissions reductions of 38

  10. The solar system abundance of tin

    NASA Astrophysics Data System (ADS)

    Loss, R. D.; Rosman, K. K. R.; de Laeter, J. R.

    1989-04-01

    The elemental abundance of tin has been determined by the mass spectrometric isotope dilution technique for four carbonaceous chondrites, including the Cl chondrites Orgueil and Ivuna. A solar system abundance of 3.98 (normalized to Si = 10 to the 6th atoms) can be derived from these data, which is in excellent agreement with the presently accepted value. Recently, a theoretical value of 2.82 + or - 0.21 (Si = 10 to the 6th atoms) has been proposed for the abundance of tin based on an s-process nucleosynthesis model. This value is 26 percent lower than the presently accepted solar system abundance. The present data confirm the higher value for tin and indicate that a reexamination of the assumptions on which the nucleosynthetic value is based is required.

  11. Coronal abundances determined from energetic particles

    NASA Technical Reports Server (NTRS)

    Reames, D. V.

    1995-01-01

    Solar energetic particles (SEPs) provide a measurement of coronal element abundances that is highly independent of the ionization states and temperature of the ions in the source plasma. The most complete measurements come from large 'gradual' events where ambient coronal plasma is swept up by the expanding shock wave from a coronal mass ejection. Particles from 'impulsive' flares have a pattern of acceleration-induced enhancements superimposed on the coronal abundances. Particles accelerated from high-speed solar wind streams at corotating shocks show a different abundance pattern corresponding to material from coronal holes. Large variations in He/O in coronal material are seen for both gradual and impulsive-flare events but other abundance ratios, such as Mg/Ne, are remarkably constant. SEP measurements now include hundreds of events spanning 15 years of high-quality measurement.

  12. SAGA: Stellar Abundances for Galatic Archeology

    NASA Astrophysics Data System (ADS)

    Suda, T.

    A tutorial for the Stellar Abundances for Galactic Archaeology (SAGA) database is presented. This paper describes the outline of the database, reports the current status of the data compilation and known problems, and presents plans for future updates and extensions.

  13. GALA: Stellar atmospheric parameters and chemical abundances

    NASA Astrophysics Data System (ADS)

    Mucciarelli, A.; Pancino, E.; Lovisi, L.; Ferraro, F. R.; Lapenna, E.

    2013-02-01

    GALA is a freely distributed Fortran code to derive the atmospheric parameters (temperature, gravity, microturbulent velocity and overall metallicity) and abundances for individual species of stellar spectra using the classical method based on the equivalent widths of metallic lines. The abundances of individual spectral lines are derived by using the WIDTH9 code developed by R. L. Kurucz. GALA is designed to obtain the best model atmosphere, by optimizing temperature, surface gravity, microturbulent velocity and metallicity, after rejecting the discrepant lines. Finally, it computes accurate internal errors for each atmospheric parameter and abundance. The code obtains chemical abundances and atmospheric parameters for large stellar samples quickly, thus making GALA an useful tool in the epoch of the multi-object spectrographs and large surveys.

  14. The abundant elements in interstellar dust

    NASA Technical Reports Server (NTRS)

    Sofia, Ulysses J.; Cardelli, Jason A.; Savage, Blair D.

    1994-01-01

    We explore the incorporation of the cosmically abundant species O, C, N, Mg, Si, Fe, and S into interstellar dust. Column densities based on Goddard High Resolution Spectrograph 3.5 km/s resolution measurements from the literature for eight individual absorbing regions toward five lines of sight are used. Corrections are applied as needed in order to account for recent improvements in oscillator strengths. In order to acquire the most accurate column densities, and check on the accuracy of the oscillator strengths, we compare column densities based on the very strong Lorentzian damped lines of C II, O I, N I, and Mg II with results for the weak lines of these species, and confirm the previously determined f-values for O I lambda 1335, C II lambda 2325, and N I lambda lambda 1159, 1160. New empirical f-values of 1.25 x 10(exp -3) and 6.25 x 10(exp -4), respectively, are derived for the Mg II weak doublet at 1239 and 1240 A. Assuming a cosmic reference abundance based on solar and B star values, we derive depletions and dust-phase abundances which suggest that more than 70% of the available Mg and Fe is incorporated into dust-grain cores, whereas only 35% of the silicon is. This implies that oxides are important constituents of the grain core population. Mg and Fe atoms are mantled onto grain cores in a ratio of 1.8 to 1, whereas approximately 4.0 Si atoms are in the mantle per Fe atom. Since Si is not expected to accrete onto silicate or graphite grains, other grain cores, perhaps oxides and/or metallic Fe, may provide mantling sites for this species. The abundances of Fe and Mg in mantles would imply that graphite grains must have a substantial coating unless oxides provide significant mantling sites for these species. The abundance of O and N in the dust phase as implied by the solar reference abundance values are difficult to reconcile with the fact that these elements are not expected to participate in mantle formation, and the 3.1 micrometer H2O ice feature is

  15. Rapid detection of microbial cell abundance in aquatic systems.

    PubMed

    Rocha, Andrea M; Yuan, Quan; Close, Dan M; O'Dell, Kaela B; Fortney, Julian L; Wu, Jayne; Hazen, Terry C

    2016-11-15

    The detection and quantification of naturally occurring microbial cellular densities is an essential component of environmental systems monitoring. While there are a number of commonly utilized approaches for monitoring microbial abundance, capacitance-based biosensors represent a promising approach because of their low-cost and label-free detection of microbial cells, but are not as well characterized as more traditional methods. Here, we investigate the applicability of enhanced alternating current electrokinetics (ACEK) capacitive sensing as a new application for rapidly detecting and quantifying microbial cellular densities in cultured and environmentally sourced aquatic samples. ACEK capacitive sensor performance was evaluated using two distinct and dynamic systems - the Great Australian Bight and groundwater from the Oak Ridge Reservation in Oak Ridge, TN. Results demonstrate that ACEK capacitance-based sensing can accurately determine microbial cell counts throughout cellular concentrations typically encountered in naturally occurring microbial communities (10(3)-10(6) cells/mL). A linear relationship was observed between cellular density and capacitance change correlations, allowing a simple linear curve fitting equation to be used for determining microbial abundances in unknown samples. This work provides a foundation for understanding the limits of capacitance-based sensing in natural environmental samples and supports future efforts focusing on evaluating the robustness ACEK capacitance-based within aquatic environments. PMID:27315516

  16. Elemental abundance determinations for meteors by spectroscopy.

    NASA Technical Reports Server (NTRS)

    Harvey, G. A.

    1973-01-01

    Relative elemental abundance determinations for meteors by spectroscopy are discussed. Relative abundances of spectroscopically accessible elements of four major shower meteors and one sporadic meteor are presented. A sporadic meteor with dominant sodium radiation and an iron-deficient sporadic meteor are analyzed. Empirical and theoretical tests for self-absorption in optical meteor plasmas have been conducted. Both ionization and incomplete dissociation are found to severely deplete certain neutral atoms from meteor plasmas.

  17. Coronae of Stars with Supersolar Elemental Abundances

    NASA Technical Reports Server (NTRS)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-01-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, iota Hor, HR 7291, tau Boo, and alpha Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and tau Boo no FIP effect is present, while iota Hor, HR 7291, and alpha Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  18. Coronae of stars with supersolar elemental abundances

    NASA Astrophysics Data System (ADS)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-05-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, ι Hor, HR 7291, τ Boo, and α Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and τ Boo no FIP effect is present, while ι Hor, HR 7291, and α Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  19. Engineering microbial chemical factories to produce renewable “biomonomers”

    PubMed Central

    Adkins, Jake; Pugh, Shawn; McKenna, Rebekah; Nielsen, David R.

    2012-01-01

    By applying metabolic engineering tools and strategies to engineer synthetic enzyme pathways, the number and diversity of commodity and specialty chemicals that can be derived directly from renewable feedstocks is rapidly and continually expanding. This of course includes a number of monomer building-block chemicals that can be used to produce replacements to many conventional plastic materials. This review aims to highlight numerous recent and important advancements in the microbial production of these so-called “biomonomers.” Relative to naturally-occurring renewable bioplastics, biomonomers offer several important advantages, including improved control over the final polymer structure and purity, the ability to synthesize non-natural copolymers, and allowing products to be excreted from cells which ultimately streamlines downstream recovery and purification. To highlight these features, a handful of biomonomers have been selected as illustrative examples of recent works, including polyamide monomers, styrenic vinyls, hydroxyacids, and diols. Where appropriate, examples of their industrial penetration to date and end-product uses are also highlighted. Novel biomonomers such as these are ultimately paving the way toward new classes of renewable bioplastics that possess a broader diversity of properties than ever before possible. PMID:22969753

  20. Dentin Biomodification: Strategies, Renewable Resources and Clinical Applications

    PubMed Central

    Bedran-Russo, Ana K.; Pauli, Guido F.; Chen, Shao-Nong; McAlpine, James; Castellan, Carina S.; Phansalkar, Rasika S; Aguiar, Thaiane R.; Vidal, Cristina M.P.; Napotilano, José; Nam, Joo-Won; Leme, Ariene A.

    2014-01-01

    Objectives The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications. Methods The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications. In addition, new data is presented on laboratorial methods for the standardization of proanthocyanidin-rich preparations as a renewable source of plant-derived biomodification agents. Results Biomodification agents can be categorized as physical methods and chemical agents. Synthetic and naturally occurring chemical strategies present distinctive mechanism of interaction with the tissue. Initially thought to be driven only by inter- or intra-molecular collagen induced non-enzymatic collagen cross-linking, multiple interactions with other dentin components are fundamental for the long-term biomechanics and biostability of the tissue. Oligomeric proanthocyanidins show promising bioactivity, and their chemical complexity requires systematic evaluation of the active compounds to produce a fully standardized intervention material from renewable resource, prior to their detailed clinical evaluation. Significance Understanding the hierarchical structure of dentin and the targeting effect of the bioactive compounds will establish their use in both dentin-biomaterials interface and caries management. PMID:24309436