WorldWideScience

Sample records for primary oxidation product

  1. Primary oxidation and reduction products in x-irradiated aspartic acid

    International Nuclear Information System (INIS)

    Adams, S.M.; Budzinski, E.E.; Box, H.C.

    1976-01-01

    The primary reduction products identified by ESR--ENDOR spectroscopy in single crystals of DL-aspartic acid hydrochloride irradiated at 4.2degreeK are anions formed by addition of an electron to the carbonyl oxygen atoms of the carboxylic acid groups. The main consequence of the oxidation process is to produce a hole centered mainly on atomic chlorine

  2. Primary productivity

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Parulekar, A.H.

    Photosynthetic production in the oceans in relation to light, nutrients and mixing processes is discussed. Primary productivity in the estuarine region is reported to be high in comparison to coastal and oceanic waters. Upwelling phenomenon...

  3. Chemistry and liquid chromatography methods for the analyses of primary oxidation products of triacylglycerols.

    Science.gov (United States)

    Zeb, A

    2015-05-01

    Triacylglycerols (TAGs) are one of the major components of the cells in higher biological systems, which can act as an energy reservoir in the living cells. The unsaturated fatty acid moiety is the key site of oxidation and formation of oxidation compounds. The TAG free radical generates several primary oxidation compounds. These include hydroperoxides, hydroxides, epidioxides, hydroperoxy epidioxides, hydroxyl epidioxides, and epoxides. The presence of these oxidized TAGs in the cell increases the chances of several detrimental processes. For this purpose, several liquid chromatography (LC) methods were reported in their analyses. This review is therefore focused on the chemistry, oxidation, extraction, and the LC methods reported in the analyses of oxidized TAGs. The studies on thin-layer chromatography were mostly focused on the total oxidized TAGs separation and employ hexane as major solvent. High-performance LC (HPLC) methods were discussed in details along with their merits and demerits. It was found that most of the HPLC methods employed isocratic elution with methanol and acetonitrile as major solvents with an ultraviolet detector. The coupling of HPLC with mass spectrometry (MS) highly increases the efficiency of analysis as well as enables reliable structural elucidation. The use of MS was found to be helpful in studying the oxidation chemistry of TAGs and needs to be extended to the complex biological systems.

  4. Production and release of acylcarnitines by primary myotubes reflect the differences in fasting fat oxidation of the donors.

    Science.gov (United States)

    Wolf, Magnus; Chen, Shili; Zhao, Xinjie; Scheler, Mika; Irmler, Martin; Staiger, Harald; Beckers, Johannes; de Angelis, Martin Hrabé; Fritsche, Andreas; Häring, Hans-Ulrich; Schleicher, Erwin D; Xu, Guowang; Lehmann, Rainer; Weigert, Cora

    2013-06-01

    Acylcarnitines are biomarkers of incomplete β-oxidation and mitochondrial lipid overload but indicate also high rates of mitochondrial fatty acid oxidation. It is unknown whether the production of acylcarnitines in primary human myotubes obtained from lean, metabolically healthy subjects reflects the fat oxidation in vivo. Our objective was to quantify the acylcarnitine production in myotubes obtained from subjects with low and high fasting respiratory quotient (RQ). Fasting RQ was determined by indirect calorimetry. Muscle biopsies from the vastus lateralis muscle were taken from 6 subjects with low fasting RQ (mean 0.79 ± 0.03) and 6 with high fasting RQ (0.90 ± 0.03), and satellite cells were isolated, cultured, and differentiated to myotubes. Myotubes were cultivated with 125 μM (13)C-labeled palmitate for 30 minutes and 4 and 24 hours. Quantitative profiling of 42 intracellular and 31 extracellular acylcarnitines was performed by stable isotope dilution-based metabolomics analysis by liquid chromatography coupled to mass spectrometry. Myotubes from donors with high fasting RQ produced and released significant higher amounts of medium-chain acylcarnitines. High (13)C8 and (13)C10 acylcarnitine levels in the extracellular compartment correlated with high fasting RQ. The decreased expression of medium-chain acyl-coenzyme A dehydrogenase (MCAD) in these myotubes can explain the higher rate of incomplete fatty acid oxidation. A lower intracellular [(13)C]acetylcarnitine to carnitine and lower intracellular (13)C16/(13)C18 acylcarnitine to carnitine ratio indicate reduced fatty acid oxidation capacity in these myotubes. Mitochondrial DNA content was not different. Acylcarnitine production and release from primary human myotubes of donors with high fasting RQ indicate a reduced fatty acid oxidation capacity and a higher rate of incomplete fatty acid oxidation. Thus, quantitative profiling of acylcarnitine production in human myotubes can be a suitable tool to

  5. Primary atmospheric oxidation mechanism for toluene.

    Science.gov (United States)

    Baltaretu, Cristian O; Lichtman, Eben I; Hadler, Amelia B; Elrod, Matthew J

    2009-01-08

    The products of the primary OH-initiated oxidation of toluene were investigated using the turbulent flow chemical ionization mass spectrometry technique at temperatures ranging from 228 to 298 K. A major dienedial-producing pathway was detected for the first time for toluene oxidation, and glyoxal and methylglyoxal were found to be minor primary oxidation products. The results suggest that secondary oxidation processes involving dienedial and epoxide primary products are likely responsible for previous observations of glyoxal and methylglyoxal products from toluene oxidation. Because the dienedial-producing pathway is a null cycle for tropospheric ozone production and glyoxal and methylglyoxal are important secondary organic aerosol precursors, these new findings have important implications for the modeling of toluene oxidation in the atmosphere.

  6. Thiol dioxygenase turnover yields benzothiazole products from 2-mercaptoaniline and O2-dependent oxidation of primary alcohols.

    Science.gov (United States)

    Morrow, William P; Sardar, Sinjinee; Thapa, Pawan; Hossain, Mohammad S; Foss, Frank W; Pierce, Brad S

    2017-10-01

    Thiol dioxygenases are non-heme mononuclear iron enzymes that catalyze the O 2 -dependent oxidation of free thiols (-SH) to produce the corresponding sulfinic acid (-SO 2 - ). Previous chemical rescue studies identified a putative Fe III -O 2 - intermediate that precedes substrate oxidation in Mus musculus cysteine dioxygenase (Mm CDO). Given that a similar reactive intermediate has been identified in the extradiol dioxygenase 2, 3-HCPD, it is conceivable that these enzymes share other mechanistic features with regard to substrate oxidation. To explore this possibility, enzymatic reactions with Mm CDO (as well as the bacterial 3-mercaptopropionic acid dioxygenase, Av MDO) were performed using a substrate analogue (2-mercaptoaniline, 2ma). This aromatic thiol closely approximates the catecholic substrate of homoprotocatechuate of 2, 3-HPCD while maintaining the 2-carbon thiol-amine separation preferred by Mm CDO. Remarkably, both enzymes exhibit 2ma-gated O 2 -consumption; however, none of the expected products for thiol dioxygenase or intra/extradiol dioxygenase reactions were observed. Instead, benzothiazoles are produced by the condensation of 2ma with aldehydes formed by an off-pathway oxidation of primary alcohols added to aqueous reactions to solubilize the substrate. The observed oxidation of 1º-alcohols in 2ma-reactions is consistent with the formation of a high-valent intermediate similar to what has been reported for cytochrome P450 and mononuclear iron model complexes. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Nitrification is a primary driver of nitrous oxide production in laboratory microcosms from different land-use soils

    Directory of Open Access Journals (Sweden)

    Rui Liu

    2016-09-01

    Full Text Available Most studies on soil N2O emissions have focused either on the quantifying of agricultural N2O fluxes or on the effect of environmental factors on N2O emissions. However very limited information is available on how land-use will affect N2O production, and nitrifiers involved in N2O emissions in agricultural soil ecosystems. Therefore, this study aimed at evaluating the relative importance of nitrification and denitrification to N2O emissions from different land-use soils and identifying the potential underlying microbial mechanisms. A 15N-tracing experiment was conducted under controlled laboratory conditions on four agricultural soils collected from different land-use. We measured N2O fluxes, nitrate (NO3− and ammonium (NH4+ concentration and15N2O, 15NO3− and 15NH4+ enrichment during the incubation. Quantitative PCR was used to quantify ammonia-oxidizing archaea (AOA and ammonia-oxidizing bacteria (AOB. Our results showed that nitrification was the main contributor to N2O production in soils from sugarcane, dairy pasture and cereal cropping systems, while denitrification played a major role in N2O production in the vegetable soil under the experimental conditions. Nitrification contributed to 96.7% of the N2O emissions in sugarcane soil followed by 71.3% in the cereal cropping soil and 70.9% in the dairy pasture soil, while only around 20.0% of N2O was produced from nitrification in vegetable soil. The proportion of nitrified nitrogen as N2O (PN2O value varied across different soils, with the highest PN2O value (0.26‰ found in the cereal cropping soil, which was around 10 times higher than that in other three systems. AOA were the abundant ammonia oxidizers, and were significantly correlated to N2O emitted from nitrification in the sugarcane soil, while AOB were significantly correlated with N2O emitted from nitrification in the cereal cropping soil. Our findings suggested that soil type and land-use might have strongly affected the

  8. Nitrification Is a Primary Driver of Nitrous Oxide Production in Laboratory Microcosms from Different Land-Use Soils.

    Science.gov (United States)

    Liu, Rui; Hu, Hangwei; Suter, Helen; Hayden, Helen L; He, Jizheng; Mele, Pauline; Chen, Deli

    2016-01-01

    Most studies on soil N2O emissions have focused either on the quantifying of agricultural N2O fluxes or on the effect of environmental factors on N2O emissions. However, very limited information is available on how land-use will affect N2O production, and nitrifiers involved in N2O emissions in agricultural soil ecosystems. Therefore, this study aimed at evaluating the relative importance of nitrification and denitrification to N2O emissions from different land-use soils and identifying the potential underlying microbial mechanisms. A (15)N-tracing experiment was conducted under controlled laboratory conditions on four agricultural soils collected from different land-use. We measured N2O fluxes, nitrate ([Formula: see text]), and ammonium ([Formula: see text]) concentration and (15)N2O, (15)[Formula: see text], and (15)[Formula: see text] enrichment during the incubation. Quantitative PCR was used to quantify ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). Our results showed that nitrification was the main contributor to N2O production in soils from sugarcane, dairy pasture and cereal cropping systems, while denitrification played a major role in N2O production in the vegetable soil under the experimental conditions. Nitrification contributed to 96.7% of the N2O emissions in sugarcane soil followed by 71.3% in the cereal cropping soil and 70.9% in the dairy pasture soil, while only around 20.0% of N2O was produced from nitrification in vegetable soil. The proportion of nitrified nitrogen as N2O (PN2O-value) varied across different soils, with the highest PN2O-value (0.26‰) found in the cereal cropping soil, which was around 10 times higher than that in other three systems. AOA were the abundant ammonia oxidizers, and were significantly correlated to N2O emitted from nitrification in the sugarcane soil, while AOB were significantly correlated with N2O emitted from nitrification in the cereal cropping soil. Our findings suggested that soil

  9. Method for the production of primary amines

    NARCIS (Netherlands)

    Baldenius, Kai-Uwe; Ditrich, Klaus; Breurer, Michael; Navickas, Vaidotas; Janssen, Dick; Crismaru, Ciprian; Bartsch, Sebastian

    2014-01-01

    The present invention relates to a novel enzymatically catalyzed method for the production of aliphatic primary amines, which method comprises the enzymatic oxidation of a primary aliphatic alcohol catalyzed by an alcohol dehydrogenase, amination of the resulting oxocompound catalyzed by a

  10. Chemoselective organocatalytic aerobic oxidation of primary amines to secondary imines.

    Science.gov (United States)

    Wendlandt, Alison E; Stahl, Shannon S

    2012-06-01

    Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched benzylic amines relative to secondary/tertiary amines, branched benzylic amines, and aliphatic amines. The exquisite selectivity for benzylic amines enables oxidative self-sorting within dynamic mixtures of amines and imines to afford high yields of cross-coupled imine products.

  11. Contribution of crenarchaeal autotrophic ammonia oxidizers to the dark primary production in Tyrrhenian deep waters (Central Mediterranean Sea).

    Science.gov (United States)

    Yakimov, Michail M; Cono, Violetta La; Smedile, Francesco; DeLuca, Thomas H; Juárez, Silvia; Ciordia, Sergio; Fernández, Marisol; Albar, Juan Pablo; Ferrer, Manuel; Golyshin, Peter N; Giuliano, Laura

    2011-06-01

    Mesophilic Crenarchaeota have recently been thought to be significant contributors to nitrogen (N) and carbon (C) cycling. In this study, we examined the vertical distribution of ammonia-oxidizing Crenarchaeota at offshore site in Southern Tyrrhenian Sea. The median value of the crenachaeal cell to amoA gene ratio was close to one suggesting that virtually all deep-sea Crenarchaeota possess the capacity to oxidize ammonia. Crenarchaea-specific genes, nirK and ureC, for nitrite reductase and urease were identified and their affiliation demonstrated the presence of 'deep-sea' clades distinct from 'shallow' representatives. Measured deep-sea dark CO(2) fixation estimates were comparable to the median value of photosynthetic biomass production calculated for this area of Tyrrhenian Sea, pointing to the significance of this process in the C cycle of aphotic marine ecosystems. To elucidate the pivotal organisms in this process, we targeted known marine crenarchaeal autotrophy-related genes, coding for acetyl-CoA carboxylase (accA) and 4-hydroxybutyryl-CoA dehydratase (4-hbd). As in case of nirK and ureC, these genes are grouped with deep-sea sequences being distantly related to those retrieved from the epipelagic zone. To pair the molecular data with specific functional attributes we performed [(14)C]HCO(3) incorporation experiments followed by analyses of radiolabeled proteins using shotgun proteomics approach. More than 100 oligopeptides were attributed to 40 marine crenarchaeal-specific proteins that are involved in 10 different metabolic processes, including autotrophy. Obtained results provided a clear proof of chemolithoautotrophic physiology of bathypelagic crenarchaeota and indicated that this numerically predominant group of microorganisms facilitate a hitherto unrecognized sink for inorganic C of a global importance.

  12. Oxidative stress in primary glomerular diseases

    DEFF Research Database (Denmark)

    Markan, Suchita; Kohli, Harbir Singh; Sud, Kamal

    2008-01-01

    To evaluate the status of oxidative stress in patients with different primary glomerular diseases (PGD) which have differential predisposition to renal failure.......To evaluate the status of oxidative stress in patients with different primary glomerular diseases (PGD) which have differential predisposition to renal failure....

  13. Contribution of crenarchaeal autotrophic ammonia oxidizers to the dark primary production in Tyrrhenian deep waters (Central Mediterranean Sea)

    OpenAIRE

    Yakimov, Michail M.; La Cono, Violetta; Smedile, Francesco; DeLuca, Thomas H.; Juarez, Silvia; Ciordia, Sergio; Fernandez, Marisol; Albar, Juan Pablo; Ferrer, Manuel; Golyshin, Peter N.; Giuliano, Laura

    2011-01-01

    Mesophilic Crenarchaeota have recently been thought to be significant contributors to nitrogen (N) and carbon (C) cycling. In this study, we examined the vertical distribution of ammonia-oxidizing Crenarchaeota at offshore site in Southern Tyrrhenian Sea. The median value of the crenachaeal cell to amoA gene ratio was close to one suggesting that virtually all deep-sea Crenarchaeota possess the capacity to oxidize ammonia. Crenarchaea-specific genes, nirK and ureC, for nitrite reductase and u...

  14. Differential intracellular calcium influx, nitric oxide production, ICAM-1 and IL8 expression in primary bovine endothelial cells exposed to nonesterified fatty acids.

    Science.gov (United States)

    Loaiza, Anitsi; Carretta, María D; Taubert, Anja; Hermosilla, Carlos; Hidalgo, María A; Burgos, Rafael A

    2016-02-25

    Nonesterified fatty acids (NEFAs) are involved in proinflammatory processes in cattle, including in the increased expression of adhesion molecules in endothelial cells. However, the mechanisms underlying these effects are still unknown. The aim of this study was to assess the effects of NEFAs on the intracellular calcium (Ca(2+) i) influx, nitric oxide production, and ICAM-1 and IL-8 expression in primary bovine umbilical vein endothelial cells (BUVECs). Myristic (MA), palmitic (PA), stearic (SA), oleic (OA) and linoleic acid (LA) rapidly increased Ca(2+) i. The calcium response to all tested NEFAs showed an extracellular calcium dependence and only the LA response was significantly inhibited until the intracellular calcium was chelated. The EC50 values for MA and LA were 125 μM and 37 μM, respectively, and the MA and LA effects were dependent on calcium release from the endoplasmic reticulum stores and on the L-type calcium channels. Only the calcium response to MA was significantly reduced by GW1100, a selective G-protein-coupled free fatty acid receptor (GPR40) antagonist. We also detected a functional FFAR1/GPR40 protein in BUVECs by using western blotting and the FFAR1/GPR40 agonist TAK-875. Only LA increased the cellular nitric oxide levels in a calcium-dependent manner. LA stimulation but not MA stimulation increased ICAM-1 and IL-8-expression in BUVECs. This effect was inhibited by GW1100, an antagonist of FFAR1/GPR40, but not by U-73122, a phospholipase C inhibitor. These findings strongly suggest that each individual NEFA stimulates endothelial cells in a different way, with clearly different effects on intracellular calcium mobilization, NO production, and IL-8 and ICAM-1 expression in primary BUVECs. These findings not only extend our understanding of NEFA-mediated diseases in ruminants, but also provide new insight into the different molecular mechanisms involved during endothelial cell activation by NEFAs.

  15. Primary Productivity (PP_Master)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included primary production for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came...

  16. HANPP Collection: Human Appropriation of Net Primary Productivity as a Percentage of Net Primary Productivity

    Data.gov (United States)

    National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) as a Percentage of Net Primary Product (NPP) portion of the HANPP Collection represents a map identifying...

  17. Transparent conducting oxides and production thereof

    Science.gov (United States)

    Gessert, Timothy A.; Yoshida, Yuki; Coutts, Timothy J.

    2014-06-10

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber. The method may also comprise depositing a metal oxide on the target in the process chamber to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  18. Primary and secondary oxidative stress in Bacillus

    NARCIS (Netherlands)

    Mols, Maarten; Abee, Tjakko

    Coping with oxidative stress originating from oxidizing compounds or reactive oxygen species (ROS), associated with the exposure to agents that cause environmental stresses, is one of the prerequisites for an aerobic lifestyle of Bacillus spp. such as B. subtilis, B. cereus and B. anthracis. This

  19. Primary and secondary oxidative stress in Bacillus

    NARCIS (Netherlands)

    Mols, J.M.; Abee, T.

    2011-01-01

    Coping with oxidative stress originating from oxidizing compounds or reactive oxygen species (ROS), associated with the exposure to agents that cause environmental stresses, is one of the prerequisites for an aerobic lifestyle of Bacillus spp. such as B. subtilis, B. cereus and B. anthracis. This

  20. Deep primary production in coastal pelagic systems

    DEFF Research Database (Denmark)

    Lyngsgaard, Maren Moltke; Richardson, Katherine; Markager, Stiig

    2014-01-01

    produced. The primary production (PP) occurring below the surface layer, i.e. in the pycnocline-bottom layer (PBL), is shown to contribute significantly to total PP. Oxygen concentrations in the PBL are shown to correlate significantly with the deep primary production (DPP) as well as with salinity...... that eutrophication effects may include changes in the structure of planktonic food webs and element cycling in the water column, both brought about through an altered vertical distribution of PP....

  1. Primary production of tropical marine ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.

    Among tropical marine ecosystems estuaries are one of the highly productive areas and act as a nursery to large number of organisms. The primary production in most of the estuaries is less during the monsoon period. Post-monsoon period shows...

  2. Nitrous Oxide Production by Abundant Benthic Macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    of the short-term metabolic induction of gut denitrification is the preferential production of nitrous oxide rather than dinitrogen. On a large scale, gut denitrification in, for instance, Chironomus plumosus larvae can increase the overall nitrous oxide emission of lake sediment by a factor of eight. We...... screened more than 20 macrofauna species for nitrous oxide production and identified filter-feeders and deposit-feeders that occur ubiquitously and at high abundance (e.g., chironomids, ephemeropterans, snails, and mussels) as the most important emitters of nitrous oxide. In contrast, predatory species...... that do not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. Ephemera danica, a very abundant mayfly larva, was monitored monthly in a nitrate-polluted stream. Nitrous oxide production by this filter-feeder was highly dependent on nitrate availability...

  3. Primary Productivity of the Cengklik Dam Boyolali

    Directory of Open Access Journals (Sweden)

    WIRYANTO

    2002-01-01

    Full Text Available Primary productivity dynamic of the water ecosystem was conducted faster in the last decades. This study was intended to find out the primary productivity of Cengklik dam Boyolali, Central Java to explain the ecosystem dynamic and to lead the maintenance of dam. This study used quantitative methods in completely randomized group design (CRD, and the data was analized by Analysis of Variance (ANAVA. Samples were taken horizontally in four sampling point, respectively in the riparian zone, around of the floating net (“karamba”, in the center of dam water and around of the ex-paddy fields. There were taken vertically in three-depth point in each of the sampling point, respectively 0.5 meter, 1.5 meter, and 2.5 meter. The results showed that the gross primary productivity of the dam was 11.122.500-22.545.600 mgC/m3/days, and the primary productivity differences in each of the point sampling caused by light intensity, nutrient supply, and abundance of the chlorophyll organisms.

  4. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-01-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. The efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness, and as a monitor of system corrosion effects. The discussion is based mostly on the results and observations from Ontario Hydro plants, and their comparisons with PWRs. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of lay-up and various start-up conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on corrosion-product transport on the primary side of steam generators are also discussed. (author)

  5. Oxide production program monthly report - December 2014

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, Evelyn A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Whitworth, Julia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lloyd, Jane Alexandria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hampton, David Earl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Benavidez, Amelia A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-15

    A summary of the major activities, accomplishments, milestones, financial summary, project performance and issues facing the ARIES Oxide Production Program for the month of December 2014 is presented in this Executive Summary.

  6. Primary productivity of the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.; Devassy, V.P.

    The average surface and column primary productivity, chl a and particulate organic carbon, estimated at 24 stations during Feb. 1979, were respectively 5.3 mg C/m3/d and 273 mg C/m2 /d; 0.03 mg/m3 and 3.64 mg/m2; and 132mg/m3 and 4.59 g/m2...

  7. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-10-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. Efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness and as a monitor of system corrosion effects. The discussion is based mostly on the results of observations from Ontario Hydro plants, and their comparisons with pressurized-water reactors. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of layup and various startup conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on CPT on the primary side of SGs are also discussed. (author)

  8. Recent advances in Phytosterol Oxidation Products.

    Science.gov (United States)

    O'Callaghan, Yvonne; McCarthy, Florence O; O'Brien, Nora M

    2014-04-11

    Phytosterols and their oxidation products have become increasingly investigated in recent years with respect to their roles in diet and nutrition. We present a comprehensive review of recent literature on Phytosterol Oxidation Products (POP) identifying critical areas for future investigation. It is evident that POP are formed on food storage/preparation; are absorbed and found in human serum; do not directly affect cholesterol absorption; have evidence of atherogenicity and inflammation; have distinct levels of cytotoxicity; are implicated with high levels of oxidative stress, glutathione depletion, mitochondrial dysfunction and elevated caspase activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Kinetics and mechanism of oxidation of aliphatic primary alcohols by ...

    Indian Academy of Sciences (India)

    Unknown

    Kinetics and mechanism of oxidation of aliphatic primary alcohols by quinolinium bromochromate. SONU SARASWAT, VINITA SHARMA and K K BANERJI*. Department of Chemistry, JNV University, Jodhpur 342 005, India e-mail: banerjikk@rediffmail.com. MS received 4 December 2001; revised 2 November 2002.

  10. Metal-Free Oxidation of Primary Amines to Nitriles through Coupled Catalytic Cycles.

    Science.gov (United States)

    Lambert, Kyle M; Bobbitt, James M; Eldirany, Sherif A; Kissane, Liam E; Sheridan, Rose K; Stempel, Zachary D; Sternberg, Francis H; Bailey, William F

    2016-04-04

    Synergism among several intertwined catalytic cycles allows for selective, room temperature oxidation of primary amines to the corresponding nitriles in 85-98% isolated yield. This metal-free, scalable, operationally simple method employs a catalytic quantity of 4-acetamido-TEMPO (ACT; TEMPO=2,2,6,6-tetramethylpiperidine N-oxide) radical and the inexpensive, environmentally benign triple salt oxone as the terminal oxidant under mild conditions. Simple filtration of the reaction mixture through silica gel affords pure nitrile products. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Nitroxyl-mediated oxidation of lignin and polycarboxylated products

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Shannon S.; Rafiee, Mohammad

    2018-02-27

    Methods of selectively modifying lignin, polycarboxylated products thereof, and methods of deriving aromatic compounds therefrom. The methods comprise electrochemically oxidizing lignin using stable nitroxyl radicals to selectively oxidize primary hydroxyls on .beta.-O-4 phenylpropanoid units to corresponding carboxylic acids while leaving the secondary hydroxyls unchanged. The oxidation results in polycarboxylated lignin in the form of a polymeric .beta.-hydroxy acid. The polymeric .beta.-hydroxy acid has a high loading of carboxylic acid and can be isolated in acid form, deprotonated, and/or converted to a salt. The .beta.-hydroxy acid, anion, or salt can also be subjected to acidolysis to generate various aromatic monomers or oligomers. The initial oxidation of lignin to the polycarboxylated form renders the lignin more susceptible to acidolysis and thereby enhances the yield of aromatic monomers and oligomers obtained through acidolysis.

  12. Cathode recovery products of oxidation of oils

    Directory of Open Access Journals (Sweden)

    М.М. Захарчук

    2009-01-01

    Full Text Available  The article provides the review of electrochemical reduction of carbonic compounds – those that are among main oxidation of oils  hydrocarbons products. The principal possibility of ketons to alcohols  reduction is proved in practice based on the experimental data . The methodical algoritm of quantative control of the catod reduction is developed, which uses the reduction-oxidizing potentiometric titration method.

  13. Mass extinctions: Ecological selectivity and primary production

    Science.gov (United States)

    Rhodes, Melissa Clark; Thayer, Charles W.

    1991-09-01

    If mass extinctions were caused by reduced primary productivity, then extinctions should be concentrated among animals with starvation-susceptible feeding modes, active lifestyles, and high-energy budgets. The stratigraphic ranges (by stage) of 424 genera of bivalves and 309 genera of articulate brachiopods suggest that there was an unusual reduction of primary productivity at the Cretaceous/Tertiary (K/T) boundary extinction. For bivalves at the K/T, there were (1) selective extinction of suspension feeders and other susceptible trophic categories relative to deposit feeders and other resistant categories, and (2) among suspension feed-ers, selective extinction of bivalves with active locomotion. During the Permian-Triassic (P/Tr) extinction and Jurassic background time, extinction rates among suspension feeders were greater for articulate brachiopods than for bivalves. But during the K/T event, extinction rates of articulates and suspension-feeding bivalves equalized, possibly because the low-energy budgets of articulates gave them an advantage when food was scarce.

  14. Multiple stressors for oceanic primary production

    KAUST Repository

    Agusti, Susana

    2015-12-15

    Marine ecosystems are increasingly exposed to stress factors of anthropogenic origin that change their function, structure and services they deliver society. Climate change occurs simultaneously with other changes in the environment acting jointly in a context of global environmental change. For oceanic phytoplankton communities, the research conducted so far has identified stress factors associated with global change and their impact individually (warming, acidification, increased UVB radiation, pollutants). But when several stressors act simultaneously interactions and responses are not equal to the sum of individual impacts, but may have synergistic effects (the effects are multiplied) or antagonistic (cancel out the effects) that hinder predictions of the vulnerability of ecosystems to global change. Here we will examine the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change. The trend for autotrophic picoplankton to increase with temperature in the ocean has led to predictions that autotrophic picoplankton abundance will increase with warming. However, it is documented a trend towards a decline in productivity, due to declined autotroph biomass and production with warming and the associated stratification in the subtropical ocean. Models predicting an increase in abundance are in contradiction with the reported decrease in productivity in several oceanic areas, and associate oligotrophication. Here we perform a global study to analyze the relationships of autotrophic picoplankton with oceanic temperature, nutrients, underwater light and ultraviolet B (UVB) radiation, and productivity. We built a model to project the future changes of autotrophic picoplankton considering multiple environmental changes in future climate scenarios for the subtropical gyres. We considered increased water temperature, and associated changes in productivity and underwater light and UVB. The model show that warming and

  15. Multiple stressors for oceanic primary production

    KAUST Repository

    Agusti, Susana; Llabré s, Moira; Lubiá n, Luis M.; Moreno-Ostos, Enrique; Estrada, Marta; Duarte, Carlos M.; Cerezo, Maria I.

    2015-01-01

    Marine ecosystems are increasingly exposed to stress factors of anthropogenic origin that change their function, structure and services they deliver society. Climate change occurs simultaneously with other changes in the environment acting jointly in a context of global environmental change. For oceanic phytoplankton communities, the research conducted so far has identified stress factors associated with global change and their impact individually (warming, acidification, increased UVB radiation, pollutants). But when several stressors act simultaneously interactions and responses are not equal to the sum of individual impacts, but may have synergistic effects (the effects are multiplied) or antagonistic (cancel out the effects) that hinder predictions of the vulnerability of ecosystems to global change. Here we will examine the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change. The trend for autotrophic picoplankton to increase with temperature in the ocean has led to predictions that autotrophic picoplankton abundance will increase with warming. However, it is documented a trend towards a decline in productivity, due to declined autotroph biomass and production with warming and the associated stratification in the subtropical ocean. Models predicting an increase in abundance are in contradiction with the reported decrease in productivity in several oceanic areas, and associate oligotrophication. Here we perform a global study to analyze the relationships of autotrophic picoplankton with oceanic temperature, nutrients, underwater light and ultraviolet B (UVB) radiation, and productivity. We built a model to project the future changes of autotrophic picoplankton considering multiple environmental changes in future climate scenarios for the subtropical gyres. We considered increased water temperature, and associated changes in productivity and underwater light and UVB. The model show that warming and

  16. Hydrogen sulfide oxidation without oxygen - oxidation products and pathways

    International Nuclear Information System (INIS)

    Fossing, H.

    1992-01-01

    Hydrogen sulfide oxidation was studied in anoxic marine sediments-both in undisturbed sediment cores and in sediment slurries. The turn over of hydrogen sulfide was followed using 35 S-radiolabeled hydrogen sulfide which was injected into the sediment. However, isotope exchange reactions between the reduced sulfur compounds, in particular between elemental sulfur and hydrogen sulfide, influenced on the specific radioactivity of these pools. It was, therefore, not possible to measure the turn over rates of the reduced sulfur pools by the radiotracer technique but merely to use the radioisotope to demonstrate some of the oxidation products. Thiosulfate was one important intermediate in the anoxic oxidation of hydrogen sulfide and was continuously turned over by reduction, oxidation and disproportionation. The author discusses the importance of isotope exchange and also presents the results from experiments in which both 35 S-radiolabeled elemental sulfur, radiolabeled hydrogen sulfide and radiolabeled thiosulfate were used to study the intermediates in the oxidative pathways of the sulfur cycle

  17. Production of oceanic nitrous oxide by ammonia-oxidizing archaea

    Directory of Open Access Journals (Sweden)

    C. R. Löscher

    2012-07-01

    Full Text Available The recent finding that microbial ammonia oxidation in the ocean is performed by archaea to a greater extent than by bacteria has drastically changed the view on oceanic nitrification. The numerical dominance of archaeal ammonia-oxidizers (AOA over their bacterial counterparts (AOB in large parts of the ocean leads to the hypothesis that AOA rather than AOB could be the key organisms for the oceanic production of the strong greenhouse gas nitrous oxide (N2O that occurs as a by-product of nitrification. Very recently, enrichment cultures of marine ammonia-oxidizing archaea have been reported to produce N2O.

    Here, we demonstrate that archaeal ammonia monooxygenase genes (amoA were detectable throughout the water column of the eastern tropical North Atlantic (ETNA and eastern tropical South Pacific (ETSP Oceans. Particularly in the ETNA, comparable patterns of abundance and expression of archaeal amoA genes and N2O co-occurred in the oxygen minimum, whereas the abundances of bacterial amoA genes were negligible. Moreover, selective inhibition of archaea in seawater incubations from the ETNA decreased the N2O production significantly. In studies with the only cultivated marine archaeal ammonia-oxidizer Nitrosopumilus maritimus SCM1, we provide the first direct evidence for N2O production in a pure culture of AOA, excluding the involvement of other microorganisms as possibly present in enrichments. N. maritimus showed high N2O production rates under low oxygen concentrations comparable to concentrations existing in the oxycline of the ETNA, whereas the N2O production from two AOB cultures was comparably low under similar conditions. Based on our findings, we hypothesize that the production of N2O in tropical ocean areas results mainly from archaeal nitrification and will be affected by the predicted decrease in dissolved

  18. Primary production in the Bay of Bengal during August 1977

    Digital Repository Service at National Institute of Oceanography (India)

    Devassy, V.P.; Bhattathiri, P.M.A.; Radhakrishna, K.

    Primary production, chlorophyll @ia@@, phaeophytin, phytoplankton and particulate organic carbon (POC) were studied at 14 stations in the Bay of Bengal during August 1977. Column primary production, chlorophyll @ia@@, and phaeopigments varied from 0...

  19. Relationship between chlorophyll-a and column primary production

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.; Bhargava, R.M.S.

    Relationship between surface chlorophyll a and column primary production has been established to help in estimating the latter more quickly and accurately. The equation derived is Primary Production, y = 0.54 Ln Chl a - 0.6. The relationship...

  20. HANPP Collection: Global Patterns in Net Primary Productivity (NPP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Net Primary Productivity (NPP) portion of the Human Appropriation of Net Primary Productivity (HANPP) Collection maps the net amount of solar...

  1. Corrosion products in the primary circuits of PWRs

    International Nuclear Information System (INIS)

    Darras, R.

    1983-01-01

    The characteristics of PWR primary circuits are recalled, particularly the chemical specifications of the medium and the various materials used (austenitic steel, nickel alloys, cobalt-based alloys and zirconium alloys). The behaviour of these materials as regards general corrosion in nominal and transient conditions is then outlined briefly, special emphasis being laid on the effect of the determining parameters on the quantity of corrosion products formed. The release of the latter into the primary coolant is caused by two main processes: solubilization and erosion. Particular attention was given therefore to the laws governing the solubility of the oxides involved, especially as a function of temperature and pH. Erosion, or release in the form of solid particles, is relatively severe during transient events. As these corrosion products are then carried through all circuits, they cause deposits to form in favourable places on the walls as a result either of precipitation of soluble species or of sedimentation followed by consolidation of suspended particles. The presence of corrosion products in the primary circuits creates a particular impact since they become radioactive as they pass through the core and especially when they remain in it in the form of deposits; as a result, the products are capable of contaminating the entire system. Finally, although long-term reliability is obviously an essential condition for materials developed, attention must also be given to problems associated with a build-up of corrosion products in the cooling circuits and efforts made to minimize them. To that end, a number of precautions are recommended, and various remedies can be applied: selecting materials which are not readily activated, keeping structures clean, purifying fluids properly, restricting solubilization and precipitation, and perhaps, periodic decontamination. (author)

  2. Production of superconducting ceramic oxides by coprecipitation

    International Nuclear Information System (INIS)

    Bizaio, L.R.; Lima, M.A.F. de; Figueiredo Jardim, R.de; Pinheiro, E.A.; Galembeck, F.

    1988-01-01

    An alternative method for production of ceramic oxides is described. The method consist in the coprecipitation reaction of metallic ions with oxalic acid. The obtainment samples present additional phases characterized by X-rays and optical microscopy. (C.G.C.) [pt

  3. Graphene oxide and H2 production from bioelectrochemical graphite oxidation.

    Science.gov (United States)

    Lu, Lu; Zeng, Cuiping; Wang, Luda; Yin, Xiaobo; Jin, Song; Lu, Anhuai; Jason Ren, Zhiyong

    2015-11-17

    Graphene oxide (GO) is an emerging material for energy and environmental applications, but it has been primarily produced using chemical processes involving high energy consumption and hazardous chemicals. In this study, we reported a new bioelectrochemical method to produce GO from graphite under ambient conditions without chemical amendments, value-added organic compounds and high rate H2 were also produced. Compared with abiotic electrochemical electrolysis control, the microbial assisted graphite oxidation produced high rate of graphite oxide and graphene oxide (BEGO) sheets, CO2, and current at lower applied voltage. The resultant electrons are transferred to a biocathode, where H2 and organic compounds are produced by microbial reduction of protons and CO2, respectively, a process known as microbial electrosynthesis (MES). Pseudomonas is the dominant population on the anode, while abundant anaerobic solvent-producing bacteria Clostridium carboxidivorans is likely responsible for electrosynthesis on the cathode. Oxygen production through water electrolysis was not detected on the anode due to the presence of facultative and aerobic bacteria as O2 sinkers. This new method provides a sustainable route for producing graphene materials and renewable H2 at low cost, and it may stimulate a new area of research in MES.

  4. Global patterns in human consumption of net primary production

    Science.gov (United States)

    Imhoff, Marc L.; Bounoua, Lahouari; Ricketts, Taylor; Loucks, Colby; Harriss, Robert; Lawrence, William T.

    2004-06-01

    The human population and its consumption profoundly affect the Earth's ecosystems. A particularly compelling measure of humanity's cumulative impact is the fraction of the planet's net primary production that we appropriate for our own use. Net primary production-the net amount of solar energy converted to plant organic matter through photosynthesis-can be measured in units of elemental carbon and represents the primary food energy source for the world's ecosystems. Human appropriation of net primary production, apart from leaving less for other species to use, alters the composition of the atmosphere, levels of biodiversity, energy flows within food webs and the provision of important ecosystem services. Here we present a global map showing the amount of net primary production required by humans and compare it to the total amount generated on the landscape. We then derive a spatial balance sheet of net primary production `supply' and `demand' for the world. We show that human appropriation of net primary production varies spatially from almost zero to many times the local primary production. These analyses reveal the uneven footprint of human consumption and related environmental impacts, indicate the degree to which human populations depend on net primary production `imports' and suggest policy options for slowing future growth of human appropriation of net primary production.

  5. Valuing ecosystem services. A shadow price for net primary production

    International Nuclear Information System (INIS)

    Richmond, Amy; Kaufmann, Robert K.; Myneni, Ranga B.

    2007-01-01

    We analyze the contribution of ecosystem services to GDP and use this contribution to calculate an empirical price for ecosystem services. Net primary production is used as a proxy for ecosystem services and, along with capital and labor, is used to estimate a Cobb Douglas production function from an international panel. A positive output elasticity for net primary production probably measures both marketed and nonmarketed contributions of ecosystems services. The production function is used to calculate the marginal product of net primary production, which is the shadow price for ecosystem services. The shadow price generally is greatest for developed nations, which have larger technical scalars and use less net primary production per unit output. The rate of technical substitution indicates that the quantity of capital needed to replace a unit of net primary production tends to increase with economic development, and this rate of replacement may ultimately constrain economic growth. (author)

  6. Primary production in the Kattegat - past and present

    DEFF Research Database (Denmark)

    Richardson, K.; Heilmann, Jens

    1995-01-01

    data collected during the period 1984-1993 are calculated using the method employed in the 1950s. It is concluded that primary production in the Kattegat has increased from less than 100 g C m(-2) y(- 1) to about 200 g C m(-2) y(-1) since the 1950s. This increase is not seen during the winter months...... to be responses to increases in primary production. However, for most areas, there are insufficient data to demonstrate whether or not increases in primary production have actually occurred. In this study, the evidence for increased primary production in the Kattegat is examined by comparing primary production...... measurements from the 1950s and measurements made in the period 1984-1993. The methods employed during the two periods differ considerably. These differences and how they may affect the validity of a comparison of the results from the studies carried out in two periods are addressed. The primary production...

  7. Nitrous oxide emissions of energy production

    International Nuclear Information System (INIS)

    Kinnunen, L.

    1998-01-01

    The share of energy production of the world-wide total N 2 O emissions is about 10 %. In 1991 the N 2 O emissions estimated to be up to 30 %. The previous estimates based on incorrect measurements. The measurement methods have been improved during the past few years. The present measurements have shown that the share of the combustion of fossil fuels is about 2.0 % and the share biomass combustion about 5.0 % of the total. The uncertainty of the values can be few percentage units. According to the present measurements the share of natural emissions and the fertilizers of the total N 2 O emissions is up to 60 %. The formation of nitrous oxide has been studied widely in various countries in the world. In Finland nitrous oxide has been studied in the national LIEKKI research programme. As a result of the research carried out in the programme it has been possible to reduce the formation of N 2 O by using appropriate catalysts and combustion technologies. Nitrous oxide is formed e.g. in fluidized-bed combustion of nitrogen containing fuels. The combustion temperature of other combustion methods is so high that the gas disintegrates in the furnace. By the new methods the nitrous oxide emissions of the fluidized-bed combustion has been possible to reduce from 100-200 ppm to the level less than 50 ppm of the flue gas volume. The Japanese research has shown that the nitrous oxide emissions of bubbling beds vary in between 58 - 103 ppm, but when combusting paper the emissions are 6 - 29 ppm. The corresponding value of circulating fluidized beds is 40 - 153 ppm

  8. Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production monitoring.

    Science.gov (United States)

    David P. Turner; William D. Ritts; Warren B. Cohen; Thomas K. Maeirsperger; Stith T. Gower; Al A. Kirschbaum; Steve W. Runnings; Maosheng Zhaos; Steven C. Wofsy; Allison L. Dunn; Beverly E. Law; John L. Campbell; Walter C. Oechel; Hyo Jung Kwon; Tilden P. Meyers; Eric E. Small; Shirley A. Kurc; John A. Gamon

    2005-01-01

    Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling...

  9. Copper(I)/TEMPO Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes with Ambient Air

    Science.gov (United States)

    Hoover, Jessica M.; Steves, Janelle E.; Stahl, Shannon S.

    2012-01-01

    This protocol describes a practical laboratory-scale method for aerobic oxidation of primary alcohols to aldehydes, using a chemoselective CuI/TEMPO catalyst system. The catalyst is prepared in situ from commercially available reagents, and the reactions are performed in a common organic solvent (acetonitrile) with ambient air as the oxidant. Three different reaction conditions and three procedures for the isolation and purification of the aldehyde product are presented. The oxidations of eight different alcohols, described here, include representative examples of each reaction condition and purification method. Reaction times vary from 20 min to 24 h, depending on the alcohol, while the purification methods each take about 2 h. The total time necessary for the complete protocol ranges from 3 – 26 h. PMID:22635108

  10. Global oceanic production of nitrous oxide

    Science.gov (United States)

    Freing, Alina; Wallace, Douglas W. R.; Bange, Hermann W.

    2012-01-01

    We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N2O) to estimate the concentration of biologically produced N2O and N2O production rates in the ocean on a global scale. Our approach to estimate the N2O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N2O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N2O are not taken into account in our study. The largest amount of subsurface N2O is produced in the upper 500 m of the water column. The estimated global annual subsurface N2O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr−1. This is in agreement with estimates of the global N2O emissions to the atmosphere and indicates that a N2O source in the mixed layer is unlikely. The potential future development of the oceanic N2O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed. PMID:22451110

  11. Global oceanic production of nitrous oxide.

    Science.gov (United States)

    Freing, Alina; Wallace, Douglas W R; Bange, Hermann W

    2012-05-05

    We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N(2)O) to estimate the concentration of biologically produced N(2)O and N(2)O production rates in the ocean on a global scale. Our approach to estimate the N(2)O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N(2)O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N(2)O are not taken into account in our study. The largest amount of subsurface N(2)O is produced in the upper 500 m of the water column. The estimated global annual subsurface N(2)O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr(-1). This is in agreement with estimates of the global N(2)O emissions to the atmosphere and indicates that a N(2)O source in the mixed layer is unlikely. The potential future development of the oceanic N(2)O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed.

  12. Oxidation of the Primary Alcoholic Moiety Selectively in the Presence of the Secondary Alcoholic Moieties

    International Nuclear Information System (INIS)

    Tin Myint Htwe

    2011-12-01

    Both primary and secondary alcoholic moieties are very sensitive to oxidation reactions. But sometimes it is necessary to oxidized only the primary alcoholic moiety. Such cases are usually found in Food Industries. In this situation, TEMPO (1, 1, 6, 6-Tetramethyl-1-Piperidine Oxoammonium) was used as an oxidizing agent. In this paper, Alpha starch was successfully oxidized using TEMPO as the oxidizing agent in combination with sodium hypochlorite with and without sodium bromide. The oxidation of primary alcoholic moiety only and the remaining untouched secondary alcoholic moiety were proved by infrared spectroscopy method.

  13. Fission product release into the primary coolant

    International Nuclear Information System (INIS)

    Apperson, C.E.

    1977-01-01

    The analytic evaluation of steady state primary coolant activity is discussed. The reported calculations account for temperature dependent fuel failure in two particle types and arbitrary radioactive decay chains. A matrix operator technique implemented in the SUVIUS code is used to solve the simultaneous equations. Results are compared with General Atomic Company's published results

  14. A review of ocean chlorophyll algorithms and primary production models

    Science.gov (United States)

    Li, Jingwen; Zhou, Song; Lv, Nan

    2015-12-01

    This paper mainly introduces the five ocean chlorophyll concentration inversion algorithm and 3 main models for computing ocean primary production based on ocean chlorophyll concentration. Through the comparison of five ocean chlorophyll inversion algorithm, sums up the advantages and disadvantages of these algorithm,and briefly analyzes the trend of ocean primary production model.

  15. Chemical phenomena in primary titanium production

    CSIR Research Space (South Africa)

    van Vuuren, DS

    2011-01-01

    Full Text Available TiO2 $ 490m p.a. $ 2500 p.a. Pigment Production ~20 kt TiO2 5100 kt TiO2 $ 37m p.a. $ 10000 m.p.a. Sponge Production Nil 125 kt p.a. Ti $ 1250 m.p.a. Ingot Production Nil 145 kt p.a. Ti $ 2600 m.p.a. Mill Products Nil ~90 kt p.a. Ti $ 4500 m... Museum Photo courtesy of the Kyushu National Museum http://web-japan.org/nipponia/nipponia38/en/travel/travel03.html V AL U E TiCl4 TiO2 Sponge Powder M2TiF6 Ingot INC R EAS ING COS T PRECURSOR REDUCTANT PRODUCT...

  16. Modeling of nitrous oxide production by autotrophic ammonia-oxidizing bacteria with multiple production pathways.

    Science.gov (United States)

    Ni, Bing-Jie; Peng, Lai; Law, Yingyu; Guo, Jianhua; Yuan, Zhiguo

    2014-04-01

    Autotrophic ammonia oxidizing bacteria (AOB) have been recognized as a major contributor to N2O production in wastewater treatment systems. However, so far N2O models have been proposed based on a single N2O production pathway by AOB, and there is still a lack of effective approach for the integration of these models. In this work, an integrated mathematical model that considers multiple production pathways is developed to describe N2O production by AOB. The pathways considered include the nitrifier denitrification pathway (N2O as the final product of AOB denitrification with NO2(-) as the terminal electron acceptor) and the hydroxylamine (NH2OH) pathway (N2O as a byproduct of incomplete oxidation of NH2OH to NO2(-)). In this model, the oxidation and reduction processes are modeled separately, with intracellular electron carriers introduced to link the two types of processes. The model is calibrated and validated using experimental data obtained with two independent nitrifying cultures. The model satisfactorily describes the N2O data from both systems. The model also predicts shifts of the dominating pathway at various dissolved oxygen (DO) and nitrite levels, consistent with previous hypotheses. This unified model is expected to enhance our ability to predict N2O production by AOB in wastewater treatment systems under varying operational conditions.

  17. Primary production in the Sulu Sea

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    its remotely sensed values from OCTS (Ocean Colour Temperature Scanner) are found to be in ... Although the Sulu Sea is more productive than the adjacent South China Sea, the central area ... surrounding ocean by a chain of islands.

  18. Studies of Heterogenous Palladium and Related Catalysts for Aerobic Oxidation of Primary Alcohols

    Science.gov (United States)

    Ahmed, Maaz S.

    Development of aerobic oxidation methods is of critical importance for the advancement of green chemistry, where the only byproduct produced is water. Recent work by our lab has produced an efficient Pd based heterogenous catalyst capable of preforming the aerobic oxidation of a wide spectrum of alcohols to either carboxylic acid or methyl ester. The well-defined catalyst PdBi 0.35Te0.23/C (PBT/C) catalyst has been shown to can perform the aerobic oxidation of alcohols to carboxylic acids in basic conditions. Additionally, we explored this catalyst for a wide range of alcohols and probed the nature of the selectivity of PBT/C for methyl esterification over other side products. Finally, means by which the catalyst operates with respect to oxidation states of the three components, Pd, Bi, and Te, was probed. Carboxylic acids are an important functional group due to their prevalence in various pharmaceutically active agents, agrochemicals, and commodity scale chemicals. The well-defined catalyst PBT/C catalyst was discovered to be effective for the oxidation of a wide spectrum of alcohols to carboxylic acid. The demonstrated substrate scope and functional group tolerance are the widest reported for an aerobic heterogeneous catalyst. Additionally, the catalyst has been implemented in a packed bed reactor with quantitative yield of benzoic acid maintained throughout a two-day run. Biomass derived 5-(hydroxymethyl)furfural (HMF) is also oxidized to 2,5-furandicarboxylic acid (FDCA) in high yield. Exploration of PBT/C for the oxidative methyl esterification was found to exhibit exquisite selectivity for the initial oxidation of primary alcohol instead of methanol, which is the bulk solvent. We explored this selectivity and conclude that it results from various substrate-surface interactions, which are not attainable by methanol. The primary alcohol can outcompete the methanol for binding on the catalyst surface through various interactions between the side chain of the

  19. Relative rates of nitric oxide and nitrous oxide production by nitrifiers, denitrifiers, and nitrate respirers

    Science.gov (United States)

    Anderson, I. C.; Levine, J. S.

    1986-01-01

    An account is given of the atmospheric chemical and photochemical effects of biogenic nitric and nitrous oxide emissions. The magnitude of the biogenic emission of NO is noted to remain uncertain. Possible soil sources of NO and N2O encompass nitrification by autotropic and heterotropic nitrifiers, denitrification by nitrifiers and denitrifiers, nitrate respiration by fermenters, and chemodenitrification. Oxygen availability is the primary determinant of these organisms' relative rates of activity. The characteristics of this major influence are presently investigated in light of the effect of oxygen partial pressure on NO and N2O production by a wide variety of common soil-nitrifying, denitrifying, and nitrate-respiring bacteria under laboratory conditions. The results obtained indicate that aerobic soils are primary sources only when there is sufficient moisture to furnish anaerobic microsites for denitrification.

  20. Interannual Variation in Phytoplankton Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile Severine; Gregg, Watson W.

    2013-01-01

    We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of four phytoplankton groups to the total primary production. First, we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms contributed the most to the total phytoplankton production ((is)approximately 50%, the equivalent of 20 PgC·y1). Coccolithophores and chlorophytes each contributed approximately 20% ((is) approximately 7 PgC·y1) of the total primary production and cyanobacteria represented about 10% ((is) approximately 4 PgC·y1) of the total primary production. Primary production by diatoms was highest in the high latitudes ((is) greater than 40 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4% (1-2 PgC·y1). We assessed the effects of climate variability on group-specific primary production using global (i.e., Multivariate El Niño Index, MEI) and "regional" climate indices (e.g., Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p (is) less than 0.05) between the MEI and the group-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatoms/cyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect

  1. Methods for forming complex oxidation reaction products including superconducting articles

    International Nuclear Information System (INIS)

    Rapp, R.A.; Urquhart, A.W.; Nagelberg, A.S.; Newkirk, M.S.

    1992-01-01

    This patent describes a method for producing a superconducting complex oxidation reaction product of two or more metals in an oxidized state. It comprises positioning at least one parent metal source comprising one of the metals adjacent to a permeable mass comprising at least one metal-containing compound capable of reaction to form the complex oxidation reaction product in step below, the metal component of the at least one metal-containing compound comprising at least a second of the two or more metals, and orienting the parent metal source and the permeable mass relative to each other so that formation of the complex oxidation reaction product will occur in a direction towards and into the permeable mass; and heating the parent metal source in the presence of an oxidant to a temperature region above its melting point to form a body of molten parent metal to permit infiltration and reaction of the molten parent metal into the permeable mass and with the oxidant and the at least one metal-containing compound to form the complex oxidation reaction product, and progressively drawing the molten parent metal source through the complex oxidation reaction product towards the oxidant and towards and into the adjacent permeable mass so that fresh complex oxidation reaction product continues to form within the permeable mass; and recovering the resulting complex oxidation reaction product

  2. On Tour... Primary Hardwood Processing, Products and Recycling Unit

    Science.gov (United States)

    Philip A. Araman; Daniel L. Schmoldt

    1995-01-01

    Housed within the Department of Wood Science and Forest Products at Virginia Polytechnic Institute is a three-person USDA Forest Service research work unit (with one vacancy) devoted to hardwood processing and recycling research. Phil Araman is the project leader of this truly unique and productive unit, titled ãPrimary Hardwood Processing, Products and Recycling.ä The...

  3. Primary energy sources for hydrogen production

    International Nuclear Information System (INIS)

    Hassmann, K.; Kuehne, H.M.

    1993-01-01

    The costs for hydrogen production through water electrolysis are estimated, assuming the electricity is produced from solar, hydro-, fossil, or nuclear power. The costs for hydrogen end-use in the power generation, heat and transportation sectors are also calculated, based on a state of the art technology and a more advanced technology expected to represent the state by the year 2010. The costs for hydrogen utilization (without energy taxes) are shown to be higher than current prices for fossil fuels (including taxes). Without restrictions imposed on fossil fuel consumption, hydrogen shall not gain a significant market share in either of the cases discussed. 2 figs., 3 tabs., 4 refs

  4. Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2016-11-01

    Full Text Available The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC. Levels of reactive oxygen species (ROS, malondialdehyde (MDA, and glutathione (GSH, activities of superoxide dismutase (SOD and catalase (CAT, mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

  5. Work Environment and Productivity among Primary School Teachers ...

    African Journals Online (AJOL)

    User

    International Multidisciplinary Journal, Ethiopia. Vol. 5 (5), Serial No. ... work environment of Nigeria primary school teachers to greater productivity ... changes on the structure and curriculum, recommend and prescribed teaching methods and ...

  6. UV radiation and primary production in the Antarctic waters

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Krishnakumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

    at 683 nm), scalar irradiance (photosynthetically active radiation (PAR), computed primary production (pp), diffuse attenuation coefficient, and UVB (308 and 320 nm) and UVA (340 and 380 nm) radiation and ocean temperature all measured as a function...

  7. HANPP Collection: Global Patterns in Net Primary Productivity (NPP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Net Primary Productivity (NPP) portion of the HANPP Collection maps the net amount of solar energy converted to plant organic matter through...

  8. Solid oxide fuel cells and hydrogen production

    International Nuclear Information System (INIS)

    Dogan, F.

    2009-01-01

    'Full text': A single-chamber solid oxide fuel cell (SC-SOFC), operating in a mixture of fuel and oxidant gases, provides several advantages over the conventional SOFC such as simplified cell structure (no sealing required). SC-SOFC allows using a variety of fuels without carbon deposition by selecting appropriate electrode materials and cell operating conditions. The operating conditions of single chamber SOFC was studied using hydrocarbon-air gas mixtures for a cell composed of NiO-YSZ / YSZ / LSCF-Ag. The cell performance and catalytic activity of the anode was measured at various gas flow rates. The results showed that the open-circuit voltage and the power density increased as the gas flow rate increased. Relatively high power densities up to 660 mW/cm 2 were obtained in a SC-SOFC using porous YSZ electrolytes instead of dense electrolytes required for operation of a double chamber SOFC. In addition to propane- or methane-air mixtures as a fuel source, the cells were also tested in a double chamber configuration using hydrogen-air mixtures by controlling the hydrogen/air ratio at the cathode and the anode. Simulation of single chamber conditions in double chamber configurations allows distinguishing and better understanding of the electrode reactions in the presence of mixed gases. Recent research efforts; the effect of hydrogen-air mixtures as a fuel source on the performance of anode and cathode materials in single-chamber and double-chamber SOFC configurations,will be presented. The presentation will address a review on hydrogen production by utilizing of reversible SOFC systems. (author)

  9. Visible-Light-Promoted Metal-Free Aerobic Oxidation of Primary Amines to Acids and Lactones.

    Science.gov (United States)

    Cheng, Xiaokai; Yang, Bo; Hu, Xingen; Xu, Qing; Lu, Zhan

    2016-12-05

    A unique metal-free aerobic oxidation of primary amines via visible light photocatalytic double carbon-carbon bonds cleavage and multi carbon-hydrogen bonds oxidation was observed. Aerobic oxidation of primary amines could be controlled to afford acids by using dioxane with 18 W CFL, and lactones by using DMF with 8 W green LEDs, respectively. A plausible mechanism was proposed based on control experiments. This observation showed direct evidences for the fragmentation in the aerobic oxidation of aliphatic primary amines. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Azobisisobutyronitrile initiated aerobic oxidative transformation of amines: coupling of primary amines and cyanation of tertiary amines.

    Science.gov (United States)

    Liu, Lianghui; Wang, Zikuan; Fu, Xuefeng; Yan, Chun-Hua

    2012-11-16

    In the presence of a catalytic amount of radical initiator AIBN, primary amines are oxidatively coupled to imines and tertiary amines are cyanated to α-aminonitriles. These "metal-free" aerobic oxidative coupling reactions may find applications in a wide range of "green" oxidation chemistry.

  11. Deposition and incorporation of corrosion product to primary coolant suppressing method

    International Nuclear Information System (INIS)

    Tsuzuki, Yasuo; Hasegawa, Naoyoshi; Fujioka, Tsunaaki.

    1992-01-01

    In a PWR type nuclear power plant, the concentration of dissolved nitrogen in primary coolants is increased by controlling the nitrogen partial pressure in a volume controlling tank gas phase portion or addition of water in a primary system water supply tank containing dissolved nitrogen to a primary system. Then ammonium is formed by a reaction with hydrogen dissolved in the primary coolants in the field of radiation rays, to control the concentration of ammonium in the coolants within a range from 0.5 to 3.5 ppm, and operate the power plant. As a result, deposition and incorporation of corrosion products to the structural materials of the primary system equipments during plant operation (pH 6.8 to 8.0) are suppressed. In other words, deposition of particulate corrosion products on the surface of fuel cladding tubes and the inner surface of pipelines in the primary system main equipments is prevented and incorporation of ionic radioactive corrosion products to the oxide membranes on the inner surface of the pipelines of the primary system main equipments is suppressed, to greatly reduce the radiation dose rate of the primary system pipelines. Thus, operator's radiation exposure can be decreased upon shut down of the plant. (N.H.)

  12. Oxidation kinetics of reaction products formed in uranium metal corrosion

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    1998-01-01

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O 2 and Ar-20%O 2 were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates

  13. Oxidation kinetics of reaction products formed in uranium metal corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Totemeier, T. C.

    1998-04-22

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O{sub 2} and Ar-20%O{sub 2} were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates.

  14. Do Offshore Wind Farms Influence Marine Primary Production?

    Science.gov (United States)

    Tweddle, J. F.; Murray, R. B. O.; Gubbins, M.; Scott, B. E.

    2016-02-01

    Primary producers (phytoplankton) form the basis of marine food-webs, supporting production of higher trophic levels, and act as a sink of CO2. We considered the impact of proposed large scale offshore wind farms in moderately deep waters (> 45 m) off the east coast of Scotland on rates of primary production. A 2 stage modelling process was used, employing state-of-the-art 3-D hydrographic models with the ability to capture flow at the spatial resolution of 10 m combined with 1-D vertical modelling using 7 years of local forcing data. Through influencing the strength of stratification via changes in current flow, large (100 m) modelled wind turbine foundations had a significant effect on primary producers, consistently reducing total annual primary production, although within the range of natural interannual variability. The percentage reduction was largest over submarine banks less than 54 m in depth, and was outside the range of natural interannual variability. Smaller (10 m) turbine foundations had no discernible effect on total annual primary production. The results indicate that smaller foundations should be favored as a mitigation measure, in terms of effects on primary production, and this type of analysis should be considered within sectoral planning and licensing processes for future renewable energy developments.

  15. Chlorine as a primary radical: evaluation of methods to understand its role in initiation of oxidative cycles

    Science.gov (United States)

    Young, C. J.; Washenfelder, R. A.; Edwards, P. M.; Parrish, D. D.; Gilman, J. B.; Kuster, W. C.; Mielke, L. H.; Osthoff, H. D.; Tsai, C.; Pikelnaya, O.; Stutz, J.; Veres, P. R.; Roberts, J. M.; Griffith, S.; Dusanter, S.; Stevens, P. S.; Flynn, J.; Grossberg, N.; Lefer, B.; Holloway, J. S.; Peischl, J.; Ryerson, T. B.; Atlas, E. L.; Blake, D. R.; Brown, S. S.

    2014-04-01

    The role of chlorine atoms (Cl) in atmospheric oxidation has been traditionally thought to be limited to the marine boundary layer, where they are produced through heterogeneous reactions involving sea salt. However, recent observation of photolytic Cl precursors (ClNO2 and Cl2) formed from anthropogenic pollution has expanded the potential importance of Cl to include coastal and continental urban areas. Measurements of ClNO2 in Los Angeles during CalNex (California Nexus - Research at the Nexus of Air Quality and Climate Change) showed it to be an important primary (first generation) radical source. Evolution of ratios of volatile organic compounds (VOCs) has been proposed as a method to quantify Cl oxidation, but we find no evidence from this approach for a significant role of Cl oxidation in Los Angeles. We use a box model with the Master Chemical Mechanism (MCM v3.2) chemistry scheme, constrained by observations in Los Angeles, to examine the Cl sensitivity of commonly used VOC ratios as a function of NOx and secondary radical production. Model results indicate VOC tracer ratios could not detect the influence of Cl unless the ratio of [OH] to [Cl] was less than 200 for at least a day. However, the model results also show that secondary (second generation) OH production resulting from Cl oxidation of VOCs is strongly influenced by NOx, and that this effect obscures the importance of Cl as a primary oxidant. Calculated concentrations of Cl showed a maximum in mid-morning due to a photolytic source from ClNO2 and loss primarily to reactions with VOCs. The [OH] to [Cl] ratio was below 200 for approximately 3 h in the morning, but Cl oxidation was not evident from the measured ratios of VOCs. Instead, model simulations show that secondary OH production causes VOC ratio evolution to follow that expected for OH oxidation, despite the significant input of primary Cl from ClNO2 photolysis in the morning. Even though OH is by far the dominant oxidant in Los Angeles, Cl

  16. Production and Utilization of Core-Textbooks in Primary School ...

    African Journals Online (AJOL)

    Production and Utilization of Core-Textbooks in Primary School System: Impact of Authors and Publishers. ... These stakeholders have specific roles to play and cannot operate in isolation. The study, therefore investigated the influence of authorship and publishers on core textbook production and utilisation in Oyo State ...

  17. MODIS-derived terrestrial primary production [chapter 28

    Science.gov (United States)

    Maosheng Zhao; Steven Running; Faith Ann Heinsch; Ramakrishna Nemani

    2011-01-01

    Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems not only create environments suitable for human habitation, but also provide materials essential for survival, such as food, fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of...

  18. Physical control of primary productivity on a seasonal scale in ...

    Indian Academy of Sciences (India)

    Keywords. Primary production; upwelling; winter cooling; Ekman-pumping, nutrient transport; Arabian Sea ... on the other hand, is driven by advection from the Somalia upwelling. Surface cooling and convection resulting from reduced solar radiation and increased evaporation make the northern region productive in winter.

  19. Primary productivity in nearshore waters of Thal, Maharashtra coast

    Digital Repository Service at National Institute of Oceanography (India)

    Varshney, P.K.; Nair, V.R.; Abidi, S.A.H.

    Primary productivity off Thal, Maharashtra, India was evaluated at 3 stations during Feb. 1980 to Jan. 1981. The area was quite turbid and the euphotic zone never exceeded 2.5 m. Column production ranged from 0.69 to 605.21 mg C.m/2.d/2 (av. 78.2 mg...

  20. Serum uric acid levels and leukocyte nitric oxide production in multiple sclerosis patients outside relapses

    NARCIS (Netherlands)

    Mostert, JP; Ramsaransing, GSM; Heerserna, DJ; Heerings, M; Wilczak, N; De Keyser, J

    2005-01-01

    Background: A number of studies found that patients with multiple sclerosis (MS) have low serum levels of uric acid. It is unclear whether this represents a primary deficit or secondary effect. Uric acid is a scavenger of peroxynitrite, which is the product of nitric oxide (NO) and superoxide.

  1. Oxidative Stability and Sensory Attributes of Fermented Milk Product Fortified with Fish Oil and Marine Phospholipids

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Thomsen, Birgitte Raagaard; Hyldig, Grethe

    2013-01-01

    Marine phospholipids (PL) are potential ingredients for food fortification due to its numerous advantages. The main objective of this study was to investigate whether a fermented milk product fortified with a mixture of marine PL and fish oil had better oxidative stability than a fermented milk...... product fortified with fish oil alone. Fortification of a fermented milk product with marine PL was performed by incorporating 1 % w/w lipids, either in the form of neat oil or in the form of a pre-emulsion. Lipid oxidation was investigated in the neat emulsions and fortified products by the measurements...... of primary, secondary volatile oxidation products and tocopherol content upon 32 days storage at 2 °C and 28 days storage at 5 °C, respectively. Analyses of particle size distribution, viscosity and microbial growth were also performed. In addition, sensory attributes such as sour, fishy and rancid flavor...

  2. HANPP Collection: Human Appropriation of Net Primary Productivity (HANPP) by Country and Product

    Data.gov (United States)

    National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) by Country and Product portion of the HANPP Collection contains tabular data on carbon-equivalents of...

  3. New oxidation and photo-oxidation products of tryptophan

    International Nuclear Information System (INIS)

    Savige, W.E.

    1975-01-01

    Dye-sensitized photo-oxidation of tryptophan in water gives N'-formylkynurenine and (+-)-3a-hydroxy-1,2,3a,8,8a-hexahydropyrrolo[2,3-b] indole-2-carboxylic acid. The latter rearranges to oxindolyl-3-alanine on irradiation with UV light and reacts with thiols, including cysteine, in warm 20% acetic acid to give the corresponding 2-tryptophyl sulphides. (orig.) [de

  4. The 2010 spring drought reduced primary productivity in southwestern China

    International Nuclear Information System (INIS)

    Zhang Li; Li Jing; Xiao Jingfeng; Wang Kun; Lei Liping; Guo Huadong

    2012-01-01

    Many parts of the world experience frequent and severe droughts. Summer drought can significantly reduce primary productivity and carbon sequestration capacity. The impacts of spring droughts, however, have received much less attention. A severe and sustained spring drought occurred in southwestern China in 2010. Here we examine the influence of this spring drought on the primary productivity of terrestrial ecosystems using data on climate, vegetation greenness and productivity. We first assess the spatial extent, duration and severity of the drought using precipitation data and the Palmer drought severity index. We then examine the impacts of the drought on terrestrial ecosystems using satellite data for the period 2000–2010. Our results show that the spring drought substantially reduced the enhanced vegetation index (EVI) and gross primary productivity (GPP) during spring 2010 (March–May). Both EVI and GPP also substantially declined in the summer and did not fully recover from the drought stress until August. The drought reduced regional annual GPP and net primary productivity (NPP) in 2010 by 65 and 46 Tg C yr −1 , respectively. Both annual GPP and NPP in 2010 were the lowest over the period 2000–2010. The negative effects of the drought on annual primary productivity were partly offset by the remarkably high productivity in August and September caused by the exceptionally wet conditions in late summer and early fall and the farming practices adopted to mitigate drought effects. Our results show that, like summer droughts, spring droughts can also have significant impacts on vegetation productivity and terrestrial carbon cycling. (letter)

  5. Benthic primary production and mineralization in a High Arctic Fjord

    DEFF Research Database (Denmark)

    Attard, Karl M.; Hancke, Kasper; Sejr, Mikael K.

    2016-01-01

    Coastal and shelf systems likely exert major influence on Arctic Ocean functioning, yet key ecosystem processes remain poorly quantified. We employed the aquatic eddy covariance (AEC) oxygen (O2) flux method to estimate benthic primary production and mineralization in a High Arctic Greenland fjord....... Seabed gross primary production (GPP) within the 40 m deep photic zone was highest at 10 m (29 mmol O2 m−2 d−1) and decreased to 5 mmol O2 m−2 d−1 at 40 m, while nighttime community respiration (CR) ranged from 11 to 25 mmol O2m−2 d−1. CR decreased to ~2.5 mmol O2m−2 d−1 at 80 m and remained constant...... with further depth. Fauna activity accounted for ~50% of the CR at depths ≤60 m but was primary production...

  6. Oxidative stress is involved in Dasatinib-induced apoptosis in rat primary hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Tao; Luo, Peihua; Zhu, Hong; Zhao, Yuqin [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Wu, Honghai; Gai, Renhua; Wu, Youping [Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); Yang, Bo [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaochun, E-mail: yangxiaochun@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); He, Qiaojun, E-mail: qiaojunhe@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China)

    2012-06-15

    Dasatinib, a multitargeted inhibitor of BCR–ABL and SRC kinases, exhibits antitumor activity and extends the survival of patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL). However, some patients suffer from hepatotoxicity, which occurs through an unknown mechanism. In the present study, we found that Dasatinib could induce hepatotoxicity both in vitro and in vivo. Dasatinib reduced the cell viability of rat primary hepatocytes, induced the release of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in vitro, and triggered the ballooning degeneration of hepatocytes in Sprague–Dawley rats in vivo. Apoptotic markers (chromatin condensation, cleaved caspase-3 and cleaved PARP) were detected to indicate that the injury induced by Dasatinib in hepatocytes in vitro was mediated by apoptosis. This result was further validated in vivo using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays. Here we found that Dasatinib dramatically increased the level of reactive oxygen species (ROS) in hepatocytes, reduced the intracellular glutathione (GSH) content, attenuated the activity of superoxide dismutase (SOD), generated malondialdehyde (MDA), a product of lipid peroxidation, decreased the mitochondrial membrane potential, and activated nuclear factor erythroid 2-related factor 2 (Nrf2) and mitogen-activated protein kinases (MAPK) related to oxidative stress and survival. These results confirm that oxidative stress plays a pivotal role in Dasatinib-mediated hepatotoxicity. N-acetylcysteine (NAC), a typical antioxidant, can scavenge free radicals, attenuate oxidative stress, and protect hepatocytes against Dasatinib-induced injury. Thus, relieving oxidative stress is a viable strategy for reducing Dasatinib-induced hepatotoxicity. -- Highlights: ►Dasatinib shows potential hepatotoxicity both in vitro and in vivo. ►Apoptosis plays a vital role in Dasatinib

  7. Clinical productivity of primary care nurse practitioners in ambulatory settings.

    Science.gov (United States)

    Xue, Ying; Tuttle, Jane

    Nurse practitioners are increasingly being integrated into primary care delivery to help meet the growing demand for primary care. It is therefore important to understand nurse practitioners' productivity in primary care practice. We examined nurse practitioners' clinical productivity in regard to number of patients seen per week, whether they had a patient panel, and patient panel size. We further investigated practice characteristics associated with their clinical productivity. We conducted cross-sectional analysis of the 2012 National Sample Survey of Nurse Practitioners. The sample included full-time primary care nurse practitioners in ambulatory settings. Multivariable survey regression analyses were performed to examine the relationship between practice characteristics and nurse practitioners' clinical productivity. Primary care nurse practitioners in ambulatory settings saw an average of 80 patients per week (95% confidence interval [CI]: 79-82), and 64% of them had their own patient panel. The average patient panel size was 567 (95% CI: 522-612). Nurse practitioners who had their own patient panel spent a similar percent of time on patient care and documentation as those who did not. However, those with a patient panel were more likely to provide a range of clinical services to most patients. Nurse practitioners' clinical productivity was associated with several modifiable practice characteristics such as practice autonomy and billing and payment policies. The estimated number of patients seen in a typical week by nurse practitioners is comparable to that by primary care physicians reported in the literature. However, they had a significantly smaller patient panel. Nurse practitioners' clinical productivity can be further improved. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Behaviour of fission products in PWR primary coolant and defected fuel rods evaluation

    International Nuclear Information System (INIS)

    Bourgeois, P.; Stora, J.P.

    1979-01-01

    The activity surveillance of the PWR primary coolant by γ spectometry gives some informations on fuel failures. The activity of different nuclides e.g. Xenons, Kryptons, Iodines, can be correlated with the number of the defected fuel rods. Therefore the precharacterization with eventually a prelocalization of the related fuel assemblies direct the sipping-test and allows a saving of time during refueling. A model is proposed to calculate the number of the defected rods from the activity measurements of the primary coolant. A semi-empirical model of the release of the fission products has been built from the activity measurements of the primary coolant in a 900 MWe PWR. This model allows to calculate the number of the defected rods and also a typical parameter of the mean damage. Fission product release is described by three stages: release from uranium dioxide, transport across the gas gap and behaviour in the primary coolant. The model of release from the oxide considers a diffusion process in the grains with trapping. The release then occurs either directly to free surfaces or with a delay due to a transit into closed porosity of the oxide. The amount released is the same for iodine and rare gas. With the gas gap transit is associated a transport time and a probability of trapping for the iodines. In the primary coolant the purification and the radioactive decay are considered. (orig.)

  9. Nano cobalt oxides for photocatalytic hydrogen production

    KAUST Repository

    Mangrulkar, Priti A.; Joshi, Meenal M.; Tijare, Saumitra N.; Polshettiwar, Vivek; Labhsetwar, Nitin K.; Rayalu, Sadhana Suresh

    2012-01-01

    of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  10. Comparison of Endoflas and Zinc oxide Eugenol as root canal filling materials in primary dentition

    Directory of Open Access Journals (Sweden)

    Nivedita Rewal

    2014-01-01

    Full Text Available Background: Zinc oxide eugenol has long been the material of choice of pediatric dentists worldwide, although it fails to meet the ideal requirements of root canal filling material for primary teeth. Endoflas, a mixture of zinc oxide eugenol, calcium hydroxide, and iodoform, can be considered to be an effective root canal filling material in primary teeth as compared with zinc oxide eugenol. This study was carried out to compare zinc oxide eugenol with endoflas for pulpectomy in primary dentition. Aim: The objective of the study was to compare clinically and radiographically success rates of zinc oxide eugenol with endoflas for the root canal filling of primary teeth at 3, 6, and 9 months. Design: Fifty primary molars were included in the study with 26 teeth in Group I (Endoflas and 24 in Group II (zinc oxide eugenol. A single visit pulpectomy was carried out. Results: The overall success rate of zinc oxide eugenol was 83% whereas 100% success was found in the case of endoflas. The obtained results were compiled and subjected to statistical analysis using the chi-square test. The difference in the success rate between the two was statistically significant (P < 0.05. Conclusion: Endoflas has shown to have better results than zinc oxide eugenol. It should therefore be the material of choice for root canal treatment in deciduous dentition.

  11. Nano cobalt oxides for photocatalytic hydrogen production

    KAUST Repository

    Mangrulkar, Priti A.

    2012-07-01

    Nano structured metal oxides including TiO 2, Co 3O 4 and Fe 3O 4 have been synthesized and evaluated for their photocatalytic activity for hydrogen generation. The photocatalytic activity of nano cobalt oxide was then compared with two other nano structured metal oxides namely TiO 2 and Fe 3O 4. The synthesized nano cobalt oxide was characterized thoroughly with respect to EDX and TEM. The yield of hydrogen was observed to be 900, 2000 and 8275 mmol h -1 g -1 of photocatalyst for TiO 2, Co 3O 4 and Fe 3O 4 respectively under visible light. It was observed that the hydrogen yield in case of nano cobalt oxide was more than twice to that of TiO 2 and the hydrogen yield of nano Fe 3O 4 was nearly four times as compared to nano Co 3O 4. The influence of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  12. Characterization of oxidation end product of plasma albumin 'in vivo'.

    Science.gov (United States)

    Musante, Luca; Bruschi, Maurizio; Candiano, Giovanni; Petretto, Andrea; Dimasi, Nazzareno; Del Boccio, Piero; Urbani, Andrea; Rialdi, Giovanni; Ghiggeri, Gian Marco

    2006-10-20

    Anti-oxidants are paradoxically much lower in plasma than inside cells even blood is comparably exposed to the oxidative stress. 'In vitro' models suggest a critical role of albumin as substitutive anti-oxidant in plasma but no proof for this role is available 'in vivo.' Herein, we demonstrate by LC/MS/MS that plasma albumin undergoes massive oxidation in primary nephrotic syndrome, involving stable sulphonation SO3- of the free SH of Cys 34 with +48Da increase in exact mass of the protein (ESI-MS) and formation of a fast moving isoform in the pH range between 5 and 7. Physical-chemical experiments with DSC and fluorescence spectra indicate a thermal stabilization of the structure upon oxidation. This is the first demonstration of massive oxidation of albumin 'in vivo' that reflects a functional role of the protein. Free radicals should be implicated in the pathogenesis of proteinuria in human FSGS.

  13. Nitric oxide is a mediator of methamphetamine (METH)-induced neurotoxicity. In vitro evidence from primary cultures of mesencephalic cells.

    Science.gov (United States)

    Sheng, P; Cerruti, C; Ali, S; Cadet, J L

    1996-10-31

    METH is a monoaminergic toxic that destroys dopamine terminals in vivo. Oxidative mechanisms associated with DA metabolism are thought to play an important role in its toxic effects. These ideas were supported by the demonstration that CuZn-superoxide dismutase (CuZnSOD) transgenic mice were protected against the toxic effects of the drug. In the present study, we sought to determine if nitric oxide (NO) production was also involved in METH-induced neurotoxicity using primary cultures obtained from fetal rat mesencephalon. METH caused dose- and time-dependent cell death in vitro. Blockade of nitric oxide (NO) formation with several nitric oxide (NO) synthase blockers attenuated METH-mediated toxicity. Moreover, inhibition of ADP-ribosylation with nicotinamide and benzamide also provided protection against the toxicity of the drug. These results, together with our previous results in transgenic mice, support a role for free radicals in METH-induced toxic effects.

  14. Anthropogenic climate change has altered primary productivity in Lake Superior.

    Science.gov (United States)

    O'Beirne, M D; Werne, J P; Hecky, R E; Johnson, T C; Katsev, S; Reavie, E D

    2017-06-09

    Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production. Furthermore, data from the last century indicate a rapid increase in primary production, which we attribute to increasing surface water temperatures and longer seasonal stratification related to longer ice-free periods in Lake Superior due to anthropogenic climate warming. These observations demonstrate that anthropogenic effects have become a prominent influence on one of Earth's largest, most pristine lacustrine ecosystems.

  15. Seasonality of primary and secondary production in an Arctic river

    Science.gov (United States)

    Kendrick, M.; Huryn, A.; Deegan, L.

    2011-12-01

    Rivers and streams that freeze solid for 8-9 months each year provide excellent examples of the extreme seasonality of arctic habitats. The communities of organisms inhabiting these rivers must complete growth and development during summer, resulting in a rapid ramp-up and down of production over the short ice-free period. The effects of recent shifts in the timing of the spring thaw and autumn freeze-up on the duration and pattern of the period of active production are poorly understood. We are currently investigating: 1) the response of the biotic community of the Kuparuk River (Arctic Alaska) to shifts in the seasonality of the ice-free period, and 2) the community response to increases in phosphorous (P) supply anticipated as the volume of the permafrost active-layer increases in response to climate warming. Here algal production supports a 2-tier web of consumers. We tracked primary and secondary production from the spring thaw through mid-August in a reference reach and one receiving low-level P fertilization. Gross primary production/community respiration (GPP/R) ratios for both reaches were increasing through mid-July, with higher GPP/R in response to the P addition. Understanding the degree of synchrony between primary and secondary production in this Arctic river system will enhance further understanding of how shifts in seasonality affect trophic dynamics.

  16. Decadal Changes in Global Ocean Annual Primary Production

    Science.gov (United States)

    Gregg, Watson; Conkright, Margarita E.; Behrenfeld, Michael J.; Ginoux, Paul; Casey, Nancy W.; Koblinsky, Chester J. (Technical Monitor)

    2002-01-01

    The Sea-viewing Wide Field-of-View Sensor (SeaWiFS) has produced the first multi-year time series of global ocean chlorophyll observations since the demise of the Coastal Zone Color Scanner (CZCS) in 1986. Global observations from 1997-present from SeaWiFS combined with observations from 1979-1986 from the CZCS should in principle provide an opportunity to observe decadal changes in global ocean annual primary production, since chlorophyll is the primary driver for estimates of primary production. However, incompatibilities between algorithms have so far precluded quantitative analysis. We have developed and applied compatible processing methods for the CZCS, using modern advances in atmospheric correction and consistent bio-optical algorithms to advance the CZCS archive to comparable quality with SeaWiFS. We applied blending methodologies, where in situ data observations are incorporated into the CZCS and SeaWiFS data records, to provide improvement of the residuals. These re-analyzed, blended data records provide maximum compatibility and permit, for the first time, a quantitative analysis of the changes in global ocean primary production in the early-to-mid 1980's and the present, using synoptic satellite observations. An intercomparison of the global and regional primary production from these blended satellite observations is important to understand global climate change and the effects on ocean biota. Photosynthesis by chlorophyll-containing phytoplankton is responsible for biotic uptake of carbon in the oceans and potentially ultimately from the atmosphere. Global ocean annual primary decreased from the CZCS record to SeaWiFS, by nearly 6% from the early 1980s to the present. Annual primary production in the high latitudes was responsible for most of the decadal change. Conversely, primary production in the low latitudes generally increased, with the exception of the tropical Pacific. The differences and similarities of the two data records provide evidence

  17. Nitrogenous nutrients and primary production in a tropical oceanic environment

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; Devassy, V.P.

    Measurements of the concentrations of nitrogenous nutrients and primary production were made at 10 stations along 8 degrees N and 10 degrees N in the tropical oceanic Lakshadweep waters Inorganic nitrogen (NO3, NO2 and NH4) accounted for less than...

  18. Anoxic and oxic phototrophic primary production during the Precambrian

    DEFF Research Database (Denmark)

    Ebey-Honeycutt, Christina Marie; Bjerrum, Christian J.; Canfield, Donald Eugene

    2009-01-01

    of the mixed layer often lies above the base of the photic zone . Thus, an ecosystem model for the Precambrian should reflect the net primary production (NPP) of oxygenic phototrophs in the mixed layer and anoxygenic phototrophs below (NPPox and NPPred, respectively). Satelite data and a vertically generalized...

  19. The Evonik-Uhde HPPO process for proplene oxide production

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, B.; Baerz, M. [Evonik Industries, Hanau (Germany); Schemel, J.; Kolbe, B. [Uhde GmbH, Dortmund/Bad Soden (Germany)

    2011-07-01

    In 2008 the HPPO technology has shown up as an economically and environmentally friendly alternative for manufacturing of propylene oxide. The HPPO technology offers the advantage of an on purpose process for manufacturing of propylene oxide without dependency on disposal or marketing of coupling products. (orig.)

  20. Catalytic abatement of nitrous oxide from nitric and production

    NARCIS (Netherlands)

    Oonk, J.

    1998-01-01

    Nitric acid production is identified as a main source of nitrous oxide. Options for emission reduction however are not available. TNO and Hydro Agri studied the technological and economic feasibility of catalytic decomposition of nitrous oxide in nitric acid tail-gases. Although in literature

  1. Production of beryllium oxide of nuclear purity from beryl

    Energy Technology Data Exchange (ETDEWEB)

    Copat, A; Sood, S P

    1984-01-01

    Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740/sup 0/C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide

  2. Production of beryllium oxide of nuclear purity from beryl

    International Nuclear Information System (INIS)

    Copat, A.; Sood, S.P.

    1983-01-01

    Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740 0 C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide (Author) [pt

  3. A primary reduced TCA flux governs substrate oxidation in T2D skeletal muscle

    DEFF Research Database (Denmark)

    Gaster, Michael

    2012-01-01

    Our current knowledge on substrate oxidation in skeletal muscle in relation to insulin resistance and type 2 diabetes (T2D) originate mainly from in vivo studies. The oxidative capacity of skeletal muscle is highly influenced by physical activity, ageing, hormonal status, and fiber type composition...... further regulatory mechanism to our understanding of substrate oxidation in human skeletal muscle during normo- an pathophysiological conditions, focusing especially on the governing influence of a primary reduced TCA flux for the diabetic phenotype in skeletal muscle....

  4. Chemical oxidation of unsymmetrical dimethylhydrazine transformation products in water

    NARCIS (Netherlands)

    Abilev, M.; Kenessov, B.N.; Batyrbekova, S.; Grotenhuis, J.T.C.

    2015-01-01

    Oxidation of unsymmetrical dimethylhydrazine (UDMH) during a water treatment has several disadvantages including formation of stable toxic byproducts. Effectiveness of treatment methods in relation to UDMH transformation products is currently poorly studied. This work considers the effectiveness of

  5. 40 CFR 415.50 - Applicability; description of the calcium oxide production subcategory.

    Science.gov (United States)

    2010-07-01

    ... calcium oxide production subcategory. 415.50 Section 415.50 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Oxide Production Subcategory § 415.50 Applicability; description of the calcium... the production of calcium oxide. ...

  6. Method for production of transparent yttrium oxide

    International Nuclear Information System (INIS)

    Dutta, S.K.; Gazza, G.A.

    1975-01-01

    The method comprises vacuum hot pressing the yttrium oxide (Y 2 O 3 ) powder in a graphite die at temperatures of between 1300 to 1500 0 C and uniaxial pressures of between 5000 to 7000 psi, for a period of 1 to 2 hours. (U.S.)

  7. Cholesterol oxidation products and their biological importance

    Czech Academy of Sciences Publication Activity Database

    Kulig, W.; Cwiklik, Lukasz; Jurkiewicz, P.; Rog, T.; Vattulainen, I.

    2016-01-01

    Roč. 199, Sep (2016), s. 144-160 ISSN 0009-3084 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388963 Keywords : cholesterol * oxidation * oxysterols * biological membranes * biophysical properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.361, year: 2016

  8. NADPH oxidases in Microglia oxidant production

    DEFF Research Database (Denmark)

    Haslund-Vinding, J; McBean, G; Jaquet, V

    2017-01-01

    inhibitors. Finally, we review the recent literature on NOX and other sources of ROS that are involved in activation of the inflammasome and discuss the potential influence of microglia-derived oxidants on neurogenesis, neural differentiation and culling of surplus progenitor cells. The degree to which...

  9. Cholesterol oxidation products and their biological importance

    Czech Academy of Sciences Publication Activity Database

    Kulig, W.; Cwiklik, Lukasz; Jurkiewicz, Piotr; Rog, T.; Vattulainen, I.

    2016-01-01

    Roč. 199, SI (2016), s. 144-160 ISSN 0009-3084 R&D Projects: GA ČR(CZ) GBP208/12/G016; GA ČR GA15-14292S Institutional support: RVO:61388955 Keywords : cholesterol * oxidation * oxysterols Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.361, year: 2016

  10. Lipid oxidation. Part 2. Oxidation products of olive oil methyl esters.

    Science.gov (United States)

    Pokorný, J; Tài, P; Parízková, H; Smidrkalová, E; El-Tarras, M F; Janícek, G

    1976-01-01

    Olive oil was converted into methyl esters which were autoxidized at 60 degrees C. The composition of oxidized products was determined by the comparison of infrared spectra and NMR spectra of the original and acetylated samples, the sample reduced with potassium iodide and the acetylated reduced sample. Oxidized products were separated by preparative thin layer chromatography on silica gel and characterized by selective detection and by infrared spectrometry of the fractions. The oxidation products consisted of hydroperoxido butyl oleate, substituted hydroperoxides, mono- and disubstituted monomeric derivatives and a small amount of oligomers.

  11. Fission product behaviour in the primary circuit of an HTR

    International Nuclear Information System (INIS)

    Decken, C.B. von der; Iniotakis, N.

    1981-01-01

    The knowledge of fission product behaviour in the primary circuit of a High Temperature Reactor (HTR) is an essential requirement for the estimations of the availability of the reactor plant in normal operation, of the hazards to personnel during inspection and repair and of the potential danger to the environment from severe accidents. On the basis of the theoretical and experimental results obtained at the ''Institute for Reactor Components'' of the KFA Juelich /1/,/2/ the transport- and deposition behaviour of the fission- and activation products in the primary circuit of the PNP-500 reference plant has been investigated thoroughly. Special work had been done to quantify the uncertainties of the investigations and to calculate or estimate the dose rate level at different components of the primary cooling circuit. The contamination and the dose rate level in the inspection gap in the reactor pressure vessel is discussed in detail. For these investigations in particular the surface structure and the composition of the material, the chemical state of the fission products in the cooling gas, the composition of the cooling gas and the influence of dust on the transport- and deposition behaviour of the fission products have been taken into account. The investigations have been limited to the nuclides Ag-110m; Cs-134 and Cs-137

  12. Towards 250 m mapping of terrestrial primary productivity over Canada

    Science.gov (United States)

    Gonsamo, A.; Chen, J. M.

    2011-12-01

    Terrestrial ecosystems are an important part of the climate and global change systems. Their role in climate change and in the global carbon cycle is yet to be well understood. Dataset from satellite earth observation, coupled with numerical models provide the unique tools for monitoring the spatial and temporal dynamics of territorial carbon cycle. The Boreal Ecosystems Productivity Simulator (BEPS) is a remote sensing based approach to quantifying the terrestrial carbon cycle by that gross and net primary productivity (GPP and NPP) and terrestrial carbon sinks and sources expressed as net ecosystem productivity (NEP). We have currently implemented a scheme to map the GPP, NPP and NEP at 250 m for first time over Canada using BEPS model. This is supplemented by improved mapping of land cover and leaf area index (LAI) at 250 m over Canada from MODIS satellite dataset. The results from BEPS are compared with MODIS GPP product and further evaluated with estimated LAI from various sources to evaluate if the results capture the trend in amount of photosynthetic biomass distributions. Final evaluation will be to validate both BEPS and MODIS primary productivity estimates over the Fluxnet sites over Canada. The primary evaluation indicate that BEPS GPP estimates capture the over storey LAI variations over Canada very well compared to MODIS GPP estimates. There is a large offset of MODIS GPP, over-estimating the lower GPP value compared to BEPS GPP estimates. These variations will further be validated based on the measured values from the Fluxnet tower measurements over Canadian. The high resolution GPP (NPP) products at 250 m will further be used to scale the outputs between different ecosystem productivity models, in our case the Canadian carbon budget model of Canadian forest sector CBM-CFS) and the Integrated Terrestrial Ecosystem Carbon model (InTEC).

  13. Primary production in the Delta: Then and now

    Science.gov (United States)

    Cloern, James E.; Robinson, April; Richey, Amy; Grenier, Letitia; Grossinger, Robin; Boyer, Katharyn E.; Burau, Jon; Canuel, Elizabeth A.; DeGeorge, John F.; Drexler, Judith Z.; Enright, Chris; Howe, Emily R.; Kneib, Ronald; Mueller-Solger, Anke; Naiman, Robert J.; Pinckney, James L.; Safran, Samuel M.; Schoellhamer, David H.; Simenstad, Charles A.

    2016-01-01

    To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850). Here we describe an approach for using these metrics of land use change to: (1) produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2) convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3) use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

  14. Evaluation of Organic Proxies for Quantifying Past Primary Productivity

    Science.gov (United States)

    Raja, M.; Rosell-Melé, A.; Galbraith, E.

    2017-12-01

    Ocean primary productivity is a key element of the marine carbon cycle. However, its quantitative reconstruction in the past relies on the use of biogeochemical models as the available proxy approaches are qualitative at best. Here, we present an approach that evaluates the use of phytoplanktonic biomarkers (i.e. chlorins and alkenones) as quantitative proxies to reconstruct past changes in marine productivity. We compare biomarkers contents in a global suite of core-top sediments to sea-surface chlorophyll-a abundance estimated by satellites over the last 20 years, and the results are compared to total organic carbon (TOC). We also assess satellite data and detect satellite limitations and biases due to the complexity of optical properties and the actual defined algorithms. Our findings show that sedimentary chlorins can be used to track total sea-surface chlorophyll-a abundance as an indicator for past primary productivity. However, degradation processes restrict the application of this proxy to concentrations below a threshold value (1µg/g). Below this threshold, chlorins are a useful tool to identify reducing conditions when used as part of a multiproxy approach to assess redox sedimentary conditions (e.g. using Re, U). This is based on the link between anoxic/disoxic conditions and the flux of organic matter from the sea-surface to the sediments. We also show that TOC is less accurate than chlorins for estimating sea-surface chlorophyll-a due to the contribution of terrigenous organic matter, and the different degradation pathways of all organic compounds that TOC includes. Alkenones concentration also relates to primary productivity, but they are constrained by different processes in different regions. In conclusion, as lons as specific constraints are taken into account, our study evaluates the use of chlorins and alkenones as quantitative proxies of past primary productivity, with more accuracy than by using TOC.

  15. Primary Production in the Delta: Then and Now

    Directory of Open Access Journals (Sweden)

    James E. Cloern

    2016-10-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss3art1To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850. Here we describe an approach for using these metrics of land use change to: (1 produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2 convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3 use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

  16. Continuous-flow oxidative cyanation of primary and secondary amines using singlet oxygen.

    Science.gov (United States)

    Ushakov, Dmitry B; Gilmore, Kerry; Kopetzki, Daniel; McQuade, D Tyler; Seeberger, Peter H

    2014-01-07

    Primary and secondary amines can be rapidly and quantitatively oxidized to the corresponding imines by singlet oxygen. This reactive form of oxygen was produced using a variable-temperature continuous-flow LED-photoreactor with a catalytic amount of tetraphenylporphyrin as the sensitizer. α-Aminonitriles were obtained in good to excellent yields when trimethylsilyl cyanide served as an in situ imine trap. At 25°C, primary amines were found to undergo oxidative coupling prior to cyanide addition and yielded secondary α-aminonitriles. Primary α-aminonitriles were synthesized from the corresponding primary amines for the first time, by an oxidative Strecker reaction at -50 °C. This atom-economic and protecting-group-free pathway provides a route to racemic amino acids, which was exemplified by the synthesis of tert-leucine hydrochloride from neopentylamine. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Corrosion products behaviour under VVER primary coolant conditions

    International Nuclear Information System (INIS)

    Grygar, T.; Zmitko, M.

    2002-01-01

    The aim of this work was to collect data on thermodynamic stability of Cr, Fe, and Ni oxides, mechanisms of hydrothermal corrosion of stainless steels and to compare the real observation with the theory. We found that the electrochemical potential and pH in PWR and VVER are close to the thermodynamic boundary between two fields of stable spinel type oxides. The ways of degradation of the passivating layers due to changes in water chemistry were considered and PWR and VVER systems were found to be potentially endangered by reductive attack. In certain VVER systems the characteristics of the passivating layer on steels and also concentration of soluble corrosion products seem to be in contradiction with the theoretical expectations. (author)

  18. HANPP Collection: Human Appropriation of Net Primary Productivity (HANPP) by Country and Product

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Human Appropriation of Net Primary Productivity (HANPP) portion of the HANPP Collection represents a digital map of human appropriation of net...

  19. Cholesterol oxidation products and their biological importance

    DEFF Research Database (Denmark)

    Kulig, Waldemar; Cwiklik, Lukasz; Jurkiewicz, Piotr

    2016-01-01

    The main biological cause of oxysterols is the oxidation of cholesterol. They differ from cholesterol by the presence of additional polar groups that are typically hydroxyl, keto, hydroperoxy, epoxy, or carboxyl moieties. Under typical conditions, oxysterol concentration is maintained at a very low...... and precisely regulated level, with an excess of cholesterol. Like cholesterol, many oxysterols are hydrophobic and hence confined to cell membranes. However, small chemical differences between the sterols can significantly affect how they interact with other membrane components, and this in turn can have...

  20. Fission and corrosion products behavior in primary circuits of LMFBR's

    International Nuclear Information System (INIS)

    Feuerstein, H.; Thorley, A.W.

    1987-08-01

    Most of the 20 presented papers report items belonging to more than one session. The equipment results of primary circuits of LMFBR's relative to corrosion and fission products, release and chemistry of fuel, measurement techniques and analytical procedures of sodium sampling, difficulties with radionuclides and particles, reactor experiences with EBR-II, FFTF, BR10, BOR60, BN350, BN600, JOYO, and KNK-II, DFR, PFR, RAPSODIE, PHENIX, and SUPERPHENIX, and at least the verification of codes for calculation models of radioactive products accumulation and distribution are described. All 20 papers presented at the meeting are separately indexed in the database. (DG)

  1. Variations of Terrestrial Net Primary Productivity in East Asia

    Directory of Open Access Journals (Sweden)

    Fangmin Zhang

    2012-01-01

    Full Text Available Due to the heterogeneity and complexity of terrestrial ecosystems of East Asia, a better understanding of relationships between climate change and net primary productivity (NPP distribution is important to predict future carbon dynamics. The objective of this study is to analyze the temporal-spatial patterns of NPP in East Asia (10°S - 55°N, 60 - 155°E from 1982 to 2006 using the process-based Boreal Ecosystem Productivity Simulator (BEPS model. Prior to the regional simulation, the annual simulated NPP was validated using field observed NPP demonstrating the ability of BEPS to simulate NPP in different ecosystems of East Asia.

  2. Regulation of primary productivity rate in the equatorial Pacific

    International Nuclear Information System (INIS)

    Barber, R.T.; Chavez, F.P.

    1991-01-01

    Analysis of the Chl-specific rate of primary productivity (P B ) as a function of subsurface nutrient concentration at >300 equatorial stations provides an answer to the question: What processes regulate primary productivity rate in the high-nutrient, low-chlorophyll waters of the equatorial Pacific? In the western Pacific where there is a gradient in 60-m [NO 3 ] from 0 to ∼12 μM, the productivity rate is a linear function of nutrient concentration; in the eastern Pacific where the gradient is from 12 to 28 μM, the productivity rate is independent of nutrient concentration and limited to ∼36 mg C(mg Chl) -1 d -1 , or a mean euphotic zone C-specific growth rate (μ) of 0.47 d -1 . However, rates downstream of the Galapagos Islands are not limited; they are 46.4 mg C(mg Chl) -1 d -1 and μ = 0.57 d -1 , very close to the predicted nutrient-regulated rates in the absence of other limitation. This pattern of rate regulation can be accounted for by a combination of eolian Fe, subsurface nutrients, and sedimentary Fe derived from the Galapagos platform. In the low-nutrient western Pacific the eolian supply of Fe is adequate to allow productivity rate to be set by subsurface nutrient concentration. In the nutrient-rich easter equatorial region eolian Fe is inadequate to support productivity rates proportional to the higher nutrient concentrations, so in this region eolian Fe is rate limiting. Around the Galapagos Islands productivity rates reach levels consistent with nutrient concentrations; sedimentary Fe from the Galapagos platform seems adequate to support increased nutrient-regulated productivity rates in this region

  3. Production and characterization of quality gadolinium oxide nanoparticles

    International Nuclear Information System (INIS)

    Hazarika, Samiran; Mohanta, Dambarudhar

    2013-01-01

    Rare earth system Gadolinium (Gd), in either pure form or oxide form, is highly stable against environmental attack. It has immense potential as a contrast agent in magnetic resonance imaging (MRI) devices. Being mechanically and thermally stable it is always difficult to obtain Gd 2 O 3 nanopowders directly from its bulk counterpart using conventional top-down approach. Recently, we have reported production of Gd 2 O 3 nanopowders by first converting bulk Gd 2 O 3 into a nitrate compound and subsequently reduced into a hydroxide product and finally to the oxide product (nanopowder form)

  4. Artifacts Generated During Azoalkane Peroxy Radical Oxidative Stress Testing of Pharmaceuticals Containing Primary and Secondary Amines.

    Science.gov (United States)

    Nefliu, Marcela; Zelesky, Todd; Jansen, Patrick; Sluggett, Gregory W; Foti, Christopher; Baertschi, Steven W; Harmon, Paul A

    2015-12-01

    We report artifactual degradation of pharmaceutical compounds containing primary and secondary amines during peroxy radical-mediated oxidative stress carried out using azoalkane initiators. Two degradation products were detected when model drug compounds dissolved in methanol/water were heated to 40°C with radical initiators such as 2,2'-azobis(2-methylpropionitrile) (AIBN). The primary artifact was identified as an α-aminonitrile generated from the reaction of the amine group of the model drug with formaldehyde and hydrogen cyanide, generated as byproducts of the stress reaction. A minor artifact was generated from the reaction between the amine group and isocyanic acid, also a byproduct of the stress reaction. We report the effects of pH, initiator/drug molar ratio, and type of azoalkane initiator on the formation of these artifacts. Mass spectrometry and nuclear magnetic resonance were used for structure elucidation, whereas mechanistic studies, including stable isotope labeling experiments, cyanide analysis, and experiments exploring the effects of butylated hydroxyanisole addition, were employed to support the degradation pathways. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  5. Discussion on the differences between epigenetic oxidized and primary red beds

    International Nuclear Information System (INIS)

    Chen Xiaolin; Fang Xiheng; Sun Ye; Pang Yaqing; Guo Qingyin

    2008-01-01

    The red oxidation zone may be formed in the process of the interlayer oxidation. If the original gray beds formed in the moist palaeoclimatic condition and became red in oxidation, it is easy to distinguish this red oxidization zone from the original red beds. Gray sandstone sandwiched by red mudstone can be formed partially in the arid-semiarid condition. If this gray sandstone was oxidized to be red in color, almost all the strata would be red in cross section, and then it will be difficult to distinguish these red strata from the original red beds. If they are regarded as original red beds, we maybe lose the favorable opportunity to find uranium deposit. This paper presents a case study of Yaojia Formation, Upper Cretaceous in the southwestern part of Songliao Basin. Although the palaeoelimatic condition was arid-semiarid, the gray sandstones of Yaojia Formation in Qianjiadian Sag and its adjacent areas have obvious characteristics of primary depositional origin, and part of them may be formed by epigenetic reduction. The gray sandstone has formed red interlayer oxidation zone after being oxidized and it is just the red interlayer oxidation zone which controls the uranium mineralization in Qianjiadian uranium deposit. By careful contrast and analysis, identification marks of red epigenetic oxidation beds have be established, which can effectively help the distinguishing of epigenetic oxidized red beds from original red beds and extends prospecting idea. (authors)

  6. Study of cryoprotectors effect on oxidation processes at storage of frozen halffinished products

    Directory of Open Access Journals (Sweden)

    O. Glushkov

    2016-12-01

    Full Text Available The publication presents data on the effect of polysaccharides as cryoprotectants on changes of the lipid fraction of quick-frozen semi-finished products during storage. Since the structure of minced systems is formed as a result of the destruction of the native structure of the meat and the formation of a new secondary structure, it is important to establish the effect of cryoprotectants on the key functional and technological properties of meat systems after freezing, and in the process of storage. Based on studies of the kinetics of the oxidation of fat and accumulation data on the accumulation of the primary and secondary products of oxidation inhibition of oxidative processes has been found.

  7. Hydrogen Production Costs of Various Primary Energy Sources

    International Nuclear Information System (INIS)

    Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

    2005-11-01

    Many studies on the economical aspects of hydrogen energy technologies have been conducted with the increase of the technical and socioeconomic importance of the hydrogen energy. However, there is still no research which evaluates the economy of hydrogen production from the primary energy sources in consideration of Korean situations. In this study, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations such as feedstock price, electricity rate, and load factor. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S. The present study focuses on the possible future technology scenario defined by NAS. The scenario assumes technological improvement that may be achieved if present research and development (R and D) programs are successful. The production costs by the coal and natural gas are 1.1 $/kgH 2 and 1.36 $/kgH 2 , respectively. However, the fossil fuels are susceptible to the price variation depending on the oil and the raw material prices, and the hydrogen production cost also depends on the carbon tax. The economic competitiveness of the renewable energy sources such as the wind, solar, and biomass are relatively low when compared with that of the other energy sources. The estimated hydrogen production costs from the renewable energy sources range from 2.35 $/kgH 2 to 6.03 $/kgH 2 . On the other hand, the production cost by nuclear energy is lower than that of natural gas or coal when the prices of the oil and soft coal are above $50/barrel and 138 $/ton, respectively. Taking into consideration the recent rapid increase of the oil and soft coal prices and the limited fossil resource, the nuclear-hydrogen option appears to be the most economical way in the future

  8. Regionally and seasonally differentiated primary production in the North Atlantic

    Science.gov (United States)

    Sathyendranath, Shubha; Longhurst, Alan; Caverhill, Carla M.; Platt, Trevor

    1995-10-01

    A bio-geochemical classification of the N. Atlantic Basin is presented according to which the basin is first divided into four primary algal domains: Polar, West-Wind, Trades and Coastal. These are in turn sub-divided into smaller provinces. The classification is based on differences in the physical environment which are likely to influence regional algal dynamics. The seasonally-differentiated parameters of the photosynthesis-light curve ( P-I curve) and parameters that define the vertical structure in chlorophyll profile are then established for each province, based on an analysis of an archive of over 6000 chlorophyll profiles, and over 1800 P-I curves. These are then combined with satellite-derived chlorophyll data for the N. Atlantic, and information on cloud cover, to compute primary production at the annual scale. using a model that computes spectral transmission of light underwater, and spectral, photosynthetic response of phytoplankton to available light. The results are compared with earlier, satellite-derived, estimates of basin-scale primary production.

  9. Global net primary production and heterotrophic respiration for 1987

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, R.E. Jr.; Piper, S.C.; Nemani, R. [Univ. of Montana, Missoula, MT (United States)]|[Scripps Institute of Oceanography, La Jolla, CA (United States)] [and others

    1995-06-01

    An ecosystem process model, BIOME-BGC, was parameterized and used to simulate the actual net primary production and heterotrophic respiration using daily climatic data, land cover type, leaf area index gridded to 1{degree} latitude by 1{degree} longitude grid cells for the year 1987. Global net primary production was 52 Pg C. These estimates were validated directly by two different methods. First, the grid cells were aggregated and used as inputs to a 3D atmospheric transport model, to compare CO{sub 2} station data with predictions. We simulated the intra-annual variation of atmospheric CO{sub 2} well for the northern hemisphere, but not for the southern hemisphere. Second, we calculated the net {sup 13}C uptake of vegetation, which is a function of water use efficiency. The {sup 13}C/{sup 12}C ratios agreed with measured data, indicating a strong limitation of global primary processes by the hydrologic cycle, especially precipitation. These are different from other global carbon models as we can simulate the year-to-year variation of climate, including El Nino, on the global carbon cycle.

  10. Solubility of simulated PWR primary circuit corrosion products

    International Nuclear Information System (INIS)

    Kunig, R.H.; Sandler, Y.L.

    1986-08-01

    The solubility behavior of non-stoichiometric nickel ferrites, nickel-cobalt ferrites, and magnetite, as model substances for the corrosion products (''crud'') formed in nuclear pressurized water reactors, was studied in a flow system in aqueous solutions of lithium hydroxide, boric acid, and hydrogen with pH, temperature, and hydrogen concentrations as parameters. Below the temperature region of 300 to 330 0 C, at hydrogen concentrations of 25 to 40 cm 3 /kg H 2 O as used during reactor operation, the solubility of nickel-cobalt ferrite is the same as that of Ni and Co/sub x/Fe/sub 3-x/O 4 (x 3 /kg of hydrogen, the equilibrium iron and nickel solubilities increase congruently down to about 100 0 C, in a manner consistent with the solubility of Fe 3 O 4 , but sharply decline at lower temperatures, apparently due to formation of a borated layer. A cooldown experiment on a time scale of a typical Westinghouse reactor shutdown, as well as static experiments carried out on various ferrite samples at 60 0 C show that after addition of oxygen or peroxide evolution of nickel (and possibly cobalt) above the equilibrium solubility in hydrogen depends on the presence of dissociation products prior to oxidation. Thermodynamic calculations of various reduction and oxidative decomposition reactions for stoichiometric and non-stoichiometric nickel ferrite and cobalt ferrite are presented. Their significance to evolutions of nickel and cobalt on reactor shutdown is discussed. 30 refs., 38 figs., 34 tabs

  11. Fact and Fiction of Nitrous Oxide Production By Nitrification

    Science.gov (United States)

    Stein, L. Y.; Kozlowski, J.; Stieglmeier, M.; Klotz, M. G.; Schleper, C.

    2014-12-01

    An accepted dogma in nitrification research is that ammonia-oxidizing bacteria (AOB) produce a modicum of nitrous oxide (N2O) during nitritation via incomplete oxidation of hydroxylamine, and substantially more at low oxygen concentrations via nitrifier denitrification.The nitrifier denitrification pathway involves the reduction of nitrite to N2O via nitric oxide and was thought to require activities of a copper-containing nitrite reductase (NirK) and nitric oxide reductase (NorB); inventory encoded in most, but not all AOB genome sequences. The discovery of nirK genes in ammonia-oxidizing Thaumarchaeota (AOA) resulted in a slew of publications stating that AOA must also perform nitrifier denitrification and, due to their high abundance, must control the majority of nitrification-linked N2O emissions. Prior to a publication by Stieglmeier et al. (2014), which definitively showed a lack of nitrifier denitrification by two axenic AOA cultures, other researchers relied on enrichment cultures, negative data, and heavy inferencing without direct demonstration of either a functional pathway or involvement of specific genes or enzymes. AOA genomes lack recognizable nitric oxide reductases and thermophilic AOA also lack nirK genes. Physiological and microrespirometry experiments with axenic AOB and AOA cultures allowed us to demonstrate that: 1) AOB produce N2O via nitrifier denitrification even though some lack annotated nirK and/or norB genes; 2) nitrifier denitrification by AOB is reliant on nitric oxide but ammonia oxidation is not; 3) ammonia oxidation by AOA is reliant on production of nitric oxide; 4) AOA are incapable of generating N2O via nitrifier denitrification; 5) N2O production by AOA is from chemical interactions between NO and media components, most likely not by enzyme activity. Our results reveal operation of different N oxide transformation pathways in AOB and AOA governed by different environmental controls and involving different mechanisms of N2O

  12. Molecular biology in studies of oceanic primary production

    International Nuclear Information System (INIS)

    LaRoche, J.; Falkowski, P.G.; Geider, R.

    1992-01-01

    Remote sensing and the use of moored in situ instrumentation has greatly improved our ability to measure phytoplankton chlorophyll and photosynthesis on global scales with high temporal resolution. However, the interpretation of these measurements and their significance with respect to the biogeochemical cycling of carbon relies on their relationship with physiological and biochemical processes in phytoplankton. For example, the use of satellite images of surface chlorophyll to estimate primary production is often based on the functional relationship between photosynthesis and irradiance. A variety of environmental factors such as light, temperature, nutrient availability affect the photosynthesis/irradiance (P vs I) relationship in phytoplankton. We present three examples showing how molecular biology can be used to provide basic insight into the factors controlling primary productivity at three different levels of complexity: 1. Studies of light intensity regulation in unicellular alga show how molecular biology can help understand the processing of environmental cues leading to the regulation of photosynthetic gene expression. 2. Probing of the photosynthetic apparatus using molecular techniques can be used to test existing mechanistic models derived from the interpretation of physiological and biophysical measurements. 3. Exploratory work on the expression of specific proteins during nutrient-limited growth of phytoplankton may lead to the identification and production of molecular probes for field studies

  13. Oxidation of primary amines to oximes with molecular oxygen using 1,1-diphenyl-2-picrylhydrazyl and WO3/Al2O3 as catalysts.

    Science.gov (United States)

    Suzuki, Ken; Watanabe, Tomonari; Murahashi, Shun-Ichi

    2013-03-15

    The oxidative transformation of primary amines to their corresponding oximes proceeds with high efficiency under molecular oxygen diluted with molecular nitrogen (O2/N2 = 7/93 v/v, 5 MPa) in the presence of the catalysts 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tungusten oxide/alumina (WO3/Al2O3). The method is environmentally benign, because the reaction requires only molecular oxygen as the terminal oxidant and gives water as a side product. Various alicyclic amines and aliphatic amines can be converted to their corresponding oximes in excellent yields. It is noteworthy that the oxidative transformation of primary amines proceeds chemoselectively in the presence of other functional groups. The key step of the present oxidation is a fast electron transfer from the primary amine to DPPH followed by proton transfer to give the α-aminoalkyl radical intermediate, which undergoes reaction with molecular oxygen and hydrogen abstraction to give α-aminoalkyl hydroperoxide. Subsequent reaction of the peroxide with WO3/Al2O3 gives oximes. The aerobic oxidation of secondary amines gives the corresponding nitrones. Aerobic oxidative transformation of cyclohexylamines to cyclohexanone oximes is important as a method for industrial production of ε-caprolactam, a raw material for Nylon 6.

  14. Patterns of primary production in the Red Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Qurban, M.A.; Wafar, M.; Jyothibabu, R.; Manikandan, K.P.

    for bio- phic stations occupied in e Indian Ocean (source - et al., 1995), remotely-sensed (CZCS) chlorophyll data were used to make deductions on rates of primary production at basin-scale. The conclusion consistently arrived at from all earlier studies... acquired along the axis of the basin in the 2013 cruise, Wafar et al. (2016a) identified alternating zonal currents at six locations – 18–18.5°N, 19–20.5°N, 22°N, 24°N, 24.5°N and 26°N - and concluded that they represent three successive anticyclonic cells...

  15. A Highly Practical Copper(I)/TEMPO Catalyst System for Chemoselective Aerobic Oxidation of Primary Alcohols

    Science.gov (United States)

    Hoover, Jessica M.; Stahl, Shannon S.

    2011-01-01

    Aerobic oxidation reactions have been the focus of considerable attention, but their use in mainstream organic chemistry has been constrained by limitations in their synthetic scope and by practical factors, such as the use of pure O2 as the oxidant or complex catalyst synthesis. Here, we report a new (bpy)CuI/TEMPO catalyst system that enables efficient and selective aerobic oxidation of a broad range of primary alcohols, including allylic, benzylic and aliphatic derivatives, to the corresponding aldehydes using readily available reagents, at room temperature with ambient air as the oxidant. The catalyst system is compatible with a wide range of functional groups and the high selectivity for 1° alcohols enables selective oxidation of diols that lack protecting groups. PMID:21861488

  16. Trophic transfer potential of aluminium oxide nanoparticles using representative primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia)

    Energy Technology Data Exchange (ETDEWEB)

    Pakrashi, Sunandan; Dalai, Swayamprava; Chandrasekaran, Natarajan; Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com

    2014-07-01

    Highlights: • Trophic transfer of alumina nanoparticles using Chlorella ellipsoides and Ceriodaphnia dubia. • Subtle alterations in the feeding behaviour of the daphnids. • Disruption the energy flow through the food chain. • Transmission electron microscopy validated the disrupted feeding behaviour. - Abstract: The transfer of nanoparticles through the food chain can lead to bioaccumulation and biomagnification resulting in a long term negative impact on the ecosystem functions. The primary objective of this study was evaluation of aluminium oxide nanoparticles transfer from primary producers to primary consumers. A simple set up consisting of a primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia) was used. Here, C. ellipsoides were exposed to the varying concentrations of the nanoparticles ranging from 20 to 120 μg/mL (196 to 1176 μM) for 48 h and the infested algal cells were used as the feed to C. dubia. The bioaccumulation of the nanoparticles into the daphnids was noted and the biomagnification factors were computed. The exposure was noted to cause subtle alterations in the feeding behaviour of the daphnids. This might have long term consequences in the energy flow through the food chain. The reproductive behaviour of the daphnids remained unaffected upon exposure to nanoparticle infested algal feed. Distinct observations at ultra-structural scale using transmission electron microscopy provided visual evidences for the disrupted feeding behaviour upon exposure to nanoparticle treated algae. Internalization of nanoparticle like inclusion bodies in the intracellular space of algae was also detected. The findings were further substantiated by a detailed analysis of hydrodynamic stability, bioavailability and dissolution of ions from the nanoparticles over the exposure period. Altogether, the study brings out the first of its kind of observation of trophic transfer potential/behaviour of aluminium oxide nanoparticles and

  17. Trophic transfer potential of aluminium oxide nanoparticles using representative primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia)

    International Nuclear Information System (INIS)

    Pakrashi, Sunandan; Dalai, Swayamprava; Chandrasekaran, Natarajan; Mukherjee, Amitava

    2014-01-01

    Highlights: • Trophic transfer of alumina nanoparticles using Chlorella ellipsoides and Ceriodaphnia dubia. • Subtle alterations in the feeding behaviour of the daphnids. • Disruption the energy flow through the food chain. • Transmission electron microscopy validated the disrupted feeding behaviour. - Abstract: The transfer of nanoparticles through the food chain can lead to bioaccumulation and biomagnification resulting in a long term negative impact on the ecosystem functions. The primary objective of this study was evaluation of aluminium oxide nanoparticles transfer from primary producers to primary consumers. A simple set up consisting of a primary producer (Chlorella ellipsoides) and a primary consumer (Ceriodaphnia dubia) was used. Here, C. ellipsoides were exposed to the varying concentrations of the nanoparticles ranging from 20 to 120 μg/mL (196 to 1176 μM) for 48 h and the infested algal cells were used as the feed to C. dubia. The bioaccumulation of the nanoparticles into the daphnids was noted and the biomagnification factors were computed. The exposure was noted to cause subtle alterations in the feeding behaviour of the daphnids. This might have long term consequences in the energy flow through the food chain. The reproductive behaviour of the daphnids remained unaffected upon exposure to nanoparticle infested algal feed. Distinct observations at ultra-structural scale using transmission electron microscopy provided visual evidences for the disrupted feeding behaviour upon exposure to nanoparticle treated algae. Internalization of nanoparticle like inclusion bodies in the intracellular space of algae was also detected. The findings were further substantiated by a detailed analysis of hydrodynamic stability, bioavailability and dissolution of ions from the nanoparticles over the exposure period. Altogether, the study brings out the first of its kind of observation of trophic transfer potential/behaviour of aluminium oxide nanoparticles and

  18. Software sensor for primary metabolite production case of alcoholic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Roux, G.; Dahhou, B.; Queinnec, I. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France)]|[Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France); Goma, G. [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France)

    1995-12-31

    This paper investigate the application of an observer for state and parameter estimation to batch, continuous and fed batch fermentations for alcohol production taken as model for a primary metabolite production. This observer is provided to palliate the lack of suitable sensors for on-line biomass and ethanol concentrations measurements and to estimate the time varying specific growth rate. Estimates are obtained from an interlaced structure filter based on a `modified extended Kalman filter` by using on-line measurements of carbon dioxide outflow rate and substrate concentration. The filter algorithm was tested during batch, continuous and fed batch fermentation processes. The filter behaviour observed in the experiments gives good results with an agreement theory/practice. (authors) 18 refs.

  19. Inorganic carbon addition stimulates snow algae primary productivity

    Science.gov (United States)

    Hamilton, T. L.; Havig, J. R.

    2017-12-01

    Earth has experienced glacial/interglacial oscillations throughout its history. Today over 15 million square kilometers (5.8 million square miles) of Earth's land surface is covered in ice including glaciers, ice caps, and the ice sheets of Greenland and Antarctica, most of which are retreating as a consequence of increased atmospheric CO2. Glaciers are teeming with life and supraglacial snow and ice surfaces are often red due to blooms of photoautotrophic algae. Recent evidence suggests the red pigmentation, secondary carotenoids produced in part to thrive under high irradiation, lowers albedo and accelerates melt. However, there are relatively few studies that report the productivity of snow algae communities and the parameters that constrain their growth on snow and ice surfaces. Here, we demonstrate that snow algae primary productivity can be stimulated by the addition of inorganic carbon. We found an increase in light-dependent carbon assimilation in snow algae microcosms amended with increasing amounts of inorganic carbon. Our snow algae communities were dominated by typical cosmopolitan snow algae species recovered from Alpine and Arctic environments. The climate feedbacks necessary to enter and exit glacial/interglacial oscillations are poorly understood. Evidence and models agree that global Snowball events are accompanied by changes in atmospheric CO2 with increasing CO2 necessary for entering periods of interglacial time. Our results demonstrate a positive feedback between increased CO2 and snow algal productivity and presumably growth. With the recent call for bio-albedo effects to be considered in climate models, our results underscore the need for robust climate models to include feedbacks between supraglacial primary productivity, albedo, and atmospheric CO2.

  20. Application of Primary Abatement Technology for Reduction of N2O Emmision in Petrokemija Nitric Acid Production

    Directory of Open Access Journals (Sweden)

    Ćosić, L.

    2013-01-01

    Full Text Available Industrial nitric acid production by oxidation of gaseous ammonia with Ostwald procedure produces an unwanted by-product – colorless nitrous oxide, N2O. As emission of N2O represents a very serious problem due of its huge contribution to global warming, certain measures focused on its maximum reduction should be undertaken. Minimization of N2O emission in nitric acid production can be achieved in different parts of the process flow, depending on the applied available technologies. For the abatement of N2O emissions in Petrokemija's nitric acid production processes from the list of the best available technologies chosen were primary and secondary abatement technologies. The mentioned ensures reduction of N2O by use of improved selective heterogeneous catalysts in the step of gaseous ammonia oxidation. Precious metals in the shape of gauzes are used as selective heterogeneous catalyst in primary technology, while in the case of secondary technology the Fe2 O3 catalyst on Al2O3 support in the shape of spherical pellets is chosen. Shown is the application of primary technology for the abatement of N2O in both nitric acid production facilities and their comparison with classical heterogeneous catalyst and preparation for the installation of secondary selective catalyst. N2O emissions with the application of primary technology in both production facilities were reduced from 12 kg of N2O to 7 kg of N2O per ton of pure HNO3. With the primary reduction in N2O emissions the foundation was established for further reduction with the secondary technology to the final value of 0.7 kg of N2O per ton of pure HNO3, which represents mass concentration in the tail gas below 200 mg m-3 (at n. c.. With the applied technologies for the abatement of N2O emissions in Petrokemija's nitric acid production the future prescribed emission limit value will be satisfied.

  1. Electrochemical characterisation of solid oxide cell electrodes for hydrogen production

    DEFF Research Database (Denmark)

    Bernuy-Lopez, Carlos; Knibbe, Ruth; He, Zeming

    2011-01-01

    Oxygen electrodes and steam electrodes are designed and tested to develop improved solid oxide electrolysis cells for H2 production with the cell support on the oxygen electrode. The electrode performance is evaluated by impedance spectroscopy testing of symmetric cells at open circuit voltage (OCV...

  2. Modification of Casein by the Lipid Oxidation Product Malondialdehyde

    NARCIS (Netherlands)

    Adams, A.; Kimpe, de N.; Boekel, van T.

    2008-01-01

    The reaction of malondialdehyde with casein was studied in aqueous solution to evaluate the impact of this lipid oxidation product on food protein modification. By using multiresponse modeling, a kinetic model was developed for this reaction. The influence of temperature and pH on protein browning

  3. Fission product release by fuel oxidation after water ingress

    International Nuclear Information System (INIS)

    Schreiber.

    1990-01-01

    On the basis of data obtained by a literature search, a computer code has been established for the calculation of the degree of oxidation of the fuel in the damaged fuel particles, and hence of the fission product release as a function of the time period of steam ingress. (orig.) [de

  4. Controlling nitrous oxide emissions from grassland livestock production systems

    NARCIS (Netherlands)

    Oenema, O.; Gebauer, G.; Rodriguez, M.; Sapek, A.; Jarvis, S.C.; Corré, W.J.; Yamulki, S.

    1998-01-01

    There is growing awareness that grassland livestock production systems are major sources of nitrous oxide (N2O). Controlling these emissions requires a thorough understanding of all sources and controlling factors at the farm level. This paper examines the various controlling factors and proposes

  5. Bee products prevent agrichemical-induced oxidative damage in fish.

    Directory of Open Access Journals (Sweden)

    Daiane Ferreira

    Full Text Available In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™ and a group that was exposed to 0.88 mg L(-1 of TEB alone (corresponding to 16.6% of the 96-h LC50. We show that waterborne bee products, including royal jelly (RJ, honey (H, bee pollen (BP and propolis (P, reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD, catalase (CAT and glutathione-S-transferase (GST are increased.

  6. Bee products prevent agrichemical-induced oxidative damage in fish.

    Science.gov (United States)

    Ferreira, Daiane; Rocha, Helio Carlos; Kreutz, Luiz Carlos; Loro, Vania Lucia; Marqueze, Alessandra; Koakoski, Gessi; da Rosa, João Gabriel Santos; Gusso, Darlan; Oliveira, Thiago Acosta; de Abreu, Murilo Sander; Barcellos, Leonardo José Gil

    2013-01-01

    In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g) were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™) and a group that was exposed to 0.88 mg L(-1) of TEB alone (corresponding to 16.6% of the 96-h LC50). We show that waterborne bee products, including royal jelly (RJ), honey (H), bee pollen (BP) and propolis (P), reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) are increased.

  7. ARIES Oxide Production Program Annual Report - FY14

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, Evelyn A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dinehart, Steven Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-01

    A summary of the major accomplishments (September), milestones, financial summary, project performance and issues facing the ARIES Oxide Production Program at the close of FY14 is presented in this Executive Summary. Annual accomplishments are summarized in the body of the report.

  8. Size-dependent cytotoxicity of yttrium oxide nanoparticles on primary osteoblasts in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guoqiang, E-mail: zhougq1982@163.com; Li, Yunfei; Ma, Yanyan; Liu, Zhu; Cao, Lili; Wang, Da; Liu, Sudan; Xu, Wenshi; Wang, Wenying [Hebei University, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science (China)

    2016-05-15

    Yttrium oxide nanoparticles are an excellent host material for the rare earth metals and have high luminescence efficiency providing a potential application in photodynamic therapy and biological imaging. In this study, the effects of yttrium oxide nanoparticles with four different sizes were investigated using primary osteoblasts in vitro. The results demonstrated that the cytotoxicity generated by yttrium oxide nanoparticles depended on the particle size, and smaller particles possessed higher toxicological effects. For the purpose to elucidate the relationship between reactive oxygen species generation and cell damage, cytomembrane integrity, intracellular reactive oxygen species level, mitochondrial membrane potential, cell apoptosis rate, and activity of caspase-3 in cells were then measured. Increased reactive oxygen species level was also observed in a size-dependent way. Thus, our data demonstrated that exposure to yttrium oxide nanoparticles resulted in a size-dependent cytotoxicity in cultured primary osteoblasts, and reactive oxygen species generation should be one possible damage pathway for the toxicological effects produced by yttrium oxide particles. The results may provide useful information for more rational applications of yttrium oxide nanoparticles in the future.

  9. RAGE-Specific Inhibitor FPS-ZM1 Attenuates AGEs-Induced Neuroinflammation and Oxidative Stress in Rat Primary Microglia.

    Science.gov (United States)

    Shen, Chao; Ma, Yingjuan; Zeng, Ziling; Yin, Qingqing; Hong, Yan; Hou, Xunyao; Liu, Xueping

    2017-10-01

    Advanced glycation end products (AGEs) enhance microglial activation and intensify the inflammatory response and oxidative stress in the brain. This process may occur due to direct cytotoxicity or interacting with AGEs receptors (RAGE), which are expressed on the surface of microglia. FPS-ZM1 is a high-affinity but nontoxic RAGE-specific inhibitor that has been recently shown to attenuate the Aβ-induced inflammatory response by blocking the ligation of Aβ to RAGE. In this study, we further investigated the effect of FPS-ZM1 on the AGEs/RAGE interaction and downstream elevation of neuroinflammation and oxidative stress in primary microglia cells. The results suggested that FPS-ZM1 significantly suppressed AGEs-induced RAGE overexpression, RAGE-dependent microglial activation, nuclear translocation of nuclear factor kappaB p65 (NF-κB p65), and the expression of downstream inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), cyclooxygenase 2 (COX-2)/prostaglandin E2 (PGE2) and inducible nitric oxide synthase (iNOS)/nitric oxide (NO). Furthermore, FPS-ZM1 attenuated AGEs-stimulated NADPH oxidase (NOX) activation and reactive oxygen species (ROS) expression. Finally, FPS-ZM1 elevated the levels of transcription factors nuclear-factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1), as well as decreased antioxidant capacity and increased production of oxidative species. Our results suggest that FPS-ZM1 may be neuroprotective through attenuating microglial activation, oxidative stress and inflammation by blocking RAGE.

  10. Phytoplankton primary production in the world's estuarine-coastal ecosystems

    Science.gov (United States)

    Cloern, James E.; Foster, S.Q.; Kleckner, A.E.

    2014-01-01

    Estuaries are biogeochemical hot spots because they receive large inputs of nutrients and organic carbon from land and oceans to support high rates of metabolism and primary production. We synthesize published rates of annual phytoplankton primary production (APPP) in marine ecosystems influenced by connectivity to land – estuaries, bays, lagoons, fjords and inland seas. Review of the scientific literature produced a compilation of 1148 values of APPP derived from monthly incubation assays to measure carbon assimilation or oxygen production. The median value of median APPP measurements in 131 ecosystems is 185 and the mean is 252 g C m−2 yr−1, but the range is large: from −105 (net pelagic production in the Scheldt Estuary) to 1890 g C m−2 yr−1 (net phytoplankton production in Tamagawa Estuary). APPP varies up to 10-fold within ecosystems and 5-fold from year to year (but we only found eight APPP series longer than a decade so our knowledge of decadal-scale variability is limited). We use studies of individual places to build a conceptual model that integrates the mechanisms generating this large variability: nutrient supply, light limitation by turbidity, grazing by consumers, and physical processes (river inflow, ocean exchange, and inputs of heat, light and wind energy). We consider method as another source of variability because the compilation includes values derived from widely differing protocols. A simulation model shows that different methods reported in the literature can yield up to 3-fold variability depending on incubation protocols and methods for integrating measured rates over time and depth. Although attempts have been made to upscale measures of estuarine-coastal APPP, the empirical record is inadequate for yielding reliable global estimates. The record is deficient in three ways. First, it is highly biased by the large number of measurements made in northern Europe (particularly the Baltic region) and North America. Of the 1148

  11. Oxidative stress and antioxidant status in primary bone and soft tissue sarcoma

    International Nuclear Information System (INIS)

    Nathan, Fatima M; Singh, Vivek A; Dhanoa, Amreeta; Palanisamy, Uma D

    2011-01-01

    Oxidative stress is characterised by an increased level of reactive oxygen species (ROS) that disrupts the intracellular reduction-oxidation (redox) balance and has been implicated in various diseases including cancer. Malignant tumors of connective tissue or sarcomas account for approximately 1% of all cancer diagnoses in adults and around 15% of paediatric malignancies per annum. There exists no information on the alterations of oxidant/antioxidant status of sarcoma patients in literature. This study was aimed to determine the levels of oxidative stress and antioxidant defence in patients with primary bone and soft tissue sarcoma and to investigate if there exists any significant differences in these levels between both the sarcomas. The study cohort consisted of 94 subjects; 20 soft tissue sarcoma, 27 primary bone sarcoma and 47 healthy controls. Malondialdehyde (MDA) and protein carbonyls were determined to assess their oxidative stress levels while antioxidant status was evaluated using catalase (CAT), superoxide dismutase (SOD), thiols and trolox equivalent antioxidant capacity (TEAC). Sarcoma patients showed significant increase in plasma and urinary MDA and serum protein carbonyl levels (p < 0.05) while significant decreases were noted in TEAC, thiols, CAT and SOD levels (p < 0.05). No significant difference in oxidative damage was noted between both the sarcomas (p > 0.05). In conclusion, an increase in oxidative stress and decrease in antioxidant status is observed in both primary bone and soft tissue sarcomas with a similar extent of damage. This study offers the basis for further work on whether the manipulation of redox balance in patients with sarcoma represents a useful approach in the design of future therapies for bone disease

  12. Bilirubin and its oxidation products damage brain white matter

    Science.gov (United States)

    Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

    2014-01-01

    Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

  13. Hydrogen Production Costs of Various Primary Energy Sources

    International Nuclear Information System (INIS)

    Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

    2005-01-01

    The limited resource and environmental impacts of fossil fuels are becoming more and more serious problems in the world. Consequently, hydrogen is in the limelight as a future alternative energy due to its clean combustion and inexhaustibility and a transition from the traditional fossil fuel system to a hydrogen-based energy system is under considerations. Several countries are already gearing the industries to the hydrogen economy to cope with the limitations of the current fossil fuels. Unfortunately, hydrogen has to be chemically separated from the hydrogen compounds in nature such as water by using some energy sources. In this paper, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S

  14. Monitoring residue in animals and primary products of animal origin

    Directory of Open Access Journals (Sweden)

    Janković Saša

    2008-01-01

    Full Text Available The objective of control and systematic monitoring of residue is to secure, by the examination of a corresponding number of samples, the efficient monitoring of the residue level in tissues and organs of animals, as well as in primary products of animal origin. This creates possibilities for the timely taking of measures toward the securing of food hygiene of animal origin and the protection of public health. Residue can be a consequence of the inadequate use of medicines in veterinary medicine and pesticides in agriculture and veterinary medicine, as well as the polluting of the environment with toxic elements, dioxins, polychlorinated biphenyls, and others. Residue is being monitored in Serbia since 1972, and in 2004, national monitoring was brought to the level of EU countries through significant investments by the Ministry of Agriculture, Forestry and Water Management. This is also evident in the EU directives which permit exports of all kinds of meat and primary products of animal origin, covered by the Residue Monitoring Program. The program of systematic examinations of residue has been coordinated with the requirements of the European Union, both according to the type of examined substance, as well as according to the number of samples and the applied analytical techniques. In addition to the development of methods and the including of new harmful substances into the monitoring programme, it is also necessary to coordinate the national regulations that define the maximum permitted quantities of certain medicines and contaminants with the EU regulations, in order to protect the health of consumers as efficiently as possible, and for the country to take equal part in international trade.

  15. Satellite Driven Estimation of Primary Productivity of Agroecosystems in India

    Science.gov (United States)

    Patel, N. R.; Dadhwal, V. K.; Agrawal, S.; Saha, S. K.

    2011-08-01

    Earth observation driven ecosystem modeling have played a major role in estimation of carbon budget components such as gross primary productivity (GPP) and net primary production (NPP) over terrestrial ecosystems, including agriculture. The present study therefore evaluate satellite-driven vegetation photosynthesis (VPM) model for GPP estimation over agro-ecosystems in India by using time series of the Normalized Difference Vegetation Index (NDVI) from SPOT-VEGETATION, cloud cover observation from MODIS, coarse-grid C3/C4 crop fraction and decadal grided databases of maximum and minimum temperatures. Parameterization of VPM parameters e.g. maximum light use efficiency (ɛ*) and Tscalar was done based on eddy-covariance measurements and literature survey. Incorporation of C3/C4 crop fraction is a modification to commonly used constant maximum LUE. Modeling results from VPM captured very well the geographical pattern of GPP and NPP over cropland in India. Well managed agro-ecosystems in Trans-Gangetic and upper Indo-Gangetic plains had the highest magnitude of GPP with peak GPP during kharif occurs in sugarcane-wheat system (western UP) and it occurs in rice-wheat system (Punjab) during Rabi season. Overall, croplands in these plains had more annual GPP (> 1000 g C m-2) and NPP (> 600 g C m-2) due to input-intensive cultivation. Desertic tracts of western Rajasthan showed the least GPP and NPP values. Country-level contribution of croplands to national GPP and NPP amounts to1.34 Pg C year-1 and 0.859 Pg C year-1, respectively. Modeled estimates of cropland NPP agrees well with ground-based estimates for north-western India (R2 = 0.63 and RMSE = 108 g C m-2). Future research will focus on evaluating the VPM model with medium resolution sensors such as AWiFS and MODIS for rice-wheat system and validating with eddy-covariance measurements.

  16. Unsaponifiable fraction isolated from grape (Vitis vinifera L.) seed oil attenuates oxidative and inflammatory responses in human primary monocytes.

    Science.gov (United States)

    Millan-Linares, Maria C; Bermudez, Beatriz; Martin, Maria E; Muñoz, Ernesto; Abia, Rocio; Millan, Francisco; Muriana, Francisco J G; Montserrat-de la Paz, Sergio

    2018-04-25

    Grape (Vitis vinifera L.) seed has well-known potential for production of oil as a byproduct of winemaking and is a rich source of bioactive compounds. Herein, we report that the unsaponifiable fraction (UF) isolated from grape seed oil (GSO) possesses anti-oxidative and anti-inflammatory properties towards human primary monocytes. The UF isolated from GSO was phytochemically characterized by GC-MS and HPLC. Freshly obtained human monocytes were used to analyse the effects of GSOUF (10-100 μg mL-1) on oxidative and inflammatory responses using FACS analysis, RT-qPCR, and ELISA procedures. GSOUF skewed the monocyte plasticity towards the anti-inflammatory non-classical CD14+CD16++ monocytes and reduced the inflammatory competence of LPS-treated human primary monocytes diminishing TNF-α, IL-1β, and IL-6 gene expression and secretion. In addition, GSOUF showed a strong reactive oxygen species (ROS)-scavenging activity, reducing significantly nitrite levels with a significant decrease in Nos2 gene expression. Our results suggest that the UF isolated from GSO has significant potential for the management of inflammatory and oxidative conditions and offer novel benefits derived from the consumption of GSO in the prevention of inflammation-related diseases.

  17. Impact of green tea extract addition on oxidative changes in the lipid fraction of pastry products.

    Science.gov (United States)

    Żbikowska, Anna; Kowalska, Małgorzata; Rutkowska, Jarosława; Kozłowska, Mariola; Onacik-Gür, Sylwia

    2017-01-01

    Alongside flour, fat is the key ingredient of sponge cakes, including those with long shelf lives. It is an unstable food component, whose quality and nutritional safety depend on the composition and pres- ence of oxidation products. Consumption of fat oxidation products adversely affects the human body and contributes to the incidence of a number of medical conditions. Qualitative changes in fats extracted from thermostat sponge cakes with and without antioxidant additions were determined in this study. In the study, two types of antioxidant were used: natural - green tea extract in three doses (0.02%; 0.2% and 1.0%) and synthetic BHA (0.02%) and 100%, solid bakery shortening. Sponge-cakes were thermostatted at temperatures 63°C after twenty-eight days. In this study, the quality of the lipid fraction was analyzed. The amount of primary (PV) and secondary (AnV) oxidation products was determined, and   a Rancimat test was performed. Adding antioxidants to fats varied in the degree to which oxidation processes of lipids fractions were inhibited. The peroxide value after twenty-eight days of thermostatting ranged from 3.57 meq O/kg (BHA) and 11.14 O meq/kg (extract content - 1%) to 62.85 meq O/kg (control sample). In turn, the value of AnV after the storage period ranged from 4.84 (BHA) and 6.71 (extract content - 1%) to 16.83 (control sample). The best protective effects in the process of oxidation was achieved by BHA. The longest in- duction time and the lowest peroxide value and anisidine value were obtained for this antioxidant. It was achieved after twenty-eight days of fat thermostatting. Nonetheless, the results demonstrated it is possible to use the commercially available green tea extract to slow the adverse process of fat oxidation in sponge cake products.

  18. Kinetics of abiotic nitrous oxide production via oxidation of hydroxylamine by particulate metals in seawater

    Science.gov (United States)

    Cavazos, A. R.; Taillefert, M.; Glass, J. B.

    2016-12-01

    The oceans are a significant of nitrous oxide (N2O) to the atmosphere. Current models of global oceanic N2­O flux focus on microbial N2O cycling and often ignore abiotic reactions, such as the thermodynamically favorable oxidation of the nitrification intermediate hydroxylamine (NH2OH) by Mn(IV) or Fe(III). At circumneutral pH, NH2OH oxidation is more thermodynamically favorable via Mn(IV) than Fe(III) reduction. We characterized the kinetics of NH2OH oxidation in synthetic ocean water at pH 5.1-8.8 using microsensor electrodes to measure real-time N2O production. N2O production rates and yield were greater when NH2OH was oxidized by Mn(IV) than Fe(III). Accordingly, the reduction of Mn(IV) was first order with respect to NH2OH whereas the reduction of Fe(III) was zero order with respect to NH2OH. Interestingly, the order of the reaction with respect to Mn(IV) appears to be negative whereas the reaction is second order with respect to Fe(III). The inverse order with respect to Mn(IV) may be due to the aggregation of particles in seawater, which decreases their surface area and changes their reactivity. Finally, the reaction is first order with respect to protons with Fe(III) as the oxidant but zero order with Mn(IV). The stronger effect of the pH on the reaction with Fe(III) as the oxidant compared to Mn(IV) reflects the stoichiometry of these two reactions, as each mole of N2O produced by Fe(III) reduction consumes eight protons while each mole of N2O produced with Mn(IV) as the oxidant requires only four protons. Our data show that abiotic NH2OH oxidation by Mn(IV) or Fe(III) particles may represent a significant source of N2O in seawater. These findings suggest that abiotic N2O production in marine waters may be significant in areas of the oceans where particulate metals originating from aerosols, dust, or rivers may react with NH2OH released from ammonia-oxidizing microorganisms.

  19. Kinetics of corrosion products release from nickel-base alloys corroding in primary water conditions. A new modeling of release

    International Nuclear Information System (INIS)

    Carrette, F.; Guinard, L.; Pieraggi, B.

    2002-01-01

    The radioactivity in the primary circuit arises mainly from the activation of corrosion products in the core of pressurised water reactors; corrosion products dissolve from the oxide scales developed on steam generator tubes of alloy 690. The controlling and modelling of this process require a detailed knowledge of the microstructure and chemical composition of oxide scales as well as the kinetics of their corrosion and dissolution. Alloy 690 was studied as tubes and sheets, with three various surface states (as-received, cold-worked, electropolished). Corrosion tests were performed at 325 C and 155 bar in primary water conditions (B/Li - 1000/2 ppm, [H 2 ] 30 cm 3 .kg -1 TPN, [O 2 ] < 5 ppb); test durations ranged between 24 and 2160 hours. Corrosion tests in the TITANE loop provided mainly corrosion and oxidation kinetics, and tests in the BOREAL loop yielded release kinetics. This study revealed asymptotic type kinetics. Characterisation of the oxide scales grown in representative conditions of the primary circuit was performed by several techniques (SEM, TEM, SIMS, XPS, GIXRD). These analyses revealed the essential role of the fine grained cold-worked scale present on as-received and cold-worked materials. This scale controls the corrosion and release phenomena. The kinetic study and the characterisation of the oxide scales contributed to the modelling of the corrosion/release process. A growth/dissolution model was proposed for corrosion product scales grown in non-saturated dynamic fluid. This model provided the temporal evolution of oxide scales and release kinetics for different species (Fe, Ni, Cr). The model was validated for several surface states and several alloys. (authors)

  20. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    Science.gov (United States)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  1. Chemical oxidation of unsymmetrical dimethylhydrazine transformation products in water

    Directory of Open Access Journals (Sweden)

    Madi Abilev

    2015-03-01

    Full Text Available Oxidation of unsymmetrical dimethylhydrazine (UDMH during a water treatment has several disadvantages including formation of stable toxic byproducts. Effectiveness of treatment methods in relation to UDMH transformation products is currently poorly studied. This work considers the effectiveness of chemical oxidants in respect to main metabolites of UDMH – 1-formyl-2,2-dimethylhydrazine, dimethylaminoacetontrile, N-nitrosodimethylamine and 1-methyl-1H-1,2,4-triazole. Experiments on chemical oxidation by Fenton's reagent, potassium permanganate and sodium nitrite were conducted. Quantitative determination was performed by HPLC. Oxidation products were identified by gas chromatography-mass spectrometry in combination with solid-phase microextraction. 1-Formyl-2,2-dimethylhydrazine was completely oxidized by Fenton's reagent with formation of formaldehyde N-formyl-N-methyl-hydrazone, 1,4-dihydro-1,4-dimethyl-5H-tetrazol-5-one by the action of potassium permanganate and N-methyl-N-nitro-methanamine in the presence of sodium nitrite. Oxidation of 1-formyl-2,2-dimethylhydrazine also resulted in formation of N-nitrosodimethylamine. Oxidation of dimethylaminoacetontrile proceeded with formation of hydroxyacetonitrile, dimethylformamide and 1,2,5-trimethylpyrrole. After 30 days, dimethylaminoacetontrile was not detected in the presence of Fenton’s reagent and potassium permanganate, but it’s concentration in samples with sodium nitrite was 77.3 mg/L. In the presence of Fenton’s reagent, potassium permanganate and sodium nitrite after 30 days, N-nitrosodimethylamine concentration decreased by 85, 80 and 50%, respectively. In control sample, N-nitrosodimethylamine concentration decreased by 50%, indicating that sodium nitrite has no effect of on N-nitrosodimethylamine concentration. Only Fenton's reagent allowed to reduce the concentration of 1-methyl-1H-1,2,4-triazole to 50% in 30 days. In the presence of other oxidants, 1-methyl-1H-1,2,4-triazole

  2. Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

    Science.gov (United States)

    Curreri, Peter A.

    2009-01-01

    This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and

  3. Fission product chemistry and aerosol behaviour in the primary circuit of a pressurised water reactor under severe accident conditions

    International Nuclear Information System (INIS)

    Bowsher, B.R.

    1985-09-01

    Three key accident sequences are considered covering a representative range of different environments of pressure, flow, temperature history and degree of zircaloy oxidation, and their principle thermal hydraulic and physical characteristics affecting chemistry behaviour are identified. Inventories, chemical forms and timing of fission product release are summarized together with the major sources of structural materials and their release characteristics. Chemistry of each main fission product species is reviewed from available experimental and/or theoretical data. Studies modelling primary circuit fission product behaviour are reviewed. Requirements for further study are assessed. (UK)

  4. Estimating Net Primary Productivity Using Satellite and Ancillary Data

    Science.gov (United States)

    Choudhury, Bhaskar J.

    2002-01-01

    The net primary productivity (C) or the annual rate of carbon accumulation per unit ground area by terrestrial plant communities is the difference of gross photosynthesis (A(sub g)) and respiration (R) per unit ground area. Available field observations show that R is a large and variable fraction of A(sub g), although it is generally recognized that there are considerable difficulties in determining these fluxes, and thus pose challenge in assessing the accuracy. Further uncertainties arise in extrapolating field measurements (which are acquired over a hectare or so area) to regional scale. Here, an approach is presented for determining these fluxes using satellite and ancillary data to be representative of regional scale and allow assessment of interannual variation. A, has been expressed as the product of radiation use efficiency for gross photosynthesis by an unstressed canopy and intercepted photosynthetically active radiation, which is then adjusted for stresses due to soil water shortage and temperature away from optimum. R has been calculated as the sum of growth and maintenance components (respectively, R(sub g) and R(sub m)).The R(sub m) has been determined from nitrogen content of plant tissue per unit ground area, while R(sub g) has been obtained as a fraction of the difference of A(sub g) and R(sub m). Results for five consecutive years (1986-1990) are presented for the Amazon-Tocontins, Mississippi, and Ob River basins.

  5. Two-Step Electrochemical Intercalation and Oxidation of Graphite for the Mass Production of Graphene Oxide.

    Science.gov (United States)

    Cao, Jianyun; He, Pei; Mohammed, Mahdi A; Zhao, Xin; Young, Robert J; Derby, Brian; Kinloch, Ian A; Dryfe, Robert A W

    2017-12-06

    Conventional chemical oxidation routes for the production of graphene oxide (GO), such as the Hummers' method, suffer from environmental and safety issues due to their use of hazardous and explosive chemicals. These issues are addressed by electrochemical oxidation methods, but such approaches typically have a low yield due to inhomogeneous oxidation. Herein we report a two-step electrochemical intercalation and oxidation approach to produce GO on the large laboratory scale (tens of grams) comprising (1) forming a stage 1 graphite intercalation compound (GIC) in concentrated sulfuric acid and (2) oxidizing and exfoliating the stage 1 GIC in an aqueous solution of 0.1 M ammonium sulfate. This two-step approach leads to GO with a high yield (>70 wt %), good quality (>90%, monolayer), and reasonable oxygen content (17.7 at. %). Moreover, the as-produced GO can be subsequently deeply reduced (3.2 at. % oxygen; C/O ratio 30.2) to yield highly conductive (54 600 S m -1 ) reduced GO. Electrochemical capacitors based on the reduced GO showed an ultrahigh rate capability of up to 10 V s -1 due to this high conductivity.

  6. Oxidative stress induced inflammation initiates functional decline of tear production.

    Directory of Open Access Journals (Sweden)

    Yuichi Uchino

    Full Text Available Oxidative damage and inflammation are proposed to be involved in an age-related functional decline of exocrine glands. However, the molecular mechanism of how oxidative stress affects the secretory function of exocrine glands is unclear. We developed a novel mev-1 conditional transgenic mouse model (Tet-mev-1 using a modified tetracycline system (Tet-On/Off system. This mouse model demonstrated decreased tear production with morphological changes including leukocytic infiltration and fibrosis. We found that the mev-1 gene encodes Cyt-1, which is the cytochrome b(560 large subunit of succinate-ubiquinone oxidoreductase in complex II of mitochondria (homologous to succinate dehydrogenase C subunit (SDHC in humans. The mev-1 gene induced excessive oxidative stress associated with ocular surface epithelial damage and a decrease in protein and aqueous secretory function. This new model provides evidence that mitochondrial oxidative damage in the lacrimal gland induces lacrimal dysfunction resulting in dry eye disease. Tear volume in Tet-mev-1 mice was lower than in wild type mice and histopathological analyses showed the hallmarks of lacrimal gland inflammation by intense mononuclear leukocytic infiltration and fibrosis in the lacrimal gland of Tet-mev-1 mice. These findings strongly suggest that oxidative stress can be a causative factor for the development of dry eye disease.

  7. Cu/Nitroxyl Catalyzed Aerobic Oxidation of Primary Amines into Nitriles at Room Temperature.

    Science.gov (United States)

    Kim, Jinho; Stahl, Shannon S

    2013-07-05

    An efficient catalytic method has been developed for aerobic oxidation of primary amines to the corresponding nitriles. The reactions proceed at room temperature and employ a catalyst consisting of (4,4'- t Bu 2 bpy)CuI/ABNO (ABNO = 9-azabicyclo[3.3.1]nonan-3-one N -oxyl). The reactions exhibit excellent functional group compatibility and substrate scope, and are effective with benzylic, allylic and aliphatic amines. Preliminary mechanistic studies suggest that aerobic oxidation of the Cu catalyst is the turnover-limiting step of the reaction.

  8. Cu/Nitroxyl Catalyzed Aerobic Oxidation of Primary Amines into Nitriles at Room Temperature

    OpenAIRE

    Kim, Jinho; Stahl, Shannon S.

    2013-01-01

    An efficient catalytic method has been developed for aerobic oxidation of primary amines to the corresponding nitriles. The reactions proceed at room temperature and employ a catalyst consisting of (4,4′-tBu2bpy)CuI/ABNO (ABNO = 9-azabicyclo[3.3.1]nonan-3-one N-oxyl). The reactions exhibit excellent functional group compatibility and substrate scope, and are effective with benzylic, allylic and aliphatic amines. Preliminary mechanistic studies suggest that aerobic oxidation of the Cu catalyst...

  9. Kinetics and mechanism of the selective oxidation of primary aliphatic alcohols under phase transfer catalysis

    Directory of Open Access Journals (Sweden)

    K. Bijudas

    2014-03-01

    Full Text Available Kinetics of the oxidation of primary aliphatic alcohols has been carried out using phase transferred monochromate in benzene. Tetrabutylammonium bromide (TBAB and tetrabutylphosphonium bromide (TBPB are used as phase transfer catalysts (PT catalyst. The reaction shows first order dependence on both [alcohol] and [monochromate ion]. The oxidation leads to the formation of corresponding aldehyde and no traces of carboxylic acid has been detected. The reaction mixture failed to induce the polymerization of added acrylonitrile which rules out the presence radical intermediates in the reaction. Various thermodynamic parameters have been evaluated and a suitable mechanism has been proposed.

  10. Thermodynamics and the transport of corrosion products in PWR primary circuits

    International Nuclear Information System (INIS)

    Turner, D.J.

    1992-01-01

    It is argued that practically useful models for the activation, transport and deposition of corrosion products in PWR primary circuits can only be produced on the basis of an improved understanding of the chemical processes which control them. In particular, if a model is to make reliable predictions it is essential that its thermodynamic basis be sound. This is not the case with most current models which employ the erroneous concept of a corrosion product 'solubility'. In addition to the misuse of this term, other complications are discussed. These include the need to take account of the consequences of Gibbs' phase rule and the fact that, for mixed spinels, neither the concept of a thermodynamic solubility nor of a solubility product is valid. There is no reason to believe that measured apparent solubilities of nickel ferrites or spinel mixtures containing cobalt can give any direct guidance on the direction of transport of Ni or Co in PWR primary circuits. This is more likely to be determined by the distribution of stable and unstable ferrites and chromites than by any temperature coefficient of apparent solubility. Most of the transport of Ni and Co into and out of the core probably occurs as a consequence of either chemical or mechanical transients. Most important is likely to be the oxidative destruction and subsequent re-precipitation of chromites which occurs as a consequence of the oxygenated conditions employed during plant shutdown. (author)

  11. Palaeoceanographic controls on geochemical characteristics of organic-rich Exshaw mudrocks: role of enhanced primary production

    Energy Technology Data Exchange (ETDEWEB)

    Caplan, M.L.; Bustin, R.M. [University of British Columbia, Vancouver (Canada). Dept. of Earth and Ocean Sciences

    1999-07-01

    Organic-rich source rocks have generally been attributed to enhanced preservation of organic matter under anoxic bottom waters. Here geochemical analysis of kerogen and whole rock samples of organic-rich (lithofacies B{sub 1}) and organic-lean (lithofacies B{sub 2}) laminated mudrocks of the Devonian-Carboniferous Exshaw Formation, Alberta, highlight the importance of primary production in governing the quantity and quality of organic matter. Lower Si/Al, K/Al, Ti/Al and quartz/clay ratios in lithofacies B{sub 2}, similar maceral types and the laminated fabric of the two lithofacies indicate that the quality and quantity of organic matter are not related to grain size, redox or organic matter source changes. High Total Organic Carbon (TOC) and Hydrogen Index (HI), low Oxidation Index (Ox.I. ratio of oxygen functional groups to aliphatic groups derived by FTIR), lighter {delta}{sup 15}N{sub tot} and heavier {delta}{sup 13}C{sub org} isotopes indicate that kerogen of lithofacies B{sub 1} accumulated during periods of high organic-carbon production and delivery of relatively fresh, labile, well-preserved organic matter to the sea floor. In contrast, low TOC, HI, high Ox.I., heavier {delta}{sup 15}N{sub tot} and lighter {delta}{sup 13}C{sub org} isotopes indicate low primary productivity and delivery, high recycling and poor preservation of organic matter during accumulation of lithofacies B{sub 2}. (author)

  12. Impact of primary amine group from aminophospholipids and amino acids on marine phospholipids stability: Non-enzymatic browning and lipid oxidation

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    2013-01-01

    The main objective of this study was to investigate the oxidative stability and non-enzymatic browning reactions of marine PL in the presence or in the absence of primary amine group from aminophospholipids and amino acids. Marine phospholipids liposomal dispersions were prepared from two authentic......) Strecker derived volatiles, (ii) yellowness index (YI), (iii) hydrophobic and (iv) hydrophilic pyrroles content. The oxidative stability of the samples was assessed through measurement of secondary lipid derived volatile oxidation products. The result showed that the presence of PE and amino acids caused...... the formation of pyrroles, generated Strecker derived volatiles, decreased the YI development and lowered lipid oxidation. The lower degree of lipid oxidation in liposomal dispersions containing amino acids might be attributed to antioxidative properties of pyrroles or amino acids....

  13. Dispersion strengthening of aluminium-aluminium-oxide products

    DEFF Research Database (Denmark)

    Hansen, Niels

    1970-01-01

    The true stress-true strain curves at room temperature and at 400°C were determined for various types of aluminium-aluminium-oxide products containing from 0.2 to 4.7 weight per cent of aluminium oxide. The effect of particles on the initial flow stress and the flow stress for 0.2% offset at room...... temperature and at 400°C is in agreement with Orowan's theory. The increase in flow stress at room temperature for strain values below 3 per cent was related to the plastic strain by the equation σ-σoy=k1ε 1/2, where σoy is the initial flow stress and where k1 increases for increasing volume fraction...... and decreasing particle size of the dispersed particles. A general expression for k1 was derived for the relationship between the dislocation density and the strain in dispersion-strengthened products...

  14. Identification of the Products of Oxidation of Quercetin by Air Oxygenat Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Viktor A Utsal

    2007-03-01

    Full Text Available Oxidation of quercetin by air oxygen takes place in water and aqueous ethanol solutions under mild conditions, namely in moderately-basic media (pH ∼ 8-10 at ambient temperature and in the absence of any radical initiators, without enzymatic catalysis or irradiation of the reaction media by light. The principal reaction products are typical of other oxidative degradation processes of quercetin, namely 3,4-dihydroxy-benzoic (proto-catechuic and 2,4,6-trihydroxybenzoic (phloroglucinic acids, as well as the decarboxylation product of the latter – 1,3,5-trihydroxybenzene (phloroglucinol. In accordance with the literature data, this process involves the cleavage of the γ-pyrone fragment (ring C of the quercetin molecule by oxygen, with primary formation of 4,6-dihydroxy-2-(3,4-dihydroxybenzoyloxybenzoic acid (depside. However under such mild conditions the accepted mechanism of this reaction (oxidative decarbonylation with formation of carbon monoxide, CO should be reconsidered as preferably an oxidative decarboxylation with formation of carbon dioxide, CO2. Direct head-space analysis of the gaseous components formed during quercetin oxidation in aqueous solution at ambient temperature indicates that the ratio of carbon dioxide/carbon monoxide in the gas phase after acidification of the reaction media is ca. 96:4 %. Oxidation under these mild conditions is typical for other flavonols having OH groups at C3 (e.g., kaempferol, but it is completely suppressed if this hydroxyl group is substituted by a glycoside fragment (as in rutin, or a methyl substituent. An alternative oxidation mechanism involving the direct cleavage of the C2-C3 bond in the diketo-tautomer of quercetin is proposed.

  15. Production and consumption of nitric oxide by three methanotrophic bacteria.

    Science.gov (United States)

    Ren, T; Roy, R; Knowles, R

    2000-09-01

    We studied nitrogen oxide production and consumption by methanotrophs Methylobacter luteus (group I), Methylosinus trichosporium OB3b (group II), and an isolate from a hardwood swamp soil, here identified by 16S ribosomal DNA sequencing as Methylobacter sp. strain T20 (group I). All could consume nitric oxide (nitrogen monoxide, NO), and produce small amounts of nitrous oxide (N(2)O). Only Methylobacter strain T20 produced large amounts of NO (>250 parts per million by volume [ppmv] in the headspace) at specific activities of up to 2.0 x 10(-17) mol of NO cell(-1) day(-1), mostly after a culture became O(2) limited. Production of NO by strain T20 occurred mostly in nitrate-containing medium under anaerobic or nearly anaerobic conditions, was inhibited by chlorate, tungstate, and O(2), and required CH(4). Denitrification (methanol-supported N(2)O production from nitrate in the presence of acetylene) could not be detected and thus did not appear to be involved in the production of NO. Furthermore, cd(1) and Cu nitrite reductases, NO reductase, and N(2)O reductase could not be detected by PCR amplification of the nirS, nirK, norB, and nosZ genes, respectively. M. luteus and M. trichosporium produced some NO in ammonium-containing medium under aerobic conditions, likely as a result of methanotrophic nitrification and chemical decomposition of nitrite. For Methylobacter strain T20, arginine did not stimulate NO production under aerobiosis, suggesting that NO synthase was not involved. We conclude that strain T20 causes assimilatory reduction of nitrate to nitrite, which then decomposes chemically to NO. The production of NO by methanotrophs such as Methylobacter strain T20 could be of ecological significance in habitats near aerobic-anaerobic interfaces where fluctuating O(2) and nitrate availability occur.

  16. Size characterization of metal oxide nanoparticles in commercial sunscreen products

    Science.gov (United States)

    Bairi, Venu Gopal; Lim, Jin-Hee; Fong, Andrew; Linder, Sean W.

    2017-07-01

    There is an increase in the usage of engineered metal oxide (TiO2 and ZnO) nanoparticles in commercial sunscreens due to their pleasing esthetics and greater sun protection efficiency. A number of studies have been done concerning the safety of nanoparticles in sunscreen products. In order to do the safety assessment, it is pertinent to develop novel analytical techniques to analyze these nanoparticles in commercial sunscreens. This study is focused on developing analytical techniques that can efficiently determine particle size of metal oxides present in the commercial sunscreens. To isolate the mineral UV filters from the organic matrices, specific procedures such as solvent extraction were identified. In addition, several solvents (hexane, chloroform, dichloromethane, and tetrahydrofuran) have been investigated. The solvent extraction using tetrahydrofuran worked well for all the samples investigated. The isolated nanoparticles were characterized by using several different techniques such as transmission electron microscopy, scanning electron microscopy, dynamic light scattering, differential centrifugal sedimentation, and x-ray diffraction. Elemental analysis mapping studies were performed to obtain individual chemical and morphological identities of the nanoparticles. Results from the electron microscopy techniques were compared against the bulk particle sizing techniques. All of the sunscreen products tested in this study were found to contain nanosized (≤100 nm) metal oxide particles with varied shapes and aspect ratios, and four among the 11 products were showed to have anatase TiO2.

  17. Mesoporous Niobium Oxide Spheres as an Effective Catalyst for the Transamidation of Primary Amides with Amines

    KAUST Repository

    Ghosh, Subhash Chandra; Li, Cheng Chao; Zeng, Hua Chun; Ngiam, Joyce S Y; Seayad, Abdul M.; Chen, Anqi

    2014-01-01

    Mesoporous niobium oxide spheres (MNOS), conveniently prepared by a novel antisolvent precipitation approach, have been shown to be an effective catalyst for the transamidation of primary amides with amines. This novel transamidation can be efficiently carried out under solvent-free conditions and is applicable to a wide range of primary amides and amines to provide N-alkyl amides in good to excellent yields. The catalyst is highly stable and reusable. The application of this transamidation reaction has been demonstrated in the synthesis of antidepressant drug moclobemide and other druglike compounds. © 2014 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.

  18. Mesoporous Niobium Oxide Spheres as an Effective Catalyst for the Transamidation of Primary Amides with Amines

    KAUST Repository

    Ghosh, Subhash Chandra

    2014-02-06

    Mesoporous niobium oxide spheres (MNOS), conveniently prepared by a novel antisolvent precipitation approach, have been shown to be an effective catalyst for the transamidation of primary amides with amines. This novel transamidation can be efficiently carried out under solvent-free conditions and is applicable to a wide range of primary amides and amines to provide N-alkyl amides in good to excellent yields. The catalyst is highly stable and reusable. The application of this transamidation reaction has been demonstrated in the synthesis of antidepressant drug moclobemide and other druglike compounds. © 2014 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.

  19. Environmentally friendly chemoselective oxidation of primary aliphatic amines by using a biomimetic electrocatalytic system.

    Science.gov (United States)

    Largeron, Martine; Chiaroni, Angèle; Fleury, Maurice-Bernard

    2008-01-01

    Environmentally friendly oxidation of primary aliphatic amines to imines has been successfully achieved, under metal-free conditions, by the use of diverse electrogenerated o-azaquinone mediators. High catalytic performance, together with high chemoselectivity, were observed with electron-poor o-azaquinone catalysts generated from 2-aminoresorcinol derivatives. Similar to copper amine oxidase enzymes, these mediators exhibited lower reactivity toward alpha-branched primary amines and no reactivity toward secondary amines. In the case of 3,4-aminophenol derivatives lacking a 2-hydroxy group, the generated o-azaquinone species failed to catalyze the oxidation of the amine to the corresponding imine. Further mechanistic considerations allowed a rationalization of the crucial role of the 2-hydroxy group in converting a catalytically inert species into a highly effective biomimetic catalyst.

  20. Shell biofilm-associated nitrous oxide production in marine molluscs

    DEFF Research Database (Denmark)

    Heisterkamp, I.M.; Schramm, Andreas; Larsen, Lone Heimann

    2013-01-01

    Emission of the greenhouse gas nitrous oxide (N2O) from freshwater and terrestrial invertebrates has exclusively been ascribed to N2O production by ingested denitrifying bacteria in the anoxic gut of the animals. Our study of marine molluscs now shows that also microbial biofilms on shell surfaces...... are important sites of N2O production. The shell biofilms of Mytilus edulis, Littorina littorea and Hinia reticulata contributed 18-94% to the total animal-associated N2O emission. Nitrification and denitrification were equally important sources of N2O in shell biofilms as revealed by 15N-stable isotope...... mollusc species. Ammonium excretion by the animals was found to be sufficient to sustain N2O production in the shell biofilm. Apparently, the animals provide a nutrient-enriched microenvironment that stimulates growth and N2O production of the shell biofilm. This animal-induced stimulation...

  1. Mo-V-Te-Nb oxides as catalysts for ethene production by oxidative dehydrogenation of ethane

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, D. [Technische Universitaet Muenchen, Garching (Germany). Dept. of Chemistry and Catalysis Research Center; Meiswinkel, A.; Thaller, C.; Bock, M.; Alvarado, L. [Linde AG, Pullach (Germany)

    2013-11-01

    The availability of ethane in shale gas, as well as the interest in valorising previously underutilized carbon feedstocks, makes the oxidative dehydrogenation (ODH) of ethane an attractive alternative to the industrially established processes for production of ethylene. Mo-V-Te-Nb mixed oxide has been chosen as catalyst for the ODH reaction in view of its outstanding ability to activate alkane molecules. Catalytic test results showed that this type of catalyst can selectively oxidize ethane to ethene at moderate temperatures (350-400 C) with minor production of CO{sub x}. The catalytic performance of Mo-V-Te-Nb mixed-oxide is mainly attributable to the crystalline phase 'M1'. Rietveld analysis of the X-Ray diffractograms allowed us to quantify the amount of MoVTeNb oxide that has crystallized as M1. In this way, it was possible to find a linear correlation of the reaction rate with the abundance of M1 in the solid. Therefore, it is clear that for improving the efficiency of MoVTeNb oxide in ODH, the amount of M1 in the catalyst should be maximized. With this purpose, several MoVTeNb oxides were subject to different thermal treatments prior to the catalytic test. Structural changes in the catalyst were monitored by in-situ XRD technique. Under oxidative atmosphere, it was observed a recrystallization of M2 and possibly, amorphous oxide, into M1 phase, leading to correspondingly more active and selective catalysts (selectivities above 95 % for ethane conversions up to 40 % under industrially relevant conditions). The active site of M1 involves V species, likely with redox properties enhanced by the proximity of Mo and Te species, while the function of the crystalline structure itself is to provide the spatial configuration that allows interaction between these species. However, ethene formation rate was observed to be independent of the V content of the samples. The vanadium species exposed at the surface were studied by LEIS and by IR spectroscopy of CO

  2. Free radicals and antioxidants in primary fibromyalgia: an oxidative stress disorder?

    Science.gov (United States)

    Bagis, Selda; Tamer, Lulufer; Sahin, Gunsah; Bilgin, Ramazan; Guler, Hayal; Ercan, Bahadir; Erdogan, Canan

    2005-04-01

    The role of free radicals in fibromyalgia is controversial. In this study, 85 female patients with primary fibromyalgia and 80 age-, height-, and weight-matched healthy women were evaluated for oxidant/antioxidant balance. Malondialdehyde is a toxic metabolite of lipid peroxidation used as a marker of free radical damage. Superoxide dismutase is an intracellular antioxidant enzyme and shows antioxidant capacity. Pain was assessed by visual analog scale. Tender points were assessed by palpation. Age, smoking, body mass index (BMI), and duration of disease were also recorded. Malondialdehyde levels were significantly higher and superoxide dismutase levels significantly lower in fibromyalgic patients than controls. Age, BMI, smoking, and duration of disease did not affect these parameters. We found no correlation between pain and number of tender points. In conclusion, oxidant/antioxidant balances were changed in fibromyalgia. Increased free radical levels may be responsible for the development of fibromyalgia. These findings may support the hypothesis of fibromyalgia as an oxidative disorder.

  3. Solvent free oxidation of primary alcohols and diols using thymine iron(III) catalyst.

    Science.gov (United States)

    Al-Hunaiti, Afnan; Niemi, Teemu; Sibaouih, Ahlam; Pihko, Petri; Leskelä, Markku; Repo, Timo

    2010-12-28

    In this study, we developed an efficient and selective iron-based catalyst system for the synthesis of ketones from secondary alcohols and carboxylic acids from primary alcohol. In situ generated iron catalyst of thymine-1-acetate (THA) and FeCl(3) under solvent-free condition exhibits high activity. As an example, 1-octanol and 2-octanol were oxidized to 1-octanoic acid and 2-octanone with 89% and 98% yields respectively.

  4. Arginase expression modulates nitric oxide production in Leishmania (Leishmania) amazonensis.

    Science.gov (United States)

    Acuña, Stephanie Maia; Aoki, Juliana Ide; Laranjeira-Silva, Maria Fernanda; Zampieri, Ricardo Andrade; Fernandes, Juliane Cristina Ribeiro; Muxel, Sandra Marcia; Floeter-Winter, Lucile Maria

    2017-01-01

    Arginase is an enzyme that converts L-arginine to urea and L-ornithine, an essential substrate for the polyamine pathway supporting Leishmania (Leishmania) amazonensis replication and its survival in the mammalian host. L-arginine is also the substrate of macrophage nitric oxide synthase 2 (NOS2) to produce nitric oxide (NO) that kills the parasite. This competition can define the fate of Leishmania infection. The transcriptomic profiling identified a family of oxidoreductases in L. (L.) amazonensis wild-type (La-WT) and L. (L.) amazonensis arginase knockout (La-arg-) promastigotes and axenic amastigotes. We highlighted the identification of an oxidoreductase that could act as nitric oxide synthase-like (NOS-like), due to the following evidences: conserved domain composition, the participation of NO production during the time course of promastigotes growth and during the axenic amastigotes differentiation, regulation dependence on arginase activity, as well as reduction of NO amount through the NOS activity inhibition. NO quantification was measured by DAF-FM labeling analysis in a flow cytometry. We described an arginase-dependent NOS-like activity in L. (L.) amazonensis and its role in the parasite growth. The increased detection of NO production in the mid-stationary and late-stationary growth phases of La-WT promastigotes could suggest that this production is an important factor to metacyclogenesis triggering. On the other hand, La-arg- showed an earlier increase in NO production compared to La-WT, suggesting that NO production can be arginase-dependent. Interestingly, La-WT and La-arg- axenic amastigotes produced higher levels of NO than those observed in promastigotes. As a conclusion, our work suggested that NOS-like is expressed in Leishmania in the stationary growth phase promastigotes and amastigotes, and could be correlated to metacyclogenesis and amastigotes growth in a dependent way to the internal pool of L-arginine and arginase activity.

  5. Effect of primary air content on formation of nitrogen oxides during combustion of Ehkibastuz coal

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Imankulov, Eh.R.

    1986-01-01

    Investigations are discussed carried out in a pilot plant at the Kaz. Power Engineering Scientific Research Institute into the effect of the amount of primary air in coal-dust flame on the final concentration of nitrogen oxides in flue gases. The tests were carried out in a 7500 mm high, 1600 mm dia vertical cylindrical combustion chamber having type P-57 burner, and air dispersed fuel plus additional air supplies located at the top. Amounts of coal dust fed by a drum feeder along the air pipe varied from 100-600 kg/h. The required air was supplied by 5000 m/sup 3//h Type TK-700/5 blowers at 0.04 MPa. Ehkibastuz coal samples contained: 1.3% moisture; 48.1% ash; 38.02% carbon; 2.56% hydrogen; 0.73% sulfur; 0.60% nitrogen; heat of combustion was 14.3 MJ/kg. Results obtained indicate that variations in the amount of primary air in swirl flow burners affect formation of fuel nitrogen; there is an optimum volume at which minimum quantities of nitrogen oxides are formed. Either an increase or decrease in the primary air results in a rise in nitrogen oxide concentration. 3 references.

  6. Photoelectrochemical and electrocatalytic properties of thermally oxidized copper oxide for efficient solar fuel production

    KAUST Repository

    Garcia Esparza, Angel T.; Limkrailassiri, Kevin; Leroy, Fré dé ric; Rasul, Shahid; Yu, Weili; Lin, Liwei; Takanabe, Kazuhiro

    2014-01-01

    We report the use of a facile and highly scalable synthesis process to control growth products of earth-abundant Cu-based oxides and their application in relevant photoelectrochemical and electrochemical solar fuel generation systems. Characterization of the synthesized Cu(I)/Cu(II) oxides indicates that their surface morphology and chemical composition can be simply tuned by varying two synthesis parameters (time and temperature). UV-Vis spectroscopy and impedance spectroscopy studies are performed to estimate the band structures and electronic properties of these p-type semiconductor materials. Photoelectrodes made of Cu oxides possess favorable energy band structures for production of hydrogen from water; the position of their conduction band is ≈1 V more negative than the water-reduction potential. High acceptor concentrations on the order of 1018-1019 cm-3 are obtained, producing large electric fields at the semiconductor-electrolyte interface and thereby enhancing charge separation. The highly crystalline pristine samples used as photocathodes in photoelectrochemical cells exhibit high photocurrents under AM 1.5G simulated illumination. When the samples are electrochemically reduced under galvanostatic conditions, the co-existence of the oxide with metallic Cu on the surface seems to function as an effective catalyst for the selective electrochemical reduction of CO2. © the Partner Organisations 2014.

  7. Large historical growth in global terrestrial gross primary production

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J. E.; Berry, J. A.; Seibt, U.; Smith, S. J.; Montzka, S. A.; Launois, T.; Belviso, S.; Bopp, L.; Laine, M.

    2017-04-05

    Growth in terrestrial gross primary production (GPP) may provide a feedback for climate change, but there is still strong disagreement on the extent to which biogeochemical processes may suppress this GPP growth at the ecosystem to continental scales. The consequent uncertainty in modeling of future carbon storage by the terrestrial biosphere constitutes one of the largest unknowns in global climate projections for the next century. Here we provide a global, measurement-based estimate of historical GPP growth using long-term atmospheric carbonyl sulfide (COS) records derived from ice core, firn, and ambient air samples. We interpret these records using a model that relates changes in the COS concentration to changes in its sources and sinks, the largest of which is proportional to GPP. The COS history was most consistent with simulations that assume a large historical GPP growth. Carbon-climate models that assume little to no GPP growth predicted trajectories of COS concentration over the anthropogenic era that differ from those observed. Continued COS monitoring may be useful for detecting ongoing changes in GPP while extending the ice core record to glacial cycles could provide further opportunities to evaluate earth system models.

  8. Spatial scaling of net primary productivity using subpixel landcover information

    Science.gov (United States)

    Chen, X. F.; Chen, Jing M.; Ju, Wei M.; Ren, L. L.

    2008-10-01

    Gridding the land surface into coarse homogeneous pixels may cause important biases on ecosystem model estimations of carbon budget components at local, regional and global scales. These biases result from overlooking subpixel variability of land surface characteristics. Vegetation heterogeneity is an important factor introducing biases in regional ecological modeling, especially when the modeling is made on large grids. This study suggests a simple algorithm that uses subpixel information on the spatial variability of land cover type to correct net primary productivity (NPP) estimates, made at coarse spatial resolutions where the land surface is considered as homogeneous within each pixel. The algorithm operates in such a way that NPP obtained from calculations made at coarse spatial resolutions are multiplied by simple functions that attempt to reproduce the effects of subpixel variability of land cover type on NPP. Its application to a carbon-hydrology coupled model(BEPS-TerrainLab model) estimates made at a 1-km resolution over a watershed (named Baohe River Basin) located in the southwestern part of Qinling Mountains, Shaanxi Province, China, improved estimates of average NPP as well as its spatial variability.

  9. Investigating smoke's influence on primary production throughout the Amazon

    Science.gov (United States)

    Flanner, M. G.; Mahowald, N. M.; Zender, C. S.; Randerson, J. T.; Tosca, M. G.

    2007-12-01

    Smoke from annual burning in the Amazon causes large reduction in surface insolation and increases the diffuse fraction of photosynthetically-active radiation (PAR). These effects have competing influence on gross primary production (GPP). Recent studies indicate that the sign of net influence depends on aerosol optical depth, but the magnitude of smoke's effect on continental-scale carbon cycling is very poorly constrained and may constitute an important term of fire's net impact on carbon storage. To investigate widespread effects of Amazon smoke on surface radiation properties, we apply a version of the NCAR Community Atmosphere Model with prognostic aerosol transport, driven with re-analysis winds. Carbon aerosol emissions are derived from the Global Fire Emissions Database (GFED). We use AERONET observations to identify model biases in aerosol optical depth, single-scatter albedo, and surface radiative forcing, and prescribe new aerosol optical properties based on field observations to improve model agreement with AERONET data. Finally, we quantify a potential range of smoke-induced change in large-scale GPP based on: 1) ground measurements of GPP in the Amazon as a function of aerosol optical depth and diffuse fraction of PAR, and 2) empirical functions of ecosystem-scale photosynthesis rates currently employed in models such as the Community Land Model (CLM).

  10. Design considerations of fission and corrosion product in primary system of MONJU

    International Nuclear Information System (INIS)

    Yanagisawa, T.; Akagane, K.; Yamamoto, K.; Kawashima, K.

    1976-01-01

    General influence of fission and corrosion products in primary system on MONJU plant design is reviewed. Various research and development works are now in progress to decrease the generation rate, to remove the products more effectively and to develop the methods of evaluation the behaviour of radioactive products. The inventory and distribution of fission and corrosion products in the primary circuit of MONJU are given. The radiation levels on the primary components are estimated to be several roentgens per hour. (author)

  11. Reducing the uncertainty of the primary damage production in Fe

    International Nuclear Information System (INIS)

    Bjorkas, C.; Nordlund, K.

    2007-01-01

    Full text of publication follows: One of the key questions for understanding neutron irradiation damage buildup in fission and fusion reactor steels is knowing the primary damage state produced by neutron-induced atomic recoils in Fe. Supporting this is our recent study revealing that the initial damage in Fe 0.9 Cr 0.1 is essentially the same as in pure Fe [1]. In spite of decades of study, the question of what the amount and distribution of defects in Fe is, has remained highly unclear. Different computer simulations modules have given a good qualitative understanding of the cascade development [1,2]. However, quantitative differences of more than a factor of three have remained in the predicted clustered defect production numbers [2]. The disagreements between the potentials pose problems for finding a reliable predictive model for the behavior of Fe under irradiation. In this study we analyze the initial damage as predicted by three recent interatomic potentials for Fe. These are well suited for a comparison because they have very different physical motivations and functional forms, but are comparable in overall quality and in particular reproduce the energetics of interstitials in different configurations well. The potentials are those by Ackland and Mendelev et al. (AMS) [3], the 'magnetic' potential by Dudarev and Derlet (DD) [4] and the Tersoff-like analytical potential by Mueller, Erhart and Albe (MEA) [5]. The DD and MEA potentials were modified by us to describe high-energy repulsive interactions well. All potentials were then used in recoil collision cascade simulations carried out and analyzed in exactly the same manner for all potentials. Analysis of the resulting damage showed a much smaller uncertainty regarding the damage production than that of previous potentials. The total defect production numbers essentially agree within the statistical uncertainty for the three potentials. Some differences remains regarding the defect clustered fractions, but

  12. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    Science.gov (United States)

    Totemeier, Terry C.; Pahl, Robert G.; Frank, Steven M.

    The oxidation behavior of hydride-bearing uranium metal corrosion products from Zero Power Physics Reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2, Ar-9%O 2, and Ar-20%O 2. Ignition of corrosion product samples from two moderately corroded plates was observed between 125°C and 150°C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride.

  13. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    International Nuclear Information System (INIS)

    Totemeier, T.C.; Pahl, R.G.; Frank, S.M.

    1998-01-01

    The oxidation behavior of hydride-bearing uranium metal corrosion products from zero power physics reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2 , Ar-9%O 2 , and Ar-20%O 2 . Ignition of corrosion product samples from two moderately corroded plates was observed between 125 C and 150 C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride. (orig.)

  14. Production of aromas and fragrances through microbial oxidation of monoterpenes

    Directory of Open Access Journals (Sweden)

    H. F. Rozenbaum

    2006-09-01

    Full Text Available Aromas and fragrances can be obtained through the microbial oxidation of monoterpenes. Many microorganisms can be used to carry out extremely specific conversions using substrates of low commercial value. However, for many species, these substrates are highly toxic, consequently inhibiting their metabolism. In this work, the conversion ability of Aspergillus niger IOC-3913 for terpenic compounds was examined. This species was preselected because of its high resistance to toxic monoterpenic substrates. Though it has been grown in media containing R-limonene (one of the cheapest monoterpenic hydrocarbons, which is widely available on the market, the species has not shown the ability to metabolize it, since biotransformation products were not detected in high resolution gas chromatography analyses. For this reason, other monoterpenes (alpha-pinene, beta-pinene and camphor were used as substrates. These compounds were shown to be metabolized by the selected strain, producing oxidized compounds. Four reaction systems were used: a biotransformation in a liquid medium with cells in growth b with pre-grown cultures c with cells immobilized in a synthetic polymer network and d in a solid medium to which the substrate was added via the gas phase. The main biotransformation products were found in all the reaction systems, although the adoption of previously cultivated cells seemed to favor biotransformation. Cell immobilization seemed to be a feasible strategy for alleviating the toxic effect of the substrate. Through mass spectrometry it was possible to identify verbenone and alpha-terpineol as the biotransformation products of alpha-pinene and beta-pinene, respectively. The structures of the other oxidation products are described.

  15. The production of iron oxide during peridotite serpentinization: Influence of pyroxene

    Directory of Open Access Journals (Sweden)

    Ruifang Huang

    2017-11-01

    Full Text Available Serpentinization produces molecular hydrogen (H2 that can support communities of microorganisms in hydrothermal fields; H2 results from the oxidation of ferrous iron in olivine and pyroxene into ferric iron, and consequently iron oxide (magnetite or hematite forms. However, the mechanisms that control H2 and iron oxide formation are poorly constrained. In this study, we performed serpentinization experiments at 311 °C and 3.0 kbar on olivine (with <5% pyroxene, orthopyroxene, and peridotite. The results show that serpentine and iron oxide formed when olivine and orthopyroxene individually reacted with a saline starting solution. Olivine-derived serpentine had a significantly lower FeO content (6.57 ± 1.30 wt.% than primary olivine (9.86 wt.%, whereas orthopyroxene-derived serpentine had a comparable FeO content (6.26 ± 0.58 wt.% to that of primary orthopyroxene (6.24 wt.%. In experiments on peridotite, olivine was replaced by serpentine and iron oxide. However, pyroxene transformed solely to serpentine. After 20 days, olivine-derived serpentine had a FeO content of 8.18 ± 1.56 wt.%, which was significantly higher than that of serpentine produced in olivine-only experiments. By contrast, serpentine after orthopyroxene had a slightly higher FeO content (6.53 ± 1.01 wt.% than primary orthopyroxene. Clinopyroxene-derived serpentine contained a significantly higher FeO content than its parent mineral. After 120 days, the FeO content of olivine-derived serpentine decreased significantly (5.71 ± 0.35 wt.%, whereas the FeO content of orthopyroxene-derived serpentine increased (6.85 ± 0.63 wt.% over the same period. This suggests that iron oxide preferentially formed after olivine serpentinization. Pyroxene in peridotite gained some Fe from olivine during the serpentinization process, which may have led to a decrease in iron oxide production. The correlation between FeO content and SiO2 or Al2O3 content in olivine- and

  16. Possibility of Localized Corrosion of PWR primary side materials in oxidative decontamination condition

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Yoon; Jung, Jun Young; Won, Huijun; Kim, Seon Byeong; Choi, Wangkyu; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Primary circuit of a PWR (radionuclides uptake in the inner oxide layer and oxide/metal interface occurred inevitably. Therefore, it is necessary to remove the inner oxide layer as well as the outer oxide layer to achieve excellent decontamination effects. It is known that the outer oxide layers are typically composed of Fe{sub 3}O{sub 4} and NiFe{sub 2}O{sub 4}. On the other hand, the inner oxide layers are composed of Cr{sub 2}O{sub 3}, (Ni{sub 1-x}Ni{sub x})(Cr{sub 1-y}Fe{sub y}){sub 2}O{sub 4}, and FeCr{sub 2}O{sub 4}. Because of chromium in the trivalent oxidation state which is difficult to dissolve, the oxide layer has an excellent protectiveness and is hard to decontaminate. For the dissolution of chromium-rich oxide, there have been developed an alkaline permanganate (AP) or nitric permanganate (NP). A disadvantage of the AP process is the generation of a large volume of secondary waste. On the other hand, NP process is highly incompatible to the corrosion of the structure materials. In this study as a part of developing decontamination process, we investigated the corrosion behavior of the structure materials such as Inconel-600 and type 304 stainless steel in NP and AP oxidative decontamination conditions for the safe use of an oxidative phase in PWR system decontamination. The corrosion behavior was analyzed through the potential-pH equilibrium for the system of Cr-H{sub 2}O / Mn-H{sub 2}O at 90 .deg. C and potentiodynamic polarization in a typical AP and NP solution were evaluated. The AP or NP treated specimen surface was observed using an optical microscope and scanning electron microscopy (SEM) for an evaluation of the localized corrosion. The possibility of localized corrosion of PWR primary side materials under oxidative decontamination condition was evaluated using a potentiodynamic polarization technique, observation of localized corrosion morphology, and consideration of potential-pH diagrams at 90 .deg. C. From the results of these tests, we

  17. Estimating Next Primary Productivity using Satellite and Ancillary Data

    Science.gov (United States)

    Choudhury, B. J.

    The net primary productivity (C) or annual rate of carbon accumulation per unit ground area by terrestrial plant communities is the difference of the rate of gross photosynthesis (Ag) and autotrophic respiration (R) per unit ground area. Although available observations show that R is a large and variable fraction of Ag, viz., 0.3 to 0.7, it is generally recognized that much uncertainties exist in this fraction due to difficulties associated with the needed measurements. Additional uncertainties arise when these measurements are extrapolated to regional or global land surface using empirical equations, for example, using regression equations relating C to mean annual precipitation and air temperature. Here, a process- based approach has been taken to calculate Ag and R using satellite and ancillary data. Ag has been expressed as a product of radiation use efficiency, magnitude of intercepted photosynthetically active radiation (PAR), and normalized by stresses due to soil water shortage and air temperature away from the optimum range. A biophysical model has been used to determine the radiation use efficiency from the maximum rate of carbon assimilation by a leaf, foliage temperature, and the fraction of diffuse PAR incident on a canopy. All meteorological data (PAR, air temperature, precipitation, etc.) needed for the calculation are derived from satellite observations, while a land use, land cover data (based on satellite and ground measurements) have been used to assess the maximum rate of carbon assimilation by a leaf of varied cover type based on field measurements. R has been calculated as the sum of maintenance and growth components. The maintenance respiration of foliage and live fine roots at a standard temperature of different land cover has been determined from their nitrogen content using field and satellite measurements, while that of living fraction of woody stem (viz., sapwood) from the seasonal maximum leaf area index as determined from satellite

  18. Benthic Light Availability Improves Predictions of Riverine Primary Production

    Science.gov (United States)

    Kirk, L.; Cohen, M. J.

    2017-12-01

    Light is a fundamental control on photosynthesis, and often the only control strongly correlated with gross primary production (GPP) in streams and rivers; yet it has received far less attention than nutrients. Because benthic light is difficult to measure in situ, surrogates such as open sky irradiance are often used. Several studies have now refined methods to quantify canopy and water column attenuation of open sky light in order to estimate the amount of light that actually reaches the benthos. Given the additional effort that measuring benthic light requires, we should ask if benthic light always improves our predictions of GPP compared to just open sky irradiance. We use long-term, high-resolution dissolved oxygen, turbidity, dissolved organic matter (fDOM), and irradiance data from streams and rivers in north-central Florida, US across gradients of size and color to build statistical models of benthic light that predict GPP. Preliminary results on a large, clear river show only modest model improvements over open sky irradiance, even in heavily canopied reaches with pulses of tannic water. However, in another spring-fed river with greater connectivity to adjacent wetlands - and hence larger, more frequent pulses of tannic water - the model improved dramatically with the inclusion of fDOM (model R2 improved from 0.28 to 0.68). River shade modeling efforts also suggest that knowing benthic light will greatly enhance our ability to predict GPP in narrower, forested streams flowing in particular directions. Our objective is to outline conditions where an assessment of benthic light conditions would be necessary for riverine metabolism studies or management strategies.

  19. Oxidative Stress in Shiga Toxin Production by Enterohemorrhagic Escherichia coli

    Directory of Open Access Journals (Sweden)

    Katarzyna Licznerska

    2016-01-01

    Full Text Available Virulence of enterohemorrhagic Escherichia coli (EHEC strains depends on production of Shiga toxins. These toxins are encoded in genomes of lambdoid bacteriophages (Shiga toxin-converting phages, present in EHEC cells as prophages. The genes coding for Shiga toxins are silent in lysogenic bacteria, and prophage induction is necessary for their efficient expression and toxin production. Under laboratory conditions, treatment with UV light or antibiotics interfering with DNA replication are commonly used to induce lambdoid prophages. Since such conditions are unlikely to occur in human intestine, various research groups searched for other factors or agents that might induce Shiga toxin-converting prophages. Among other conditions, it was reported that treatment with H2O2 caused induction of these prophages, though with efficiency significantly lower relative to UV-irradiation or mitomycin C treatment. A molecular mechanism of this phenomenon has been proposed. It appears that the oxidative stress represents natural conditions provoking induction of Shiga toxin-converting prophages as a consequence of H2O2 excretion by either neutrophils in infected humans or protist predators outside human body. Finally, the recently proposed biological role of Shiga toxin production is described in this paper, and the “bacterial altruism” and “Trojan Horse” hypotheses, which are connected to the oxidative stress, are discussed.

  20. Requirement of argininosuccinate lyase for systemic nitric oxide production.

    Science.gov (United States)

    Erez, Ayelet; Nagamani, Sandesh C S; Shchelochkov, Oleg A; Premkumar, Muralidhar H; Campeau, Philippe M; Chen, Yuqing; Garg, Harsha K; Li, Li; Mian, Asad; Bertin, Terry K; Black, Jennifer O; Zeng, Heng; Tang, Yaoping; Reddy, Anilkumar K; Summar, Marshall; O'Brien, William E; Harrison, David G; Mitch, William E; Marini, Juan C; Aschner, Judy L; Bryan, Nathan S; Lee, Brendan

    2011-11-13

    Nitric oxide (NO) is crucial in diverse physiological and pathological processes. We show that a hypomorphic mouse model of argininosuccinate lyase (encoded by Asl) deficiency has a distinct phenotype of multiorgan dysfunction and NO deficiency. Loss of Asl in both humans and mice leads to reduced NO synthesis, owing to both decreased endogenous arginine synthesis and an impaired ability to use extracellular arginine for NO production. Administration of nitrite, which can be converted into NO in vivo, rescued the manifestations of NO deficiency in hypomorphic Asl mice, and a nitric oxide synthase (NOS)-independent NO donor restored NO-dependent vascular reactivity in humans with ASL deficiency. Mechanistic studies showed that ASL has a structural function in addition to its catalytic activity, by which it contributes to the formation of a multiprotein complex required for NO production. Our data demonstrate a previously unappreciated role for ASL in NOS function and NO homeostasis. Hence, ASL may serve as a target for manipulating NO production in experimental models, as well as for the treatment of NO-related diseases.

  1. Molecular mechanism of catalase activity change under sodium dodecyl sulfate-induced oxidative stress in the mouse primary hepatocytes.

    Science.gov (United States)

    Wang, Jing; Wang, Jiaxi; Xu, Chi; Liu, Rutao; Chen, Yadong

    2016-04-15

    Sodium dodecyl sulfate (SDS) contributes to adverse effects of organisms probably because of its ability to induce oxidative stress via changing the activity of antioxidant enzyme catalase (CAT). But the underlying molecular mechanisms still remain unclear. This study characterized the harmful effects of SDS-induced oxidative stress on the mouse primary hepatocytes as well as the structure and function of CAT molecule and investigated the underlying molecular mechanism. After 12h SDS (0.1μM to 0.2mM) exposure, no significant change was observed in CAT activity of the hepatocytes. After 0.5 and 0.8mM SDS exposure, the state of oxidative stress stimulated CAT production in the hepatocytes. The inhibition of CAT activity induced by directly interacting with SDS was unable to catch the synthesis of CAT and therefore resulted in the increased activity and elevated ROS level. Further molecular experiments showed that SDS prefers to bind to the interface with no direct effect on the active site and the structure of heme groups of CAT molecule. When the sites in the interface is saturated, SDS interacts with VAL 73, HIS 74, ASN 147 and PHE 152, the key residues of the enzyme activity, and leads to the decrease of CAT activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Altered primary production during mass-extinction events

    NARCIS (Netherlands)

    van de Schootbrugge, B.; Gollner, S.

    2013-01-01

    The Big Five mass-extinction events are characterized by dramatic changes in primary producers. Initial disturbance to primary producers is usually followed by a succession of pioneers that represent qualitative and quantitative changes in standing crops of land plants and/or phytoplankton. On land,

  3. Production and analysis of ultradispersed uranium oxide powders

    Science.gov (United States)

    Zajogin, A. P.; Komyak, A. I.; Umreiko, D. S.; Umreiko, S. D.

    2010-05-01

    Spectroscopic studies are made of the laser plasma formed near the surface of a porous body containing nanoquantities of uranium compounds which is irradiated by two successive laser pulses. The feasibility of using laser chemical methods for obtaining nanoclusters of uranium oxide particles in the volume of a porous body and the simultaneous possibility of determining the uranium content with good sensitivity are demonstrated. The thermochemical and spectral characteristics of the analogs of their compounds with chlorine are determined and studied. The possibility of producing uranium dioxides under ordinary conditions and their analysis in the reaction products is demonstrated.

  4. Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Bucky Nanodiamond.

    Science.gov (United States)

    Lin, Yangming; Wu, Kuang-Hsu Tim; Yu, Linhui; Heumann, Saskia; Su, Dang Sheng

    2017-09-11

    Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemoselectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Bucky nanodiamond is a potential green catalyst that exhibits excellent chemoselectivity and cycling stability for the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocyclic, and linear chain alcohols) to their corresponding aldehydes. The results are comparable to reported transition-metal catalysts including conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of the oxidant and substrates by the surface oxygen groups and defect species are revealed with model catalysts, ex situ electrochemical measurements, and ex situ attenuated total reflectance. The zigzag edges of sp 2 carbon planes are shown to play a key role in these reactions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Lactate Dehydrogenase and Oxidative Stress Activity in Primary Open-Angle Glaucoma Aqueous Humour

    Directory of Open Access Journals (Sweden)

    Predrag Jovanović

    2010-02-01

    Full Text Available Lactate dehydrogenase (LDH and lactate are some of the hypoxy biochemical parameters. Extracellular activity of this enzyme increases under the condition of oxidative stress, since the cell integrity can be disrupted during the lipid peroxidation process. Subsequently that leads to the increase level of the lactic acid and lactic acid salts. The objective of this investigation is establishing the level of LDH, LDH1 (HBDH and the lactate concentration in aqueous humour in patients with primary open-angle glaucoma.Biochemical analysis have been made by enzymatic-colometric method (lactate and UV-kinetic method (LDH and HBDH in aqueous humour of 30 patients (42 eyes with primary open-angle glaucoma (POAG and 30 patients (40 eyes with cataract (the control group.The increased values of lactate and the activity of LDH and HBDH enzyme in aqueous humour of POAG patients in correlation with the control group are the results not only of oxidative stress but also of hypoxy and the mitochondry oxidative function (p<0,001.The increased activity of the examined biochemical parameters in the aqueous humour of the POAG patients points to the fact that other mechanisms, besides IOP, have a role in glaucoma pathogenesis.

  6. Microarc Oxidation of Product Surfaces without Using a Bath

    Directory of Open Access Journals (Sweden)

    V. K. Shatalov

    2015-01-01

    Full Text Available While using an electrochemical method to cover the large-sized work-pieces, units, and products up to 6 м3 by protective coating, there is a certain difficulty to apply traditional anodizing techniques in a plating vat, and it is necessary to find various processing techniques.To use the existing micro-arc oxide coating (MOC methods for work-pieces of various forms and sizes in a plating vat is complicated in case it is required to provide oxide layers in separate places rather than over entire surface of a work-piece. The challenge is to treat flat surfaces in various directions, external and internal surfaces of rotation bodies, profiled surfaces, intersections, closed and through holes, pipes, as well as spline and thread openings for ensuring anti-seize properties in individual or small-scale production to meet technical requirements and operational properties of products.A design of tools to provide MOC-process of all possible surfaces of various engineering box-type products depends on many factors and can be considerably different even when processing the surfaces of the same forms. An attachment to be used is fixed directly on a large-sized design (a work-piece, a product or fastened in the special tool. The features of technological process, design shape, and arrangement of the processed surfaces define a fastening method of the attachment. Therefore it is necessary to pay much attention to a choice of the processing pattern and a design of tools.The Kaluga-branch of Bauman Moscow State Technical University is an original proposer of methods to form MOC-coatings on the separate surfaces of large-sized work-pieces using the moved and stationary electrodes to solve the above listed tasks.The following results of work will have an impact on development of the offered processing methods and their early implementation in real production:1. To provide oxide coatings on the surfaces of large-sized products or assemblies in a single or small

  7. Aerobic nitrous oxide production through N-nitrosating hybrid formation in ammonia-oxidizing archaea.

    Science.gov (United States)

    Stieglmeier, Michaela; Mooshammer, Maria; Kitzler, Barbara; Wanek, Wolfgang; Zechmeister-Boltenstern, Sophie; Richter, Andreas; Schleper, Christa

    2014-05-01

    Soil emissions are largely responsible for the increase of the potent greenhouse gas nitrous oxide (N2O) in the atmosphere and are generally attributed to the activity of nitrifying and denitrifying bacteria. However, the contribution of the recently discovered ammonia-oxidizing archaea (AOA) to N2O production from soil is unclear as is the mechanism by which they produce it. Here we investigate the potential of Nitrososphaera viennensis, the first pure culture of AOA from soil, to produce N2O and compare its activity with that of a marine AOA and an ammonia-oxidizing bacterium (AOB) from soil. N. viennensis produced N2O at a maximum yield of 0.09% N2O per molecule of nitrite under oxic growth conditions. N2O production rates of 4.6±0.6 amol N2O cell(-1) h(-1) and nitrification rates of 2.6±0.5 fmol NO2(-) cell(-1) h(-1) were in the same range as those of the AOB Nitrosospira multiformis and the marine AOA Nitrosopumilus maritimus grown under comparable conditions. In contrast to AOB, however, N2O production of the two archaeal strains did not increase when the oxygen concentration was reduced, suggesting that they are not capable of denitrification. In (15)N-labeling experiments we provide evidence that both ammonium and nitrite contribute equally via hybrid N2O formation to the N2O produced by N. viennensis under all conditions tested. Our results suggest that archaea may contribute to N2O production in terrestrial ecosystems, however, they are not capable of nitrifier-denitrification and thus do not produce increasing amounts of the greenhouse gas when oxygen becomes limiting.

  8. Regulation of adrenomedullin and nitric oxide production by periodontal bacteria.

    Science.gov (United States)

    Hussain, Q A; McKay, I J; Gonzales-Marin, C; Allaker, R P

    2015-10-01

    In periodontitis the host response to bacterial challenge includes activity of the multifunctional molecules adrenomedullin (AM) and nitric oxide (NO). The aim of this study was to investigate the role of periodontal bacteria in regulating the production of these molecules from cultured cells. Regulation of AM and NO production from oral keratinocytes when challenged with culture supernatants from Aggregatibacter actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Veillonella atypica, Streptococcus salivarius and Candida albicans was examined. AM and NO were measured in cell culture supernatants using an enzyme-linked immunosorbent assay and the nitrate/nitrite (NO metabolites) Griess assay respectively. Cellular production of AM and inducible NO synthase was also analysed in target cells by immunofluorescence and Western blot analysis. The inter-relationship of AM and NO production were further investigated with macrophages. A. actinomycetemcomitans and C. rectus induced maximal levels of both AM and NO after 6 and 48 h respectively from oral keratinocytes. AM production in macrophages was upregulated in response to the NO donor S-nitrosoglutathione and partially blocked by the inducible NO synthase inhibitor, N(ω) -Nitro-l-arginine methyl ester hydrochloride. Likewise, NO production was increased upon exposure to AM, while the AM receptor antagonist AM 22-52 reduced the release of NO. Pathogens associated with aggressive periodontitis, A. actinomycetemcomitans and C. rectus, were more effective than those associated with chronic periodontitis, P. gingivalis and Prev. intermedia, and commensals, S. salivarius and V. atypica, as regards the upregulation of AM and NO production from oral keratinocytes. Interaction between these molecules was also demonstrated with macrophages. Understanding the coordinated regulation of AM and NO production in response to periodontal bacteria may identify

  9. Coupling Solid Oxide Electrolyser (SOE) and ammonia production plant

    International Nuclear Information System (INIS)

    Cinti, Giovanni; Frattini, Domenico; Jannelli, Elio; Desideri, Umberto; Bidini, Gianni

    2017-01-01

    Highlights: • An innovative NH 3 production plant was designed. • CO 2 emissions and energy consumption are studied in three different designs. • High temperature electrolysis allows to achieve high efficiency and heat recovery. • The coupling permits storage of electricity into a liquid carbon free chemical. - Abstract: Ammonia is one of the most produced chemicals worldwide and is currently synthesized using nitrogen separated from air and hydrogen from natural gas reforming with consequent high consumption of fossil fuel and high emission of CO 2 . A renewable path for ammonia production is desirable considering the potential development of ammonia as energy carrier. This study reports design and analysis of an innovative system for the production of green ammonia using electricity from renewable energy sources. This concept couples Solid Oxide Electrolysis (SOE), for the production of hydrogen, with an improved Haber Bosch Reactor (HBR), for ammonia synthesis. An air separator is also introduced to supply pure nitrogen. SOE operates with extremely high efficiency recovering high temperature heat from the Haber-Bosch reactor. Aspen was used to develop a model to study the performance of the plant. Both the SOE and the HBR operate at 650 °C. Ammonia production with zero emission of CO 2 can be obtained with a reduction of 40% of power input compared to equivalent plants.

  10. Tritium oxide uptake and desorption kinetics in a primary producer: chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Dunstall, T.G.

    1983-01-01

    The alga Chlorella pyrenoidosa grown in batch culture under chronic tritium oxide exposure was used to model behavior of tritium at the primary producer level of an aquatic food chain. The specific activity ratio of organically bound tritium to medium tritium increased during initial growth stages, then reached an asymptotic steady state value of 0.59 after approximately seven cell doublings. The intracellular to extracellular concentrations of tritium oxide appeared to be in equilibrium. Loss of previously formed organically bound tritium in cells transferred to tritium-free media averaged less than 5 % for exponential growth phase cultures which had undergone more than three cell doublings. Over a comparable time period, a greater loss of organically bound tritium from stationary cells (average 13.4 %) was attributed to increased degradative metabolism in senescent cultures. Concentration of tritium in organically bound form may exceed environmental tritium oxide levels under dynamic conditions in which a pulse of tritium oxide to the environment is dissipated over time

  11. Influence of dissolved hydrogen on oxide film and PWSCC of Alloy 600 in PWR primary water

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Tomokazu; Totsuka, Nobuo; Nakajima, Nobuo [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2001-09-01

    In order to investigate the influence of dissolved hydrogen (DH) on the corrosion behavior and PWSCC of Alloy 600 in primary water of PWR under actual operating temperature range, we carried out electrochemical polarization measurement, repassivation test, analysis of the oxide film on the alloy by AES, XPS and PWSCC test. In all cases, the content of DH was changed from 0 to 45 cc/kgH{sub 2}O. The anodic polarization curve reveals that the peak current density increases with increasing DH. The result of the repassivation test shows that the repassivation rate decreases with increasing DH, and the changes of the above two become larger between 11 and 22 cc/kgH{sub 2}O of DH. According to the results of oxide film analysis, it is seen that the oxide films formed below 11 cc/kgH{sub 2}O of DH are relatively thick and rich in Ni, but those formed at higher DH contents are relatively thin and rich in Cr and Fe. The susceptibility of the alloy to PWSCC has a peak at 11 cc/kgH{sub 2}O of DH, which reveals that the property of the oxide film may play important role in PWSCC of alloy. (author)

  12. Preparation of a primary target for the production of fission products in a nuclear reactor

    International Nuclear Information System (INIS)

    Arino, H.; Cosolito, F.J.; George, K.D.; Thornton, A.K.

    1976-01-01

    A primary target for the production of fission products in a nuclear reactor, such as uranium or plutonium fission products, is comprised of an enclosed, cylindrical vessel, preferably comprised of stainless steel, having a thin, continuous, uniform layer of fissionable material, integrally bonded to its inner walls and a port permitting access to the interior of the vessel. A process is also provided for depositing uranium material on to the inner walls of the vessel. Upon irradiation of the target with neutrons from a nuclear reactor, radioactive fission products, such as molybdenum-99, are formed, and thereafter separated from the target by the introduction of an acidic solution through the port to dissolve the irradiated inner layer. The irradiation and dissolution are thus effected in the same vessel without the necessity of transferring the fissionable material and fission products to a separate chemical reactor. Subsequently, the desired isotopes are extracted and purified. Molybdenum-99 decays to technetium-99m which is a valuable medical diagnostic radioisotope. 3 claims, 1 drawing figure

  13. Use of calcium oxide in palm oil methyl ester production

    Directory of Open Access Journals (Sweden)

    Kulchanat Prasertsit

    2014-04-01

    Full Text Available Introducing an untreated calcium oxide (CaO as a solid heterogeneous catalyst for biodiesel production from palm oil by transesterification was studied in this work. The four studied parameters were methanol to oil molar ratio, CaO catalyst concentration, reaction time, and water content. The results for palm oil show that when the water content is higher than 3%wt and the amount of CaO greater than 7%wt soap formation from saponification occurs. A higher methanol to oil molar ratio requires a higher amount of CaO catalyst to provide the higher product purity. The appropriate methanol to CaO catalyst ratio is about 1.56. Commercial grade CaO gives almost the same results as AR grade CaO. In addition, reusing commercial grade CaO for about 5 to 10 repetitions without catalyst regeneration drops the percentage of methyl ester purity approximately 5 to 10%, respectively.

  14. Electrochemical intercalation of lithium into polypyrrole/silver vanadium oxide composite used for lithium primary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong-Won; Popov, Branko N. [Center for Electrochemical Engineering, Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (United States)

    2006-10-20

    Hybrid composites of polypyrrole (PPy) and silver vanadium oxide (SVO) used for lithium primary batteries were chemically synthesized by an oxidative polymerization of pyrrole monomer on the SVO surface in an acidic medium. The composite electrode exhibited higher discharge capacity and better rate capability as compared with the pristine SVO electrode. The improvement in electrochemical performance of the composite electrode was due to PPy which accommodates lithium ions and also enhances the SVO utilization. Chronoamperometric and ac-impedance measurements indicated that lithium intercalation proceeds under the mixed control by interfacial charge transfer and diffusion. The enhanced SVO utilization in the composite electrode results from a facilitated kinetics of interfacial charge transfer in the presence of PPy. (author)

  15. Electrochemical intercalation of lithium into polypyrrole/silver vanadium oxide composite used for lithium primary batteries

    Science.gov (United States)

    Lee, Jong-Won; Popov, Branko N.

    Hybrid composites of polypyrrole (PPy) and silver vanadium oxide (SVO) used for lithium primary batteries were chemically synthesized by an oxidative polymerization of pyrrole monomer on the SVO surface in an acidic medium. The composite electrode exhibited higher discharge capacity and better rate capability as compared with the pristine SVO electrode. The improvement in electrochemical performance of the composite electrode was due to PPy which accommodates lithium ions and also enhances the SVO utilization. Chronoamperometric and ac-impedance measurements indicated that lithium intercalation proceeds under the mixed control by interfacial charge transfer and diffusion. The enhanced SVO utilization in the composite electrode results from a facilitated kinetics of interfacial charge transfer in the presence of PPy.

  16. Evaluating four mathematical models for nitrous oxide production by autotrophic ammonia-oxidizing bacteria.

    Science.gov (United States)

    Ni, Bing-Jie; Yuan, Zhiguo; Chandran, Kartik; Vanrolleghem, Peter A; Murthy, Sudhir

    2013-01-01

    There is increasing evidence showing that ammonia-oxidizing bacteria (AOB) are major contributors to N(2)O emissions from wastewater treatment plants (WWTPs). Although the fundamental metabolic pathways for N(2)O production by AOB are now coming to light, the mechanisms responsible for N(2)O production by AOB in WWTP are not fully understood. Mathematical modeling provides a means for testing hypotheses related to mechanisms and triggers for N(2)O emissions in WWTP, and can then also become a tool to support the development of mitigation strategies. This study examined the ability of four mathematical model structures to describe two distinct mechanisms of N(2)O production by AOB. The production mechanisms evaluated are (1) N(2)O as the final product of nitrifier denitrification with NO(2)- as the terminal electron acceptor and (2) N(2)O as a byproduct of incomplete oxidation of hydroxylamine (NH(2)OH) to NO(2)-. The four models were compared based on their ability to predict N(2)O dynamics observed in three mixed culture studies. Short-term batch experimental data were employed to examine model assumptions related to the effects of (1) NH4+ concentration variations, (2) dissolved oxygen (DO) variations, (3) NO(2)- accumulations and (4) NH(2OH as an externally provided substrate. The modeling results demonstrate that all these models can generally describe the NH4+, NO(2)-, and NO(3)- data. However, none of these models were able to reproduce all measured N(2)O data. The results suggest that both the denitrification and NH(2)OH pathways may be involved in N(2)O production and could be kinetically linked by a competition for intracellular reducing equivalents. A unified model capturing both mechanisms and their potential interactions needs to be developed with consideration of physiological complexity. Copyright © 2012 Wiley Periodicals, Inc.

  17. Products of BVOC oxidation: ozone and organic aerosols

    Science.gov (United States)

    Wildt, Jürgen; Andres, Stefanie; Carriero, Giulia; Ehn, Mikael; Fares, Silvano; Hoffmann, Thorsten; Hacker, Lina; Kiendler-Scharr, Astrid; Kleist, Einhard; Paoletti, Elena; Pullinen, Iida; Rohrer, Franz; Rudich, Yinon; Springer, Monika; Tillmann, Ralf; Wahner, Andreas; Wu, Cheng; Mentel, Thomas

    2015-04-01

    Biogenic Volatile Organic Compounds (BVOC) are important precursors in photochemical O3 and secondary organic aerosol (SOA) formation. We conducted a series of laboratory experiments with OH-induced oxidation of monoterpenes to elucidate pathways and efficiencies of O3 and SOA formation. At high NOx conditions ([BVOC] / [NOx] monoterpene mixes emitted from different plant species we observed increasing ozone formation with increasing [NOX]. Between 2 and 3 O3-molecules were formed from 1 monoterpene when ozone formation was BVOC limited. Under such high NOX conditions, new particle formation was suppressed. Increasing [BVOC] / [NOX] ratios caused increasing efficiency of new particle formation indicating that peroxy radicals are the key intermediates in both, photochemical ozone- and new particle formation. The classical chemistry of peroxy radicals is well established (e.g. Master Chemical Mechanism). Peroxy radicals are produced by addition of molecular oxygen to the alkyl radical formed after OH attack at the BVOC. They either react with NO which leads to ozone formation or they react with other peroxy radicals and form chemically stable products (hydroperoxides, alkoholes and ketones). Much less knowledge exists on such reactions for Highly Oxidized Peroxy Radicals, (HOPR). Such HOPR were observed during ozonolysis of several volatiles and, in case of monoterpenes as precursors, they can contain more than 12 Oxygen atoms (Mentel et al., 2015). Although the OH-initiated formation of HOPR is yet not fully understood, their basic gas phase reactions seem to follow classical photochemical rules. In reactions with NO they can act as precursor for O3 and in reactions with other HOPR or with classical less oxidized peroxy radicals they can form highly oxidized stable products and alkoxy radicals. In addition, HOPR-HOPR reactions lead to the formation of dimers that, in case of monoterpenes as reactants, consist of a skeleton with 20 carbon atoms. These dimers seem to

  18. Yttrium bismuth titanate pyrochlore mixed oxides for photocatalytic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Merka, Oliver

    2012-10-18

    In this work, the sol-gel synthesis of new non-stoichiometric pyrochlore titanates and their application in photocatalytic hydrogen production is reported. Visible light response is achieved by introducing bismuth on the A site or by doping the B site by transition metal cations featuring partially filled d orbitals. This work clearly focusses on atomic scale structural changes induced by the systematical introduction of non-stoichiometry in pyrochlore mixed oxides and the resulting influence on the activity in photocatalytic hydrogen production. The materials were characterized in detail regarding their optical properties and their atomic structure. The pyrochlore structure tolerates tremendous stoichiometry variations. The non-stoichiometry in A{sub 2}O{sub 3} rich compositions is compensated by distortions in the cationic sub-lattice for the smaller Y{sup 3+} cation and by evolution of a secondary phase for the larger Bi{sup 3+} cation on the A site. For TiO{sub 2} rich compositions, the non-stoichiometry leads to a special vacancy formation in the A and optionally O' sites. It is shown that pyrochlore mixed oxides in the yttrium bismuth titanate system represent very active and promising materials for photocatalytic hydrogen production, if precisely and carefully tuned. Whereas Y{sub 2}Ti{sub 2}O{sub 7} yields stable hydrogen production rates over time, the bismuth richer compounds of YBiTi{sub 2}O{sub 7} and Bi{sub 2}Ti{sub 2}O{sub 7} are found to be not stable under irradiation. This drawback is overcome by applying a special co-catalyst system consisting of a precious metal core and a Cr{sub 2}O{sub 3} shell on the photocatalysts.

  19. Wet oxidation pretreatment of rape straw for ethanol production

    International Nuclear Information System (INIS)

    Arvaniti, Efthalia; Bjerre, Anne Belinda; Schmidt, Jens Ejbye

    2012-01-01

    Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole slurry (Filter cake + filtrate) in SSF were also tested. Except ethanol yields, pretreatment methods were evaluated based on achieved glucose yields, amount of water used, recovery of cellulose, hemicellulose, and lignin. The highest ethanol yield obtained was 67% after fermenting the whole slurry produced by WO at 205 °C for 3 min with 12 bar of oxygen gas pressure and featured with presoaking in water. At these conditions after pre-treatment, cellulose and hemicellulose was recovered quantitatively (100%) together with 86% of the lignin. WO treatments of 2–3 min at 205–210 °C with 12 bar of oxygen gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid formation in SSF. -- Highlights: ► Wet Oxidation pretreatment on rape straw for sugar and ethanol production. ► Variables were reaction time, temperature, and oxygen gas pressure. ► Also, other configurations for increase of water and energy efficiency. ► Short Wet oxidation pretreatment (2–3 min) produced highest ethanol yield. ► After these pretreatment conditions recovery of lignin in solids was 86%.

  20. Solar Thermochemical Hydrogen Production via Terbium Oxide Based Redox Reactions

    Directory of Open Access Journals (Sweden)

    Rahul Bhosale

    2016-01-01

    Full Text Available The computational thermodynamic modeling of the terbium oxide based two-step solar thermochemical water splitting (Tb-WS cycle is reported. The 1st step of the Tb-WS cycle involves thermal reduction of TbO2 into Tb and O2, whereas the 2nd step corresponds to the production of H2 through Tb oxidation by water splitting reaction. Equilibrium compositions associated with the thermal reduction and water splitting steps were determined via HSC simulations. Influence of oxygen partial pressure in the inert gas on thermal reduction of TbO2 and effect of water splitting temperature (TL on Gibbs free energy related to the H2 production step were examined in detail. The cycle (ηcycle and solar-to-fuel energy conversion (ηsolar-to-fuel efficiency of the Tb-WS cycle were determined by performing the second-law thermodynamic analysis. Results obtained indicate that ηcycle and ηsolar-to-fuel increase with the decrease in oxygen partial pressure in the inert flushing gas and thermal reduction temperature (TH. It was also realized that the recuperation of the heat released by the water splitting reactor and quench unit further enhances the solar reactor efficiency. At TH=2280 K, by applying 60% heat recuperation, maximum ηcycle of 39.0% and ηsolar-to-fuel of 47.1% for the Tb-WS cycle can be attained.

  1. Cerium oxide nanoparticles stimulate proliferation of primary mouse embryonic fibroblasts in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Popov, Anton L., E-mail: antonpopovleonid@gmail.com [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region (Russian Federation); Popova, Nelly R. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region (Russian Federation); Selezneva, Irina I. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region (Russian Federation); Pushchino State Institute of Natural sciences, Pushchino, Moscow region (Russian Federation); Akkizov, Azamat Y. [Kabardino-Balkarian State University, Nalchik (Russian Federation); Ivanov, Vladimir K. [Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); National Research Tomsk State University, Tomsk (Russian Federation)

    2016-11-01

    The increasing application of cell therapy technologies in the treatment of various diseases requires the development of new effective methods for culturing primary cells. The major limitation for the efficient use of autologous cell material is the low rate of cell proliferation. Successful cell therapy requires sufficient amounts of cell material over a short period of time with the preservation of their differentiation and proliferative potential. In this regard, the development of novel, highly efficient stimulators of proliferative activity in stem cells is a truly urgent task. In this paper we have demonstrated that citrate-stabilized cerium oxide nanoparticles (nanoceria) enhance the proliferative activity of primary mouse embryonic fibroblasts in vitro. Cerium oxide nanoparticles stimulate cell proliferation in a wide range of concentrations (10{sup −3} M–10{sup −9} M) through reduction of intracellular levels of reactive oxygen species (ROS) during the lag phase of cell growth and by modulating the expression level of the major antioxidant enzymes. We found the optimal concentration of nanoceria, which provides the greatest acceleration of cell proliferation in vitro, while maintaining the levels of intracellular ROS and mRNA of antioxidant enzymes in the physiological range. Our results confirm that nanocrystalline ceria can be considered as a basis for effective and inexpensive supplements in cell culturing. - Highlights: • Citrate-stabilized cerium oxide nanoparticles are shown to stimulate proliferation of primary embryonic cells in vitro. • Some of mechanisms involved in stimulating of the proliferation by CeO{sub 2} have been uncovered. • The most effective (optimal) concentration of CeO{sub 2} nanoparticles for stimulation of proliferation was determined.

  2. Exhaled and nasal nitric oxide in chronic rhinosinusitis patients with nasal polyps in primary care

    DEFF Research Database (Denmark)

    Frendø, M; Håkansson, K; Schwer, S

    2018-01-01

    BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disorder associated with lower airway disease. However, only few studies of CRSwNP from outside secondary/tertiary care centres have been published. We recently reported an asthma frequency of 44% and 65...... patients. Compared with controls, a high level of exhaled NO was significantly more prevalent in CRSwNP irrespective of asthma-status. Nasal NO was significantly lower in patients with CRSwNP compared with controls. CONCLUSION: Subclinical eosinophilic lower airway inflammation is common in CRSwNP......% in primary and secondary care patients respectively. Therefore, we hypothesise that inflammation of the lower airways could be present in all CRSwNP patients, even without asthma. Here, we assessed the degree of lower and upper airway inflammation using exhaled and nasal nitric oxide (NO) in primary care...

  3. Primary production in the Bay of Bengal during southwest monsoon of 1978

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.; Devassy, V.P.; Radhakrishna, K.

    Measurements of primary production, chlorophyll a and particulate organic carbon were made at 33, 43 and 44 stations respectively during August-September of 1978. The average surface production, chlorophyll a and particulate organic carbon values...

  4. Primary Productivity, NASA Aqua MODIS and GOES Imager, 0.1 degrees, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from NASA Aqua MODIS Chl a and NOAA GOES Imager SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific...

  5. Primary Productivity, SeaWiFS and Pathfinder, 0.1 degrees, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from SeaWiFS Chl a, Pathfinder SST, and SeaWiFS PAR data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific...

  6. Primary Productivity, NASA Aqua MODIS, 4.4 km, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from NASA Aqua MODIS Chl a SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific evaluation by professional...

  7. The effect of natural antioxidants on the rate of accumulation of oxidation products in the fat phase of butter cream

    Directory of Open Access Journals (Sweden)

    M. S. Voronina

    2016-01-01

    Full Text Available Describes the main finishing prefabricated pastries and cakes-cream. Researched range of cream depending on the fruit components and method of production. Aim: to study the degree of oxidation cream with natural antioxidants from fruits and berries processing products, namely in the form of concentrated juice of fruits and berries. Outlines the process of oxidation of lipids, one of the fundamental processes of loss of quality food products. Describes the action of antioxidants as antioxidants on accumulation intensity concentrations of primary and secondary oxidation products, making the final product unsuitable for the consumer and the bounding its shelf life. Presents the results of a study of the contents of primary and secondary oxidation products in butter cream immediately after cooking, as well as samples, stored for five days with the addition of antioxidants in the form of concentrated juice of fruits and berries in the amount of 2–7% by weight of cream. As a control sample has been used cream with no additives. Quality indicators to characterize the degree of oxidation of the product: acid, peroxide, anizidin and tioburbit number. The study found that adding a concentrated juice of fruits and berries as antioxidant in recipe cream reduces the growth rate of the concentration of free fatty acids on the fifth day, as compared with the reference sample. Adding concentrated juice of fruits and berries slows down the process of dissolution of the fat molecules in fat fraction of cream with the formation of free fatty acids; intensity decay reaction of peroxides and hydroxides slows down and, consequently, decreases the formation of aldehydes, deteriorating the taste and smell of the cream; quantitatively reduced the growth of education malondial′degida.

  8. Nitrous oxide production kinetics during nitrate reduction in river sediments.

    Science.gov (United States)

    Laverman, Anniet M; Garnier, Josette A; Mounier, Emmanuelle M; Roose-Amsaleg, Céline L

    2010-03-01

    A significant amount of nitrogen entering river basins is denitrified in riparian zones. The aim of this study was to evaluate the influence of nitrate and carbon concentrations on the kinetic parameters of nitrate reduction as well as nitrous oxide emissions in river sediments in a tributary of the Marne (the Seine basin, France). In order to determine these rates, we used flow-through reactors (FTRs) and slurry incubations; flow-through reactors allow determination of rates on intact sediment slices under controlled conditions compared to sediment homogenization in the often used slurry technique. Maximum nitrate reduction rates (R(m)) ranged between 3.0 and 7.1microg Ng(-1)h(-1), and affinity constant (K(m)) ranged from 7.4 to 30.7mg N-NO(3)(-)L(-1). These values were higher in slurry incubations with an R(m) of 37.9microg Ng(-1)h(-1) and a K(m) of 104mg N-NO(3)(-)L(-1). Nitrous oxide production rates did not follow Michaelis-Menten kinetics, and we deduced a rate constant with an average of 0.7 and 5.4ng Ng(-1)h(-1) for FTR and slurry experiments respectively. The addition of carbon (as acetate) showed that carbon was not limiting nitrate reduction rates in these sediments. Similar rates were obtained for FTR and slurries with carbon addition, confirming the hypothesis that homogenization increases rates due to release of and increasing access to carbon in slurries. Nitrous oxide production rates in FTR with carbon additions were low and represented less than 0.01% of the nitrate reduction rates and were even negligible in slurries. Maximum nitrate reduction rates revealed seasonality with high potential rates in fall and winter and low rates in late spring and summer. Under optimal conditions (anoxia, non-limiting nitrate and carbon), nitrous oxide emission rates were low, but significant (0.01% of the nitrate reduction rates). Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Doxycycline reduces nitric oxide production in guinea pig inner ears.

    Science.gov (United States)

    Helling, Kai; Wodarzcyk, Karl; Brieger, Jürgen; Schmidtmann, Irene; Li, Huige; Mann, Wolf J; Heinrich, Ulf-Rüdiger

    2011-12-01

    Gentamicin application is an important therapeutic option to control vertigo spells in Ménière's disease. However, even in the case of low-dose intratympanic application, gentamicin might contribute to a pathological NO-increase leading to cochlear damage and hearing impairment. The study was performed to evaluate the nitric oxide (NO) reducing capacity of doxycycline in the inner ear after NO-induction by gentamicin. In a prospective animal study, a single dose of gentamicin (10mg/kg body weight) was injected intratympanically into male guinea pigs (n=48). The auditory brainstem responses (ABRs) were recorded prior to application and 3, 5 and 7 days afterwards. The organ of Corti and the lateral wall of 42 animals were isolated after 7 days and incubated separately for 6h in cell culture medium. Doxycycline was adjusted to organ cultures of 5 animals. Two NOS inhibitors, N(G)-Nitro-l-arginine methyl ester (l-NAME) and NG-monomethyl-l-arginine monoacetate (l-NMMA), were applied in three different concentrations to the organ cultures of 30 animals in total (5 animals per concentration). As controls, seven animals received no further substance except gentamicin. The NO-production was quantified by chemiluminescence. Additional six gentamicin-treated animals were used for immunohistochemical studies. The ABRs declined continuously from the first to the seventh day after gentamicin application. Doxycycline reduced NO-production in the lateral wall by 54% (p=.029) comparable to the effect of the applied nitric oxide inhibitors. In the organ of Corti, NO-production was reduced by about 41% showing no statistical significance in respect to great inter-animal variations. The application of doxycycline might offer a new therapeutic approach to prevent NO-induced cochlea damage through ototoxic substances. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Short-term to seasonal variability in factors driving primary productivity in a shallow estuary: Implications for modeling production

    Science.gov (United States)

    Canion, Andy; MacIntyre, Hugh L.; Phipps, Scott

    2013-10-01

    The inputs of primary productivity models may be highly variable on short timescales (hourly to daily) in turbid estuaries, but modeling of productivity in these environments is often implemented with data collected over longer timescales. Daily, seasonal, and spatial variability in primary productivity model parameters: chlorophyll a concentration (Chla), the downwelling light attenuation coefficient (kd), and photosynthesis-irradiance response parameters (Pmchl, αChl) were characterized in Weeks Bay, a nitrogen-impacted shallow estuary in the northern Gulf of Mexico. Variability in primary productivity model parameters in response to environmental forcing, nutrients, and microalgal taxonomic marker pigments were analysed in monthly and short-term datasets. Microalgal biomass (as Chla) was strongly related to total phosphorus concentration on seasonal scales. Hourly data support wind-driven resuspension as a major source of short-term variability in Chla and light attenuation (kd). The empirical relationship between areal primary productivity and a combined variable of biomass and light attenuation showed that variability in the photosynthesis-irradiance response contributed little to the overall variability in primary productivity, and Chla alone could account for 53-86% of the variability in primary productivity. Efforts to model productivity in similar shallow systems with highly variable microalgal biomass may benefit the most by investing resources in improving spatial and temporal resolution of chlorophyll a measurements before increasing the complexity of models used in productivity modeling.

  11. Modelling size-fractionated primary production in the Atlantic Ocean from remote sensing

    Science.gov (United States)

    Brewin, Robert J. W.; Tilstone, Gavin H.; Jackson, Thomas; Cain, Terry; Miller, Peter I.; Lange, Priscila K.; Misra, Ankita; Airs, Ruth L.

    2017-11-01

    Marine primary production influences the transfer of carbon dioxide between the ocean and atmosphere, and the availability of energy for the pelagic food web. Both the rate and the fate of organic carbon from primary production are dependent on phytoplankton size. A key aim of the Atlantic Meridional Transect (AMT) programme has been to quantify biological carbon cycling in the Atlantic Ocean and measurements of total primary production have been routinely made on AMT cruises, as well as additional measurements of size-fractionated primary production on some cruises. Measurements of total primary production collected on the AMT have been used to evaluate remote-sensing techniques capable of producing basin-scale estimates of primary production. Though models exist to estimate size-fractionated primary production from satellite data, these have not been well validated in the Atlantic Ocean, and have been parameterised using measurements of phytoplankton pigments rather than direct measurements of phytoplankton size structure. Here, we re-tune a remote-sensing primary production model to estimate production in three size fractions of phytoplankton (10 μm) in the Atlantic Ocean, using measurements of size-fractionated chlorophyll and size-fractionated photosynthesis-irradiance experiments conducted on AMT 22 and 23 using sequential filtration-based methods. The performance of the remote-sensing technique was evaluated using: (i) independent estimates of size-fractionated primary production collected on a number of AMT cruises using 14C on-deck incubation experiments and (ii) Monte Carlo simulations. Considering uncertainty in the satellite inputs and model parameters, we estimate an average model error of between 0.27 and 0.63 for log10-transformed size-fractionated production, with lower errors for the small size class (10 μm), and errors generally higher in oligotrophic waters. Application to satellite data in 2007 suggests the contribution of cells 2 μm to total

  12. Environmental conditions and primary production in a Sahelian ...

    African Journals Online (AJOL)

    Environmental descriptors (nutrient, water transparency, temperature ... Nutrient concentrations were low, with high variability (from 0 to 30 µg.l-1 for DIN and from 0 to 18 µg.l-1 for. PO4). The primary ... and permanent interventions of sea water.

  13. Distribution of phototrophic populations and primary production in a microbial mat from the Ebro Delta, Spain.

    Science.gov (United States)

    Martínez-Alonso, Maira; Mir, Joan; Caumette, Pierre; Gaju, Núria; Guerrero, Ricardo; Esteve, Isabel

    2004-03-01

    Microbial mats arising in the sand flats of the Ebro Delta (Tarragona, Spain) were investigated during the summer season, when the community was highly developed. These mats are composed of three pigmented layers of phototrophic organisms, an upper brown layer mainly composed of Lyngbya aestuarii and diatoms, an intermediate green layer of the cyanobacterium Microcoleus chthonoplastes, and an underlying pink layer of a so-far unidentified purple sulfur bacterium. In the photic zone, oxygenic phototrophs constitute about 58% of total photosynthetic biomass, measured as biovolume, and anoxygenic phototrophs represent 42%. Diatoms constitute 11.8% of the oxygenic biomass, M. chthonoplastes 61.2%, and L. aestuarii and coccoid cyanobacteria 20.6 and 6.4%, respectively. In this laminated community, organic matter has an autochthonous origin, and photosynthesis is the most important source of organic carbon. Oxygen production reaches up to 27.2 mmol O(2) m(-2) h(-1), measured at 1000 microE m(-2) s(-1) light intensity, whereas oxidation of sulfide in the light has been calculated to be 18.6 mmol S m(-2) h(-1). This amount represents 26% of the total photosynthetic production in terms of photoassimilated carbon, demonstrating the important role of anoxygenic phototrophs as primary producers in the pink layer of Ebro Delta microbial mats.

  14. Effect of the fast pyrolysis temperature on the primary and secondary products of lignin

    NARCIS (Netherlands)

    Zhou, Shuai; Garcia-Perez, Manuel; Pecha, Brennan; Kersten, Sascha R.A.; McDonald, Armando G.; Westerhof, Roel Johannes Maria

    2013-01-01

    This paper presents results on the primary pyrolysis products of organosolv lignin at temperatures between 360 and 700 °C. To study the primary products, a vacuum screen heater (heating rate of 8000 °C/s, deep vacuum of 0.7 mbar, and very fast cooling at the wall temperature of −100 °C) was used.

  15. Net primary productivity of subalpine meadows in Yosemite National Park in relation to climate variability

    Science.gov (United States)

    Peggy E. Moore; Jan W. van Wagtendonk; Julie L. Yee; Mitchel P. McClaran; David N. Cole; Neil K. McDougald; Matthew L. Brooks

    2013-01-01

    Subalpine meadows are some of the most ecologically important components of mountain landscapes, and primary productivity is important to the maintenance of meadow functions. Understanding how changes in primary productivity are associated with variability in moisture and temperature will become increasingly important with current and anticipated changes in climate....

  16. Primary production, nutrient dynamics and mineralisation in a northeastern Greenland fjord during the summer thaw

    DEFF Research Database (Denmark)

    Rysgaard, S.; Finster, K.; Dahlgaard, H.

    1996-01-01

    This investigation represents the first integrated study of primary production, nutrient dynamics and mineralisation in a northeastern fjord of Greenland. The data presented represent conditions and activities during the early summer thaw (first 2 weeks of July). Primary production (5.3 mmol C m(...

  17. Micro-phytoplankton photosynthesis, primary production and potential export production in the Atlantic Ocean

    Science.gov (United States)

    Tilstone, Gavin H.; Lange, Priscila K.; Misra, Ankita; Brewin, Robert J. W.; Cain, Terry

    2017-11-01

    Micro-phytoplankton is the >20 μm component of the phytoplankton community and plays a major role in the global ocean carbon pump, through the sequestering of anthropogenic CO2 and export of organic carbon to the deep ocean. To evaluate the global impact of the marine carbon cycle, quantification of micro-phytoplankton primary production is paramount. In this paper we use both in situ data and a satellite model to estimate the contribution of micro-phytoplankton to total primary production (PP) in the Atlantic Ocean. From 1995 to 2013, 940 measurements of primary production were made at 258 sites on 23 Atlantic Meridional Transect Cruises from the United Kingdom to the South African or Patagonian Shelf. Micro-phytoplankton primary production was highest in the South Subtropical Convergence (SSTC ∼ 409 ± 720 mg C m-2 d-1), where it contributed between 38 % of the total PP, and was lowest in the North Atlantic Gyre province (NATL ∼ 37 ± 27 mg C m-2 d-1), where it represented 18 % of the total PP. Size-fractionated photosynthesis-irradiance (PE) parameters measured on AMT22 and 23 showed that micro-phytoplankton had the highest maximum photosynthetic rate (PmB) (∼5 mg C (mg Chl a)-1 h-1) followed by nano- (∼4 mg C (mg Chl a)-1 h-1) and pico- (∼2 mg C (mg Chl a)-1 h-1). The highest PmB was recorded in the NATL and lowest in the North Atlantic Drift Region (NADR) and South Atlantic Gyre (SATL). The PE parameters were used to parameterise a remote sensing model of size-fractionated PP, which explained 84 % of the micro-phytoplankton in situ PP variability with a regression slope close to 1. The model was applied to the SeaWiFS time series from 1998-2010, which illustrated that micro-phytoplankton PP remained constant in the NADR, NATL, Canary Current Coastal upwelling (CNRY), Eastern Tropical Atlantic (ETRA), Western Tropical Atlantic (WTRA) and SATL, but showed a gradual increase in the Benguela Upwelling zone (BENG) and South Subtropical Convergence (SSTC

  18. Can the primary algae production be measured precisely?

    International Nuclear Information System (INIS)

    Olesen, M.; Lundsgaard, C.

    1996-01-01

    Algae production in seawater is extremely important as a basic link in marine food chains. Evaluation of the algae quantity is based on 14CO 2 tracer techniques while natural circulation and light absorption in seawater is taken insufficiently into account. Algae production can vary by 500% in similar nourishment conditions, but varying water mixing conditions. (EG)

  19. Linking climate, gross primary productivity, and site index across forests of the western United States

    Science.gov (United States)

    Aaron R. Weiskittel; Nicholas L. Crookston; Philip J. Radtke

    2011-01-01

    Assessing forest productivity is important for developing effective management regimes and predicting future growth. Despite some important limitations, the most common means for quantifying forest stand-level potential productivity is site index (SI). Another measure of productivity is gross primary production (GPP). In this paper, SI is compared with GPP estimates...

  20. Yields of primary products from chloroethylenes in air under electron beam irradiation

    International Nuclear Information System (INIS)

    Hakoda, Teruyuki; Hashimoto, Shoji; Kojima, Takuji

    2003-01-01

    The quantitative analysis of toxic primary irradiation products was carried out for the development of the purification technology of chloroethylenes/air mixtures using an electron beam (EB). Degradation of chloroethylenes in humid air proceeded through the formation of primary products retaining a carbon-carbon (C-C) bond such as chloroacetyl chlorides and chloroacetyl aldehyde as well as that of primary products of COCl 2 and HCOCl through C-C bond cleavage. Chloroethylenes having one carbon bonded to two Cl atoms was decomposed into the primary products retaining a C-C bond prior to breaking a C-C bond. The number of Cl atoms of a chloroethylene molecule enhanced the formation ratio of primary products retaining a C-C bond. On the other hand, chloroethylene having two carbons bonded to one Cl atom was degraded thought the scission of a C-C bond predominantly C-C bond maintenance. (author)

  1. Efficient production of ultrapure manganese oxides via electrodeposition.

    Science.gov (United States)

    Cheney, Marcos A; Joo, Sang Woo; Banerjee, Arghya; Min, Bong-Ki

    2012-08-01

    A new process for the production of electrolytic amorphous nanomanganese oxides (EAMD) with uniform size and morphology is described. EAMD are produced for the first time by cathodic deposition from a basic aqueous solution of potassium permanganate at a constant temperature of 16°C. The synthesized materials are characterized by XRD, SEM, TEM, and HRTEM. The materials produced at 5.0 V at constant temperature are amorphous with homogeneous size and morphology with an average particle size around 20 nm, which appears to be much lesser than the previously reported anodic EAMD. A potentiostatic electrodeposition with much lesser deposition rate (with respect to previously reported anodic depositions) is considered to be the reason behind the very low and homogenous particle size distribution due to the lesser agglomeration of our as-synthesized nanoparticles. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Production of zinc oxide nanowires power with precisely defined morphology

    Science.gov (United States)

    Mičová, Júlia; Remeš, Zdeněk; Chan, Yu-Ying

    2017-12-01

    The interest about zinc oxide is increasing thanks to its unique chemical and physical properties. Our attention has focused on preparation powder of 1D nanostructures of ZnO nanowires with precisely defined morphology include characterization size (length and diameter) and shape controlled in the scanning electron microscopy (SEM). We have compared results of SEM with dynamic light scattering (DLS) technique. We have found out that SEM method gives more accurate results. We have proposed transformation process from ZnO nanowires on substrates to ZnO nanowires powder by ultrasound peeling to colloid followed by lyophilization. This method of the mass production of the ZnO nanowires powder has some advantages: simplicity, cost effective, large-scale and environment friendly.

  3. Wet oxidation pretreatment of rape straw for ethanol production

    DEFF Research Database (Denmark)

    Arvaniti, Efthalia; Bjerre, Anne Belinda; Schmidt, Jens Ejbye

    2012-01-01

    Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via...... Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole...... gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid...

  4. PROMOTION OF PRIMARY PRODUCTS - A VIEW FROM THE CLOISTER

    OpenAIRE

    Quilkey, John J.

    1986-01-01

    This paper is a discourse on how promotion may contribute to the efficiency of consumption. The view is taken that, through its addition to the quantity of search with respect to product characteristics, promotion may enable consumers to allocate their expenditures more efficiently and yield additional revenue to producers of the promoted product. The central plea is for consistency in the identification of promotion objectives, the implementation of the promotion program and monitoring of th...

  5. Global resistance and resilience of primary production following extreme drought are predicted by mean annual precipitation

    Science.gov (United States)

    Stuart-Haëntjens, E. J.; De Boeck, H. J.; Lemoine, N. P.; Gough, C. M.; Kröel-Dulay, G.; Mänd, P.; Jentsch, A.; Schmidt, I. K.; Bahn, M.; Lloret, F.; Kreyling, J.; Wohlgemuth, T.; Stampfli, A.; Anderegg, W.; Classen, A. T.; Smith, M. D.

    2017-12-01

    Extreme drought is increasing globally in frequency and intensity, with uncertain consequences for the resistance and resilience of key ecosystem functions, including primary production. Primary production resistance, the capacity of an ecosystem to withstand change in primary production following extreme climate, and resilience, the degree to which primary production recovers, vary among and within ecosystem types, obscuring global patterns of resistance and resilience to extreme drought. Past syntheses on resistance have focused climatic gradients or individual ecosystem types, without assessing interactions between the two. Theory and many empirical studies suggest that forest production is more resistant but less resilient than grassland production to extreme drought, though some empirical studies reveal that these trends are not universal. Here, we conducted a global meta-analysis of sixty-four grassland and forest sites, finding that primary production resistance to extreme drought is predicted by a common continuum of mean annual precipitation (MAP). However, grasslands and forests exhibit divergent production resilience relationships with MAP. We discuss the likely mechanisms underlying the mixed production resistance and resilience patterns of forests and grasslands, including different plant species turnover times and drought adaptive strategies. These findings demonstrate the primary production responses of forests and grasslands to extreme drought are mixed, with far-reaching implications for Earth System Models, ecosystem management, and future studies of extreme drought resistance and resilience.

  6. Production of biogenic manganese oxides coupled with methane oxidation in a bioreactor for removing metals from wastewater.

    Science.gov (United States)

    Matsushita, Shuji; Komizo, Daisuke; Cao, Linh Thi Thuy; Aoi, Yoshiteru; Kindaichi, Tomonori; Ozaki, Noriatsu; Imachi, Hiroyuki; Ohashi, Akiyoshi

    2018-03-01

    Biogenic manganese oxide (BioMnO x ) can efficiently adsorb various minor metals. The production of BioMnO x in reactors to remove metals during wastewater treatment processes is a promising biotechnological method. However, it is difficult to preferentially enrich manganese-oxidizing bacteria (MnOB) to produce BioMnO x during wastewater treatment processes. A unique method of cultivating MnOB using methane-oxidizing bacteria (MOB) to produce soluble microbial products is proposed here. MnOB were successfully enriched in a methane-fed reactor containing MOB. BioMnO x production during the wastewater treatment process was confirmed. Long-term continual operation of the reactor allowed simultaneous removal of Mn(II), Co(II), and Ni(II). The Co(II)/Mn(II) and Ni(II)/Mn(II) removal ratios were 53% and 19%, respectively. The degree to which Mn(II) was removed indicated that the enriched MnOB used utilization-associated products and/or biomass-associated products. Microbial community analysis revealed that methanol-oxidizing bacteria belonging to the Hyphomicrobiaceae family played important roles in the oxidation of Mn(II) by using utilization-associated products. Methane-oxidizing bacteria were found to be inhibited by MnO 2 , but the maximum Mn(II) removal rate was 0.49 kg m -3  d -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Scaling Gross Primary Production (GPP) over boreal and deciduous forest landscapes in support of MODIS GPP product validation.

    Science.gov (United States)

    David P. Turner; William D. Ritts; Warren B. Cohen; Stith T. Gower; Maosheng Zhao; Steve W. Running; Steven C. Wofsy; Shawn Urbanski; Allison L. Dunn; J.W. Munger

    2003-01-01

    The Moderate Resolution Imaging Radiometer (MODIS) is the primary instrument in the NASA Earth Observing System for monitoring the seasonality of global terrestrial vegetation. Estimates of 8-day mean daily gross primary production (GPP) at the 1 km spatial resolution are now operationally produced by the MODIS Land Science Team for the global terrestrial surface using...

  8. Proposition of primary methods for nitrogen oxides emissions reduction at coal-fired 200 MW power unit (Yugoslavia)

    International Nuclear Information System (INIS)

    Repic, B.; Mladenovic, R.; Crnomarkovic, N.

    1997-01-01

    The combustion of coal is followed by increased pollution of the environment with toxic products. Together with the generation of other pollutants, the emission of nitrogen oxides (NO x ) represents, due to its high toxicity, a great environmental risk. Appropriate measures must be taken for lowering NO x emission, both on new facilities and those already in operation. Basic technologies (primary reduction methods) of several generations, developed until now and used in practice, are presented in the paper. The technologies applicable on domestic facilities and adjusted to domestic coals have been given particular consideration. Proposition of primary methods for NO x emission reduction at coal-fired 200 MW power unit at TPS 'Nikola Tesla' is analyzed. The following methods have been considered in detail: flue gases recirculation, multi-stage combustion, low-NO x burners, additional over-fire air, multi-stage air intake into the furnace, staged fuel injection, grinding fineness increase, etc. Considerations were performed according to existing constructive characteristics of the furnace and the burners, and characteristics of used fuels, i. e. lignites from Kolubara pit. (Author)

  9. Primary defect production by high energy displacement cascades in molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Selby, Aaron P. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Xu, Donghua, E-mail: xudh@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Juslin, Niklas; Capps, Nathan A. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Oak Ridge National Laboratory, P.O. Box 2008, MS6003, Oak Ridge, TN 37831 (United States)

    2013-06-15

    We report molecular dynamics simulations of primary damage in molybdenum produced by high energy displacement cascades on the femto- to pico-second and Angstrom to nanometer scales. Clustering directly occurred for both interstitials and vacancies in the 1–50 keV cascade energy range explored. Point defect survival efficiency and partitioning probabilities into different sized clusters were quantified. The results will provide an important reference for kinetic models to describe the microstructural evolution in Mo under ion or neutron irradiations over much longer time and length scales.

  10. Healthy Dietary Patterns and Oxidative Stress as Measured by Fluorescent Oxidation Products in Nurses’ Health Study

    Directory of Open Access Journals (Sweden)

    Seungyoun Jung

    2016-09-01

    Full Text Available Healthy diets may lower oxidative stress and risk of chronic diseases. However, no previous studies examined associations between diet and fluorescent oxidation products (FlOP, a global marker of oxidative stress. We evaluated associations between healthy eating patterns (Alternative Healthy Eating Index (AHEI, Dietary Approach to Stop Hypertension (DASH, and Alternate Mediterranean Diet (aMED and FlOP, measured at three excitation/emission wavelengths (FlOP_360, FlOP_320, FlOP_400 from 2021 blood samples collected from 1688 women within the Nurses’ Health Study. AHEI, DASH, and aMED scores were significantly positively associated with FlOP_360 and FlOP_320 concentrations (p-trend ≤ 0.04, but not associated with FlOP_400. Among specific food groups that contribute to these diet scores, significantly positive associations were observed with legumes and vegetables for FlOP_360, vegetables and fruits for FlOP_320, and legumes and alcohol for FlOP_400. Inverse associations were observed with nuts, sweets or desserts, and olive oil for FlOP_360, nuts for FlOP_320 and sweets or desserts for FlOP_400 (all p-trend ≤ 0.05. However, FlOP variation due to diet was small compared to overall FlOP variation. In conclusion, AHEI, DASH, and aMED scores were unexpectedly positively, but weakly, associated with FlOP_360 and FlOP_320. However, these findings should be interpreted cautiously as the determinants of FlOP concentrations are not fully understood.

  11. Healthy Dietary Patterns and Oxidative Stress as Measured by Fluorescent Oxidation Products in Nurses' Health Study.

    Science.gov (United States)

    Jung, Seungyoun; Smith-Warner, Stephanie A; Willett, Walter C; Wang, Molin; Wu, Tianying; Jensen, Majken; Hankinson, Susan E; Eliassen, A Heather

    2016-09-21

    Healthy diets may lower oxidative stress and risk of chronic diseases. However, no previous studies examined associations between diet and fluorescent oxidation products (FlOP), a global marker of oxidative stress. We evaluated associations between healthy eating patterns (Alternative Healthy Eating Index (AHEI), Dietary Approach to Stop Hypertension (DASH), and Alternate Mediterranean Diet (aMED)) and FlOP, measured at three excitation/emission wavelengths (FlOP_360, FlOP_320, FlOP_400) from 2021 blood samples collected from 1688 women within the Nurses' Health Study. AHEI, DASH, and aMED scores were significantly positively associated with FlOP_360 and FlOP_320 concentrations ( p -trend ≤ 0.04), but not associated with FlOP_400. Among specific food groups that contribute to these diet scores, significantly positive associations were observed with legumes and vegetables for FlOP_360, vegetables and fruits for FlOP_320, and legumes and alcohol for FlOP_400. Inverse associations were observed with nuts, sweets or desserts, and olive oil for FlOP_360, nuts for FlOP_320 and sweets or desserts for FlOP_400 (all p -trend ≤ 0.05). However, FlOP variation due to diet was small compared to overall FlOP variation. In conclusion, AHEI, DASH, and aMED scores were unexpectedly positively, but weakly, associated with FlOP_360 and FlOP_320. However, these findings should be interpreted cautiously as the determinants of FlOP concentrations are not fully understood.

  12. Nitrous oxide production associated with coastal marine invertebrates

    DEFF Research Database (Denmark)

    Heisterkamp, Ines Maria; Schramm, Andreas; de Beer, Dirk

    2010-01-01

    Several freshwater and terrestrial invertebrate species emit the greenhouse gas nitrous oxide (N2O). The N2O production associated with these animals was ascribed to incomplete denitrification by ingested sediment or soil bacteria. The present study shows that many marine invertebrates also emit N2......O at substantial rates. A total of 19 invertebrate species collected in the German Wadden Sea and in Aarhus Bay, Denmark, and 1 aquacultured shrimp species were tested for N2O emission. Potential N2O emission rates ranged from 0 to 1.354 nmol ind.–1 h–1, with an average rate of 0.320 nmol ind.–1 h–1...... with an experimentally cleaned shell. Thus, the N2O production associated with marine invertebrates is apparently not due to gut denitrification in every species, but may also result from microbial activity on the external surfaces of animals. The high abundance and potential N2O emission rates of many marine...

  13. Durability of solid oxide electrolysis cells for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Hauch, A.; Hoejgaard Jensen, S.; Dalgaard Ebbesen, S.

    2007-05-15

    In the perspective of the increasing interest in renewable energy and hydrogen economy, the reversible solid oxide cells (SOCs) is a promising technology as it has the potential of providing efficient and cost effective hydrogen production by high temperature electrolysis of steam (HTES). Furthermore development of such electrolysis cells can gain from the results obtained within the R and D of SOFCs. For solid oxide electrolysis cells (SOEC) to become interesting from a technological point of view, cells that are reproducible, high performing and long-term stable need to be developed. In this paper we address some of the perspectives of the SOEC technology i.e. issues such as a potential H2 production price as low as 0.71 US dollar/kg H{sub 2} using SOECs for HTES; is there a possible market for the electrolysers? and what R and D steps are needed for the realisation of the SOEC technology? In the experimental part we present electrolysis test results on SOCs that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre-pilot scale at Risoe National Laboratory. These cells have been shown to have excellent initial electrolysis performance, but the durability of such electrolysis cells are not optimal and examples of results from SOEC tests over several hundreds of hours are given here. The long-term tests have been run at current densities of -0.5 A/cm{sup 2} and -1 A/cm{sup 2}, temperatures of 850 deg. C and 950 deg. C and p(H{sub 2}O)/p(H{sub 2}) of 0.5/0.5 and 0.9/0.1. Long-term degradation rates are shown to be up to 5 times higher for SOECs compared to similar SOFC testing. Furthermore, hydrogen and synthetic fuel production prices are calculated using the experimental results from long-term electrolysis test as input and a short outlook for the future work on SOECs will be given as well. (au)

  14. Gross nitrous oxide production drives net nitrous oxide fluxes across a salt marsh landscape.

    Science.gov (United States)

    Yang, Wendy H; Silver, Whendee L

    2016-06-01

    Sea level rise will change inundation regimes in salt marshes, altering redox dynamics that control nitrification - a potential source of the potent greenhouse gas, nitrous oxide (N2 O) - and denitrification, a major nitrogen (N) loss pathway in coastal ecosystems and both a source and sink of N2 O. Measurements of net N2 O fluxes alone yield little insight into the different effects of redox conditions on N2 O production and consumption. We used in situ measurements of gross N2 O fluxes across a salt marsh elevation gradient to determine how soil N2 O emissions in coastal ecosystems may respond to future sea level rise. Soil redox declined as marsh elevation decreased, with lower soil nitrate and higher ferrous iron in the low marsh compared to the mid and high marshes (P production was highest in the low marsh and lowest in the mid-marsh (P = 0.02), whereas gross N2 O consumption did not differ among marsh zones. Thus, variability in gross N2 O production rates drove the differences in net N2 O flux among marsh zones. Our results suggest that future studies should focus on elucidating controls on the processes producing, rather than consuming, N2 O in salt marshes to improve our predictions of changes in net N2 O fluxes caused by future sea level rise. © 2015 John Wiley & Sons Ltd.

  15. GHG emissions from primary aluminum production in China: Regional disparity and policy implications

    International Nuclear Information System (INIS)

    Hao, Han; Geng, Yong; Hang, Wen

    2016-01-01

    Highlights: • GHG emissions from primary aluminum production in China were accounted. • The impact of regional disparity of power generation was considered for this study. • GHG emissions factor of China’s primary aluminum production was 16.5 t CO_2e/t Al ingot in 2013. • Total GHG emissions from China’s primary aluminum production were 421 mt CO_2e in 2013. - Abstract: China is the world-leading primary aluminum production country, which contributed to over half of global production in 2014. Primary aluminum production is power-intensive, for which power generation has substantial impact on overall Greenhouse Gas (GHG) emissions. In this study, we explore the impact of regional disparity of China’s power generation system on GHG emissions for the sector of primary aluminum production. Our analysis reveals that the national GHG emissions factor (GEF) of China’s primary aluminum production was 16.5 t CO_2e/t Al ingot in 2013, with province-level GEFs ranging from 8.2 to 21.7 t CO_2e/t Al ingot. There is a high coincidence of provinces with high aluminum productions and high GEFs. Total GHG emissions from China’s primary aluminum production were 421 mt CO_2e in 2013, approximately accounting for 4% of China’s total GHG emissions. Under the 2020 scenario, GEF shows a 13.2% reduction compared to the 2013 level, but total GHG emissions will increase to 551 mt CO_2e. Based on our analysis, we recommend that the government should further promote energy efficiency improvement, facilitate aluminum industry redistribution with low-carbon consideration, promote secondary aluminum production, and improve aluminum industry data reporting and disclosure.

  16. Sensible use of primary energy in organic greenhouse production

    NARCIS (Netherlands)

    Stanghellini, C.; Baptista, F.; Eriksson, Evert; Gilli, Celine; Giuffrida, F.; Kempkes, F.L.K.; Munoz, P.; Stepowska, Agnieszka; Montero, J.I.

    2016-01-01

    Review of the major sources for energy consumption in organic greenhouse horticulture and analyse of the options available to reduce energy consumption or, at least, increase the energy use efficiency of organic production in greenhouses. At the moment, the best way to match demand and availability

  17. Computing the Net Primary Productivity for a Savanna- Dominated ...

    African Journals Online (AJOL)

    komla

    2003-05-19

    May 19, 2003 ... productivity of CO2 (between 1–2% per year) continues, a doubling of the CO2 ... The work ... Numerous isotope mass balance equa-tions are proposed to ..... Terrestrial ecoregions of the world: a new map of life on earth.

  18. Sustainable Production of Asphalt using Biomass as Primary Process Fuel

    DEFF Research Database (Denmark)

    Bühler, Fabian; Nguyen, Tuong-Van; Elmegaard, Brian

    2016-01-01

    is the heating and drying of aggregate,where natural gas, fuel oil or LPG is burned in a direct-fired rotary dryer. Replacing this energy source with amore sustainable one presents several technical and economic challenges, as high temperatures, short startuptimes and seasonal production variations are required...

  19. Products of tungstate ion interaction with primary aliphatic amines

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Sejfullina, I.I.; Purich, A.N.; Babinets, S.K.

    1982-01-01

    Using the methods of conductometric titration, IR-spectroscopic and thermographic analyses precipitates formed in the process of interaction of diluted aqueous solutions of sodium tungstate with alcoholic solutions of dodecyl-, tetradecyl- and octadecylamine have been studied. It is shown that as a result of interaction tungstates of corresponding amines are formed. The structure and thermal stability of singled out products are determined

  20. Volatile profile, lipid oxidation and protein oxidation of irradiated ready-to-eat cured turkey meat products

    International Nuclear Information System (INIS)

    Feng, Xi; Ahn, Dong Uk

    2016-01-01

    Irradiation had little effects on the thiobarbituric acid reactive substances (TBARS) values in ready-to-eat (RTE) turkey meat products, while it increased protein oxidation at 4.5 kGy. The volatile profile analyses indicated that the amount of sulfur compounds increased linearly as doses increased in RTE turkey meat products. By correlation analysis, a positive correlation was found between benzene/ benzene derivatives and alcohols with lipid oxidation, while aldehydes, ketones and alkane, alkenes and alkynes were positively correlated with protein oxidation. Principle component analysis showed that irradiated meat samples can be discriminated by two categories of volatile compounds: Strecker degradation products and radiolytic degradation products. The cluster analysis of volatile data demonstrated that low-dose irradiation had minor effects on the volatile profile of turkey sausages (<1.5 kGy). However, as the doses increased, the differences between the irradiated and non-irradiated cured turkey products became significant. - Highlights: • Irradiation had little effects on lipid oxidation of ready-to-eat cured turkey. • 4.5 kGy irradiation increased protein oxidation. • Irradiated samples were isolated due to Strecker/radiolytic degradation products. • 1.5 kGy irradiation had limited effects on the volatile profile of turkey sausages. • Dimethyl disulfide can be used as a potential marker for irradiated meat products.

  1. Interannual Variation in Phytoplankton Class-Specific Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile Severine; Gregg, Watson W.

    2014-01-01

    We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. First we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms were the group that contributed the most to the total phytoplankton production (50, the equivalent of 20 PgC y-1. Coccolithophores and chlorophytes each contributed to 20 (7 PgC y-1 of the total primary production and cyanobacteria represented about 10 (4 PgC y(sub-1) of the total primary production. Primary production by diatoms was highest in high latitude (45) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4 (1-2 PgC y-1. We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nio Index, MEI) and regional climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p 0.05) between the MEI and the class-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatomscyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect on the class-specific primary production in the Southern Ocean. These results provide a modeling and

  2. Strategies to mitigate nitrous oxide emissions from herbivore production systems.

    Science.gov (United States)

    Schils, R L M; Eriksen, J; Ledgard, S F; Vellinga, Th V; Kuikman, P J; Luo, J; Petersen, S O; Velthof, G L

    2013-03-01

    Herbivores are a significant source of nitrous oxide (N(2)O) emissions. They account for a large share of manure-related N(2)O emissions, as well as soil-related N(2)O emissions through the use of grazing land, and land for feed and forage production. It is widely acknowledged that mitigation measures are necessary to avoid an increase in N(2)O emissions while meeting the growing global food demand. The production and emissions of N(2)O are closely linked to the efficiency of nitrogen (N) transfer between the major components of a livestock system, that is, animal, manure, soil and crop. Therefore, mitigation options in this paper have been structured along these N pathways. Mitigation technologies involving diet-based intervention include lowering the CP content or increasing the condensed tannin content of the diet. Animal-related mitigation options also include breeding for improved N conversion and high animal productivity. The main soil-based mitigation measures include efficient use of fertilizer and manure, including the use of nitrification inhibitors. In pasture-based systems with animal housing facilities, reducing grazing time is an effective option to reduce N(2)O losses. Crop-based options comprise breeding efforts for increased N-use efficiency and the use of pastures with N(2)-fixing clover. It is important to recognize that all N(2)O mitigation options affect the N and carbon cycles of livestock systems. Therefore, care should be taken that reductions in N(2)O emissions are not offset by unwanted increases in ammonia, methane or carbon dioxide emissions. Despite the abundant availability of mitigation options, implementation in practice is still lagging. Actual implementation will only follow after increased awareness among farmers and greenhouse gases targeted policies. So far, reductions in N(2)O emissions that have been achieved are mostly a positive side effect of other N-targeted policies.

  3. A model of regional primary production for use with coarse resolution satellite data

    Science.gov (United States)

    Prince, S. D.

    1991-01-01

    A model of crop primary production, which was originally developed to relate the amount of absorbed photosynthetically active radiation (APAR) to net production in field studies, is discussed in the context of coarse resolution regional remote sensing of primary production. The model depends on an approximately linear relationship between APAR and the normalized difference vegetation index. A more comprehensive form of the conventional model is shown to be necessary when different physiological types of plants or heterogeneous vegetation types occur within the study area. The predicted variable in the new model is total assimilation (net production plus respiration) rather than net production alone or harvest yield.

  4. Calculation model for predicting concentrations of radioactive corrostion products in the primary coolant of boiling water reactors

    International Nuclear Information System (INIS)

    Uchida, S.; Kikuchi, M.; Asakura, Y.; Yusa, H.; Ohsumi, K.

    1978-01-01

    A calculation model was developed to predict the shutdown dose rate around the recirculation pipes and their components in boiling water reactors (BWRs) by simulating the corrosion product transport in primary cooling water. The model is characterized by separating cobalt species in the water into soluble and insoluble materials and then calculating each concentration using the following considerations: (1) Insoluble cobalt (designated as crud cobalt is deposited directly on the fuel surface, while soluble cobalt (designated as ionic cobalt) is adsorbed on iron oxide deposits on the fuel surface. (2) Cobalt-60 activated on the fuel surface is dissolved in the water in an ionic form, and some is released with iron oxide as crud. The model can follow the reduction of 60 Co in the primary cooling water caused by the control of the iron feed rate into the reactor, which decreases the iron oxide deposits on the fuel surface and then reduces the cobalt adsorption rate. The calculated results agree satisfactorily with the measurements in several BWR plants

  5. Neuroprotective Effect of Carnosine on Primary Culture of Rat Cerebellar Cells under Oxidative Stress.

    Science.gov (United States)

    Lopachev, A V; Lopacheva, O M; Abaimov, D A; Koroleva, O V; Vladychenskaya, E A; Erukhimovich, A A; Fedorova, T N

    2016-05-01

    Dipeptide carnosine (β-alanyl-L-histidine) is a natural antioxidant, but its protective effect under oxidative stress induced by neurotoxins is studied insufficiently. In this work, we show the neuroprotective effect of carnosine in primary cultures of rat cerebellar cells under oxidative stress induced by 1 mM 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH), which directly generates free radicals both in the medium and in the cells, and 20 nM rotenone, which increases the amount of intracellular reactive oxygen species (ROS). In both models, adding 2 mM carnosine to the incubation medium decreased cell death calculated using fluorescence microscopy and enhanced cell viability estimated by the MTT assay. The antioxidant effect of carnosine inside cultured cells was demonstrated using the fluorescence probe dichlorofluorescein. Carnosine reduced by half the increase in the number of ROS in neurons induced by 20 nM rotenone. Using iron-induced chemiluminescence, we showed that preincubation of primary neuronal cultures with 2 mM carnosine prevents the decrease in endogenous antioxidant potential of cells induced by 1 mM AAPH and 20 nM rotenone. Using liquid chromatography-mass spectrometry, we showed that a 10-min incubation of neuronal cultures with 2 mM carnosine leads to a 14.5-fold increase in carnosine content in cell lysates. Thus, carnosine is able to penetrate neurons and exerts an antioxidant effect. Western blot analysis revealed the presence of the peptide transporter PEPT2 in rat cerebellar cells, which suggests the possibility of carnosine transport into the cells. At the same time, Western blot analysis showed no carnosine-induced changes in the level of apoptosis regulating proteins of the Bcl-2 family and in the phosphorylation of MAP kinases, which suggests that carnosine could have minimal or no side effects on proliferation and apoptosis control systems in normal cells.

  6. Effects of PbO on the oxide films of incoloy 800HT in simulated primary circuit of PWR

    International Nuclear Information System (INIS)

    Tan, Yu; Yang, Junhan; Wang, Wanwan; Shi, Rongxue; Liang, Kexin; Zhang, Shenghan

    2016-01-01

    Effects of trace PbO on oxide films of Incoloy 800HT were investigated in simulated primary circuit water chemistry of PWR, also with proper Co addition. The trace PbO addition in high temperature water blocked the protective spinel oxides formation of the oxide films of Incoloy 800HT. XPS results indicated that the lead, added as PbO into the high temperature water, shows not only +2 valance but also +4 and 0 valances in the oxide film of 800HT co-operated with Fe, Cr and Ni to form oxides films. Potentiodynamic polarization results indicated that as PbO concentration increased, the current densities of the less protective oxide films of Incoloy 800HT decreased in a buffer solution tested at room temperature. The capacitance results indicated that the donor densities of oxidation film of Incoloy 800HT decreased as trace PbO addition into the high temperature water. - Highlights: • Trace PbO addition into the high temperature water block the formation of spinel oxides on Incoloy 800HT. • The donor density of oxide film decreases with trace PbO addition. • The current density of potentiodynamic polarization decreases of oxide film with trace PbO addition.

  7. Interannual Variation in Phytoplankton Class-specific Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile; Gregg, Watson

    2014-01-01

    Phytoplankton is responsible for over half of the net primary production on earth. The knowledge on the contribution of various phytoplankton groups to the total primary production is still poorly understood. Data from satellite observations suggest that for upwelling regions, photosynthetic rates by microplankton is higher than that of nanoplankton but that when the spatial extent is considered, the production by nanoplankton is comparable or even larger than microplankton. Here, we used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. Globally, diatoms were the group that contributed the most to the total phytoplankton production (approx. 50%) followed by coccolithophores and chlorophytes. Primary production by diatoms was highest in high latitude (>45 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nino Index, MEI) and 'regional' climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability. These results provide a modeling and data assimilation perspective to phytoplankton partitioning of primary production and contribute to our understanding of the dynamics of the carbon cycle in the oceans at a global scale.

  8. Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments

    Czech Academy of Sciences Publication Activity Database

    Wilcox, K. R.; Shi, Z.; Gherardi, L. A.; Lemoine, N. P.; Koerner, S. E.; Hoover, D. L.; Bork, E.; Byrne, K. M.; Cahill, J.; Collins, S. L.; Evans, S.M.; Gilgen, Anna K.; Holub, Petr; Jiang, L.; Knapp, A. K.; LeCain, D.; Liang, J.; Garcia-Palacios, P.; Penuelas, J.; Pockman, W. T.; Smith, M. D.; Sun, S.; White, S. R.; Yahdjian, L.; Zhu, K.; Luo, Y.

    2017-01-01

    Roč. 23, č. 10 (2017), s. 4376-4385 ISSN 1354-1013 Institutional support: RVO:86652079 Keywords : net primary productivity * terrestrial ecosystems * temperate grassland * biomass allocation * plant-communities * tallgrass prairie * climate extremes * use efficiency * united-states * global-change * aboveground net primary productivity * belowground net primary productivity * biomass allocation * climate change * grasslands * meta-analysis * root biomass Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 8.502, year: 2016

  9. Tungsten and molybdenum with oxide dispersion, production and properties

    International Nuclear Information System (INIS)

    Haerdtle, S.; Schmidberger, R.

    1989-01-01

    By the reaction spray process metal powders with dispersed metal oxides can be produced in one step. The systems investigated here are tungsten and molybdenum with 0,5% resp. 5% La 2 O 3 , Y 2 O 3 and ZrO 2 . The oxides with diameters below 0,5μm are finely dispersed within the metal powder particles. The sinterability of the powders depends on the oxide content. Maximum density at an oxide content of 0,5% is about 96% at a sintering temperature of 1600 0 C. The type of oxide influences the densification versus temperature but not the final density. 5 refs., 11 figs. (Author)

  10. Will Global Change Effect Primary Productivity in Coastal Ecosystems?

    Science.gov (United States)

    Rothschild, Lynn J.; Peterson, David L. (Technical Monitor)

    1997-01-01

    Algae are the base of coastal food webs because they provide the source of organic carbon for the remaining members of the community. Thus, the rate that they produce organic carbon to a large extent controls the productivity of the entire ecosystem. Factors that control algal productivity range from the physical (e.g., temperature, light), chemical (e.g., nutrient levels) to the biological (e.g., grazing). Currently, levels of atmospheric carbon dioxide surficial fluxes of ultraviolet radiation are rising. Both of these environmental variables can have a profound effect on algal productivity. Atmospheric carbon dioxide may increase surficial levels of dissolved inorganic carbon. Our laboratory and field studies of algal mats and phytoplankton cultures under ambient and elevated levels of pCO2 show that elevated levels of inorganic carbon can cause an increase in photosynthetic rates. In some cases, this increase will cause an increase in phytoplankton numbers. There may be an increase in the excretion of fixed carbon, which in turn may enhance bacterial productivity. Alternatively, in analogy with studies on the effect of elevated pCO2 on plants, the phytoplankton could change their carbon to nitrogen ratios, which will effect the feeding of the planktonic grazers. The seasonal depletion of stratospheric ozone has resulted in elevated fluxes of UVB radiation superimposed on the normal seasonal variation. Present surface UV fluxes have a significant impact on phytoplankton physiology, including the inhibition of the light and dark reactions of photosynthesis, inhibition of nitrogenase activity, inhibition of heterocyst formation, reduction in motility, increased synthesis of the UV-screening pigment scytonemin, and mutation. After reviewing these issues, recent work in our lab on measuring the effect of UV radiation on phytoplankton in the San Francisco Bay Estuary will be presented.

  11. LIFE CYCLE OF THE PHARMACEUTICAL PRODUCT AND PRIMARY STRATEGIC GOALS

    Directory of Open Access Journals (Sweden)

    Cristina\tCIOT

    2015-12-01

    Full Text Available In addition to innovation, production at high standards, market and marketing policy, pharmaceutical companies need strategies that could cope with apparent contradictions, convergences and divergences, centralisation and involution, at the global and local level, focus and liberty, domestic production and external supply, ownership and alliances, networks and hierarchies, science or market orientation, all these being part of the essence of a profitable and expanding pharmaceutical company. Specialists appreciate that the 20 century will remain in the collective memory for its technological achievements, including a better understanding of the atomic structure, „information explosion” encouraged by the progress of the computer technology, the news from space exploration. If one wants to evaluate its importance in terms of impact on people’s lives, the 20 century could be called THE DRUG AREA. Many experts agree that, at the end of this century, pharmaceutical products would have a higher importance for our lives due to the special progress in neurobiology, immunology, molecular biology, cellular differentiation, cell membrane and genetic studies. In the pharmaceutical industry, important funds are directed towards research and development, while few understand and appreciate the contribution brought by the pharmaceutical marketing system and by the professionals in this field. These ones make the drug accessible at the right time and place, in the required quantity, at a reasonable price and with all the information required.

  12. Method of manufacturing gadolinium oxide-incorporated nuclear fuel sintering products

    International Nuclear Information System (INIS)

    Komono, Akira; Seki, Makoto; Omori, Sadayuki.

    1987-01-01

    Purpose: To manufacture nuclear fuel sintering products excellent in burning property and mechanical property. Constitution: In the manufacturing step for nuclear fuel sintering products, specific metal oxides are added for promoting the growth of crystal grains in the sintering. Those metal oxides melted at a temperature lower than the sintering temperature of a mixture of nuclear fuel oxide powder and oxide power, or those metal oxides causing eutectic reaction are used as the metal oxide. Particularly, those compounds having oxygen atom - metal atom ratio (O/M) of not less than 2 are preferably used. As such metal oxides usable herein transition metal oxides, e.g., Nb 2 O 5 , TiO 2 , MoO 3 and WO 3 are preferred, with Nb 2 O 3 and TiO 2 being preferred particularly. (Seki, T.)

  13. Daya antibakteri penambahan Propolis pada zinc oxide eugenol dan zinc oxide terhadap kuman campur gigi molar sulung non vital (The antibacterial effect of propolis additional to zinc oxide eugenol and zinc oxide on polybacteria of necrotic primary molar

    Directory of Open Access Journals (Sweden)

    Yemy Ameliana

    2014-12-01

    Full Text Available Background: Materials commonly used for root canal filling of primary teeth is zinc oxide eugenol. Eugenol has some disadvantages that can irritate the periapical tissues, has the risk of disturbing the growth and development of permanent tooth buds, and has a narrow antibacterial spectrum. Studies showed that propolis at concentration of 20 % has antibacterial activity against Staphylococcus aureus. Purpose: The purpose of this study was to examine the antimicrobial activity of root canal pastes with the additional of propolis additional to zinc oxide eugenol (ZOEP and to zinc oxide (ZOP. Methods: Polybacteria cultures collected from root canals of necrotic primary molar from 5 children patients who received root canal treatment. The bacteria were grown in BHI Broth, and inoculated into Muller Hinton Agar media. The agar plates was divided into 3 areas, and one well was made at each area. The first well filled with ZOE as a control, second well filled with ZOEP and the third well filled with ZOP, then incubated for 24 hour at 370 C. Antimicrobial activity was determined by measuring the diameters of inhibition zones of polybacteria growth. The data were statistically analyzed by independent T-test. Results: The pasta mixture of zinc oxide propolis had the strongest antibacterial activity against polybacteria of necrotic primary molar, followed by zinc oxide eugenol propolis paste, and zinc oxide eugenol paste. There were significant differences of inhibition zones between ZOE, ZOEP and ZOP (p<0,05. Conclusion: The study suggested that the additional of propolis to zinc oxide paste could increase the antimicrobial effect against root canal polybacteria of necrotic primary molar.Latar belakang: Bahan yang sering digunakan untuk pengisian saluran akar gigi sulung adalah zinc oxide eugenol. Eugenol memiliki beberapa kekurangan yaitu dapat mengiritasi jaringan periapikal, beresiko mengganggu pertumbuhan dan perkembangan benih gigi permanen pengganti

  14. Characterization of interfacial reactions and oxide films on 316L stainless steel in various simulated PWR primary water environments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junjie; Xiao, Qian [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Mailbox 269, 149 Yanchang Road, Shanghai, 200072 (China); State Key Laboratory of Advanced Special Steels, Shanghai University, 149 Yanchang Road, Shanghai, 200072 (China); Lu, Zhanpeng, E-mail: zplu@t.shu.edu.cn [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Mailbox 269, 149 Yanchang Road, Shanghai, 200072 (China); State Key Laboratory of Advanced Special Steels, Shanghai University, 149 Yanchang Road, Shanghai, 200072 (China); Shanghai Key Laboratory of Advanced Ferrometallurgy, Shanghai University, 149 Yanchang Road, Shanghai, 200072 (China); Ru, Xiangkun; Peng, Hao; Xiong, Qi; Li, Hongjuan [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Mailbox 269, 149 Yanchang Road, Shanghai, 200072 (China)

    2017-06-15

    The effect of water chemistry on the electrochemical and oxidizing behaviors of 316L SS was investigated in hydrogenated, deaerated and oxygenated PWR primary water at 310 °C. Water chemistry significantly influenced the electrochemical impedance spectroscopy parameters. The highest charge-transfer resistance and oxide-film resistance occurred in oxygenated water. The highest electric double-layer capacitance and constant phase element of the oxide film were in hydrogenated water. The oxide films formed in deaerated and hydrogenated environments were similar in composition but different in morphology. An oxide film with spinel outer particles and a compact and Cr-rich inner layer was formed in both hydrogenated and deaerated water. Larger and more loosely distributed outer oxide particles were formed in deaerated water. In oxygenated water, an oxide film with hematite outer particles and a porous and Ni-rich inner layer was formed. The reaction kinetics parameters obtained by electrochemical impedance spectroscopy measurements and oxidation film properties relating to the steady or quasi-steady state conditions in the time-period of measurements could provide fundamental information for understanding stress corrosion cracking processes and controlling parameters. - Highlights: •Long-term EIS measurements of 316L SS in simulated PWR primary water. •Highest charge-transfer resistance and oxide film resistance in oxygenated water. •Highest electric double-layer capacitance and oxide film CPE in hydrogenated water. •Similar compositions, different shapes of oxides in deaerated/hydrogenated water. •Inner layer Cr-rich in hydrogenated/deaerated water, Ni-rich in oxygenated water.

  15. Characterization and assessment of dermal and inhalable nickel exposures in nickel production and primary user industries.

    Science.gov (United States)

    Hughson, G W; Galea, K S; Heim, K E

    2010-01-01

    The aim of this study was to measure the levels of nickel in the skin contaminant layer of workers involved in specific processes and tasks within the primary nickel production and primary nickel user industries. Dermal exposure samples were collected using moist wipes to recover surface contamination from defined areas of skin. These were analysed for soluble and insoluble nickel species. Personal samples of inhalable dust were also collected to determine the corresponding inhalable nickel exposures. The air samples were analysed for total inhalable dust and then for soluble, sulfidic, metallic, and oxidic nickel species. The workplace surveys were carried out in five different workplaces, including three nickel refineries, a stainless steel plant, and a powder metallurgy plant, all of which were located in Europe. Nickel refinery workers involved with electrolytic nickel recovery processes had soluble dermal nickel exposure of 0.34 microg cm(-2) [geometric mean (GM)] to the hands and forearms. The GM of soluble dermal nickel exposure for workers involved in packing nickel salts (nickel chloride hexahydrate, nickel sulphate hexahydrate, and nickel hydroxycarbonate) was 0.61 microg cm(-2). Refinery workers involved in packing nickel metal powders and end-user powder operatives in magnet production had the highest dermal exposure (GM = 2.59 microg cm(-2) soluble nickel). The hands, forearms, face, and neck of these workers all received greater dermal nickel exposure compared with the other jobs included in this study. The soluble nickel dermal exposures for stainless steel production workers were at or slightly above the limit of detection (0.02 microg cm(-2) soluble nickel). The highest inhalable nickel concentrations were observed for the workers involved in nickel powder packing (GM = 0.77 mg m(-3)), although the soluble component comprised only 2% of the total nickel content. The highest airborne soluble nickel exposures were associated with refineries using

  16. Primary Screening of 10 - Hydroxy - 2 - Decenoic Acid Productive Strains

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, eleven strains, which vere screened strictly from raw royal.jelly, soil and honeycomb etc. by means of dilution plate and spread plate methods, were cultured at 28°C for60 h with shaking. To determine whether they could yield 10-Hydroxy-2-decenoic acid during fermentation, gas chromatography and gas chromatography-mass spectrometry methods were used. The results showed that the strains BH002 and BH004. were both identified as Crvtococcaceae. where BH002 was primarily classified into Candida for possessing the abilities. The 10-HDA productivity of Candida BH002 and that of BH004 were 0.327% and 0.2648% respectively.

  17. Gaucher disease: plasmalogen levels in relation to primary lipid abnormalities and oxidative stress.

    Science.gov (United States)

    Moraitou, Marina; Dimitriou, Evangelia; Dekker, Nick; Monopolis, Ioannis; Aerts, Johannes; Michelakakis, Helen

    2014-01-01

    Plasmalogens represent a unique class of phospholipids. Reduced red blood cell plasmalogen levels in Gaucher disease patients were reported, correlating to total disease burden. The relation between plasmalogen abnormalities in Gaucher disease patients and primary glycosphingolipid abnormalities, malonyldialdehyde levels, an indicator of lipid peroxidation, and the total antioxidant status was further investigated. Significant reduction of C16:0 and C18:0 plasmalogens in red blood cells of Gaucher disease patients was confirmed. In parallel, a significant increase in the glucosylceramide/ceramide ratio in red blood cell membranes, as well as an average 200-fold increase in plasma glucosylsphingosine levels was observed. Red blood cell malonyldialdehyde levels were significantly increased in patients, whereas their total antioxidant status was significantly reduced. A negative correlation between plasmalogen species and glucosylceramide, ceramide, glucosylceramide/ceramide ratio, glucosylsphingosine and malonyldialdehyde, significant for the C16:0 species and all the above parameters with the exception of malonyldialdehyde levels, was found along with a positive non-significant correlation with the total antioxidant status. Our results indicate that increased lipid peroxidation and reduced total antioxidant status exist in Gaucher disease patients. They demonstrate a clear link between plasmalogen levels and the primary glycolipid abnormalities characterizing the disorder and an association with the increased oxidative stress observed in Gaucher disease patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Hepatoprotective Flavonoids in Opuntia ficus-indica Fruits by Reducing Oxidative Stress in Primary Rat Hepatocytes.

    Science.gov (United States)

    Kim, Jung Wha; Kim, Tae Bum; Kim, Hyun Woo; Park, Sang Wook; Kim, Hong Pyo; Sung, Sang Hyun

    2017-01-01

    Liver disorder was associated with alcohol consumption caused by hepatic cellular damages. Opuntia ficus-indica fruit extracts (OFIEs), which contain betalain pigments and polyphenols including flavonoids, have been introduced as reducing hangover symptoms and liver protective activity. To evaluate hepatoprotective activity of OFIEs and isolated compounds by high-speed countercurrent chromatography (HSCCC). The extract of O. ficus-indica fruits was fractionated into methylene chloride and n -butanol. The n -butanol fraction was isolated by HSCCC separation (methylene chloride-methanol- n -butanol-water, 5:4:3:5, v/v/v/v). The hepatoprotective activity of OFIEs and isolated compounds was evaluated on rat primary hepatocytes against ethanol-induced toxicity. Antioxidative parameters such as glutathione reductase and glutathione peroxidase (GSH-P x ) enzymes and the GSH content were measured. Two flavonoids, quercetin 3- O -methyl ester (1) and (+)-taxifolin, and two flavonoid glycosides, isorhamnetin 3- O -β- d -glucoside (3) and narcissin (4), were isolated from the n -butanol fraction by HSCCC separation. Among them, compound 2 significantly protected rat primary hepatocytes against ethanol exposure by preserving antioxidative properties of GR and GSH-P x . OFIEs and (+)-taxifolin were suggested to reduce hepatic damage by alcoholic oxidative stress. Hepatoprotective Flavonoids were isolated from Opuntia ficus-indica by high -speed countercurrent chromatography (HSCCC).

  19. Hydrogen Production via Steam Reforming of Ethyl Alcohol over Palladium/Indium Oxide Catalyst

    Directory of Open Access Journals (Sweden)

    Tetsuo Umegaki

    2009-01-01

    Full Text Available We report the synergetic effect between palladium and indium oxide on hydrogen production in the steam reforming reaction of ethyl alcohol. The palladium/indium oxide catalyst shows higher hydrogen production rate than indium oxide and palladium. Palladium/indium oxide affords ketonization of ethyl alcohol with negligible by-product carbon monoxide, while indium oxide mainly affords dehydration of ethyl alcohol, and palladium affords decomposition of ethyl alcohol with large amount of by-product carbon monoxide. The catalytic feature of palladium/indium oxide can be ascribed to the formation of palladium-indium intermetallic component during the reaction as confirmed by X-ray diffraction and X-ray photoelectron spectroscopic measurements.

  20. ARIES Oxide Production Program Assessment of Risk to Long-term Sustainable Production Rate

    Energy Technology Data Exchange (ETDEWEB)

    Whitworth, Julia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lloyd, Jane Alexandria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Majors, Harry W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-04

    This report describes an assessment of risks and the development of a risk watch list for the ARIES Oxide Production Program conducted in the Plutonium Facility at LANL. The watch list is an active list of potential risks and opportunities that the management team periodically considers to maximize the likelihood of program success. The initial assessments were made in FY 16. The initial watch list was reviewed in September 2016. The initial report was not issued. Revision 1 has been developed based on management review of the original watch list and includes changes that occurred during FY-16.

  1. Elastin aging and lipid oxidation products in human aorta

    Directory of Open Access Journals (Sweden)

    Kamelija Zarkovic

    2015-04-01

    Full Text Available Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA, (4-hydroxynonenal, malondialdehyde, acrolein, form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development.

  2. Interferon-γ and NF-κB mediate nitric oxide production by mesenchymal stromal cells

    International Nuclear Information System (INIS)

    Oh, I.; Ozaki, K.; Sato, K.; Meguro, A.; Tatara, R.; Hatanaka, K.; Nagai, T.; Muroi, K.; Ozawa, K.

    2007-01-01

    Mesenchymal stromal cells (MSCs) have been shown to have an immunosuppressive effect. Previously, we demonstrated that nitric oxide (NO) is one of the immunomodulatory mediators of MSCs. We herein show that primary mouse bone marrow MSCs and three cell lines that mimic MSCs suppress both differentiation and proliferation in Th1 condition, whereas the suppression in Th2 condition is mild. NO production is inversely correlated with T cell proliferation in Th1 and Th2 conditions. NO is highly induced in Th1 and minimally induced in Th2. Moreover, an inhibitor of NO synthase restores both proliferation and interferon-γ (IFN-γ) production in Th1 condition. Furthermore, an anti-IFN-γ antibody strongly inhibits NO production and an inhibitor of NF-κB reduces the level of induction of inducible NO synthase (iNOS) in MSCs. Taken together, our results suggest that NO plays a significant role in the modification of Th1 and Th2 differentiation by MSCs, and that both IFN-γ and NF-κB are critical for NO production by MSCs

  3. Nitric oxide production by Peromyscus yucatanicus (Rodentia infected with Leishmania (Leishmania mexicana

    Directory of Open Access Journals (Sweden)

    Elsy Nalleli Loría-Cervera

    2013-04-01

    Full Text Available Peromyscus yucatanicus (Rodentia: Cricetidae is a primary reservoir of Leishmania (Leishmania mexicana (Kinetoplastida: Trypanosomatidae. Nitric oxide (NO generally plays a crucial role in the containment and elimination of Leishmania. The aim of this study was to determine the amount of NO produced by P. yucatanicus infected with L. (L. mexicana. Subclinical and clinical infections were established in P. yucatanicus through inoculation with 1 x 10 2 and 2.5 x 10 6 promastigotes, respectively. Peritoneal macrophages were cultured alone or co-cultured with lymphocytes with or without soluble Leishmania antigen. The level of NO production was determined using the Griess reaction. The amount of NO produced was significantly higher (p ≤ 0.0001 in co-cultured macrophages and lymphocytes than in macrophages cultured alone. No differences in NO production were found between P. yucatanicus with subclinical L. (L. mexicana infections and animals with clinical infections. These results support the hypothesis that the immunological mechanisms of NO production in P. yucatanicus are similar to those described in mouse models of leishmaniasis and, despite NO production, P. yucatanicus is unable to clear the parasite infection.

  4. Primary production measurements at three reservoirs in the state of Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Jureidini, P.; Chinez, S.J.; Agudo, E.G.

    1983-01-01

    Primary production measurements were carried out at three reservoirs in the state of Sao Paulo, Barra Bonita, Paiva Castro and Ponte nova using the 14 C technique. Meanwhile, several physical and chemical parameters of these water were also evaluated, in order to find out the limnological conditions of these reservoirs. Primary production rates ranged from 7,6mg C/m 3 d at Ponte Nova, to 247,2mg C/m 3 d at Barra Bonita. There seems to be god correlation between water quality data and primary production measurements. Regarding the results, it may be stated that the Barra Bonita reservoir has reached the eutrophic level, while the other two exibit mesotrophic levels. As a way of testing the water quality data collected was used in Churchill and Nicholas model, issuing results in agreement with those of the primary production measurements. (Author) [pt

  5. HANPP Collection: Global Patterns in Human Appropriation of Net Primary Productivity (HANPP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Human Appropriation of Net Primary Productivity (HANPP) portion of the HANPP Collection represents a digital map of human appropriation of net...

  6. Safety assessment of smoke flavouring primary products by the European Food Safety Authority

    NARCIS (Netherlands)

    Theobald, A.; Arcella, D.; Carere, A.; Croera, C.; Engel, K.H.; Gott, D.; Gurtler, R.; Meier, D.; Pratt, I.; Rietjens, I.M.C.M.; Simon, R.; Walker, R.

    2012-01-01

    This paper summarises the safety assessments of eleven smoke flavouring primary products evaluated by the European Food Safety Authority (EFSA). Data on chemical composition, content of polyaromatic hydrocarbons and results of genotoxicity tests and subchronic toxicity studies are presented and

  7. NODC Standard Format Primary Productivity 1 (F029) Data (1958-1983) (NODC Accession 0014152)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains data from measurements of primary productivity. The data are collected to provide information on nutrient levels and nutrient flow in offshore...

  8. Recent Primary Production and Small Phytoplankton Contribution in the Yellow Sea during the Summer in 2016

    Science.gov (United States)

    Jang, Hyo Keun; Kang, Jae Jung; Lee, Jae Hyung; Kim, Myungjoon; Ahn, So Hyun; Jeong, Jin-Yong; Yun, Mi Sun; Han, In-Seong; Lee, Sang Heon

    2018-05-01

    The high nutrient concentration associated with the mixing dynamics of two warm and cold water masses supports high primary production in the Yellow Sea. Although various environmental changes have been reported, no recent information on small phytoplankton contribution to the total primary production as an important indicator for marine ecosystem changes is currently available in the Yellow Sea. The major objective of this study is to determine the small (values decades ago. The higher contributions of small phytoplankton to the total chlorophyll a concentration and primary production might be caused by P-limited conditions and this resulted in lower chlorophyll a concentration and total primary production in this study compared to previous studies.

  9. Primary productivity in the Karwar Bay, Karnataka, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, U.G.; Naik, R.K.; Nayak, V.N.

    The measurement of primary production is of great importance because of its significance to the problems of aquatic ecology and fishery management. The interaction of light intensity, temperature and nutrient levels determines the photosynthetic...

  10. Remote sensing of oceanic primary production: Computations using a spectral model

    Digital Repository Service at National Institute of Oceanography (India)

    Sathyendranath, S.; Platt, T.; Caverhill, C.M.; Warnock, R.E.; Lewis, M.R.

    A spectral model of underwater irradiance is coupled with a spectral version of the photosynthesis-light relationship to compute oceanic primary production. The results are shown to be significantly different from those obtained using...

  11. Phytoplankton pigments and primary production around the oil fields off Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    JiyalalRam, M.J.; Ramaiah, Neelam; Mehta, P.; Krishnakumari, L.; Nair, V.R.

    Studies on phytoplankton pigments, primary productivity and particulate organic carbon were made at 21 locations off Bombay (Maharashtra, India) and adjacent waters during the 48th cruise of @iORV Sagar Kanya@@ in December 1988 to January 1989...

  12. Ocean primary production and available light: Further algorithms for remote sensing

    Digital Repository Service at National Institute of Oceanography (India)

    Platt, T.; Sathyendranath, S.; Caverhill, C.M.; Lewis, M.R.

    (1986, Deep-Sea Research, 33, 149-163) Further empirical evidence is presented to show the stability of the relationship between surface light and biomass-normalized primary production of the ocean water column A theoretical explanation is given...

  13. Primary productivity of marine macrophytes in the coral reef lagoon of the Kadmat Island, Lakshadweep

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.; Shaikh, N.

    n situ primary productivity measurements were carried out with different macrophyte species (belonging to four groups) dominating the benthic communities in the coral reef lagoon of the Kadmat Island of the Lakshadweep Archipelago...

  14. Analysis of microbial populations, denitrification, and nitrous oxide production in riparian buffers

    Science.gov (United States)

    Riparian buffers are used extensively to protect water bodies from nonpoint source nitrogen pollution. However there is relatively little information on the impact of these buffers on production of nitrous oxide (N2O). In this study, we assessed nitrous oxide production in riparian buffers of the so...

  15. Methods to assess secondary volatile lipid oxidation products in complex food matrices

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Yesiltas, Betül

    A range of different methods are available to determine secondary volatile lipid oxidation products. These methods include e.g. spectrophotometric determination of anisidine values and TBARS as well as GC based methods for determination of specific volatile oxidation products such as pentanal...... headspace methods on the same food matrices will be presented....

  16. STIMULATION OF OXIDANT PRODUCTION IN ALVEOLAR MACROPHAGES BY POLLUTANT AND LATEX PARTICLES

    Science.gov (United States)

    Air pollutant dusts as well as chemically defined particles were examined for their activating effect on oxidant production (O2- and H2O2) in guinea pig alveolar macrophages (AM). Oxidant production was measured as chemiluminescence of albumin-bound luminol. All particles examine...

  17. NOx from cement production - reduction by primary measures

    DEFF Research Database (Denmark)

    Jensen, Lars Skaarup

    1999-01-01

    cement production processes cement is typically produced by thermally treating a mixture of limestone and clay minerals in kiln systems consisting of a rotary kiln and a calciner. Clinker burning at a temperature of about 1450 °C takes place in the internally fired rotary kiln and calcination, which...... rotary kilns, while NOx formation from fuel-N and reduction of NOx take place in calciners. NOx formation in the rotary kiln is mainly governed by the necessary clinker burning temperature and is not very amenable to control, while net NOx formation in calciners depends strongly on calciner design......, calciner operation, fuel properties and on the NOx level from the rotary kiln. The low-NOx calciner types presently marketed are based on combinations of reburning, air staging and temperature control and seem equivalent in their ability to restrict NOx formation. If fuels with a significant volatile...

  18. [Effects of metal-catalyzed oxidation on the formation of advanced oxidation protein products].

    Science.gov (United States)

    Li, Li; Peng, Ai; Zhu, Kai-Yuan; Yu, Hong; Ll, Xin-Hua; Li, Chang-Bin

    2008-03-11

    To explore the relationship between metal-catalyzed oxidation (MCO) and the formation of advanced oxidation protein products (AOPPs). Specimens of human serum albumin (HSA) and pooled plasma were collected from 3 healthy volunteers and 4 uremia patients were divided into 3 groups: Group A incubated with copper sulfate solution of the concentrations of 0, 0.2, or 0.5 mmol/L, Group B, incubated with hydrogen peroxide 2 mmol/L, and Group C, incubated with copper sulfate 0.2 or 0.5 mmol/L plus hydrogen peroxide 2 mmol/L. 30 min and 24 h later the AOPP level was determined by ultraviolet visible spectrophotometry. High-performance liquid chromatography (HPLC) was used to observe the fragmentation effect on plasma proteins. Ninhydrin method was used to examine the protein fragments. The scavenging capacity of hydroxyl radical by macromolecules was measured so as to estimate the extent of damage for proteins induced by MCO. (1) The AOPP level of the HSA and plasma specimens of the uremia patients increased along with the increase of cupric ion concentration in a dose-dependent manner, especially in the presence of hydrogen peroxide (P < 0.05). (2) Aggregation of proteins was almost negligible in all groups, however, HPLC showed that cupric ion with or without hydrogen peroxide increased the fragments in the HAS specimens (with a relative molecular mass of 5000) and uremia patients' plasma proteins (with the molecular mass 7000). (3) The plasma AOPP level of the healthy volunteers was 68.2 micromol/L +/- 2.4 micromol/L, significantly lower than that of the uremia patients (158.5 micromol/L +/- 8.2 micromol/L). (4) The scavenging ability to clear hydroxyl radical by plasma proteins of the healthy volunteers was 1.38 -9.03 times as higher than that of the uremia patients. MCO contributes to the formation of AOPPs mainly through its fragmentation effect to proteins.

  19. Methylmercury bioaccumulation in stream food webs declines with increasing primary production

    Science.gov (United States)

    Walters, David; D.F. Raikow,; C.R. Hammerschmidt,; M.G. Mehling,; A. Kovach,; J.T. Oris,

    2015-01-01

    Opposing hypotheses posit that increasing primary productivity should result in either greater or lesser contaminant accumulation in stream food webs. We conducted an experiment to evaluate primary productivity effects on MeHg accumulation in stream consumers. We varied light for 16 artificial streams creating a productivity gradient (oxygen production =0.048–0.71 mg O2 L–1 d–1) among streams. Two-level food webs were established consisting of phytoplankton/filter feeding clam, periphyton/grazing snail, and leaves/shredding amphipod (Hyalella azteca). Phytoplankton and periphyton biomass, along with MeHg removal from the water column, increased significantly with productivity, but MeHg concentrations in these primary producers declined. Methylmercury concentrations in clams and snails also declined with productivity, and consumer concentrations were strongly correlated with MeHg concentrations in primary producers. Heterotroph biomass on leaves, MeHg in leaves, and MeHg in Hyalella were unrelated to stream productivity. Our results support the hypothesis that contaminant bioaccumulation declines with stream primary production via the mechanism of bloom dilution (MeHg burden per cell decreases in algal blooms), extending patterns of contaminant accumulation documented in lakes to lotic systems.

  20. Parameterization of surface irradiance and primary production in Århus Bay, SW Kattegat, Baltic Sea

    DEFF Research Database (Denmark)

    Lund-Hansen, Lars Chresten; Sørensen, Helene Munk

    2009-01-01

    . The study is based on a one year long time-series of PAR, CTD-casts (n = 45), and primary production measurements (n = 24) from Århus Bay (56°09′ N; 10°20′ E), south west Kattegat. Results showed a high and positive correlation between observed and calculated primary production in the bay, as based...

  1. Low nitrous oxide production in intermittent-feed high performance nitritating reactors

    DEFF Research Database (Denmark)

    Su, Qingxian; Jensen, Malene M.; Smets, Barth F.

    Nitrous oxide (N2O) production from autotrophic nitrogen removal processes, especially nitritating systems, is of growing concern. N2O dynamics were characterized and N2O production factors were quantified in two lab-scale intermittent-feed nitritating SBRs. 93 ± 14% of the oxidized ammonium...... was converted to nitrite, with the average total net N2O production of 2.1 ± 0.7% of the ammonium oxidized. Operation with intermittent feeding appears an effective optimization approach to mitigate N2O emissions from nitritating systems. Net N2O production rates transiently increased with a rise in pH after...

  2. Detection of HOCl-mediated protein oxidation products in the extracellular matrix of human atherosclerotic plaques

    DEFF Research Database (Denmark)

    Woods, Alan A; Linton, Stuart M; Davies, Michael Jonathan

    2003-01-01

    Oxidation is believed to play a role in atherosclerosis. Oxidized lipids, sterols and proteins have been detected in early, intermediate and advanced human lesions at elevated levels. The spectrum of oxidized side-chain products detected on proteins from homogenates of advanced human lesions has...... been interpreted in terms of the occurrence of two oxidative mechanisms, one involving oxygen-derived radicals catalysed by trace transition metal ions, and a second involving chlorinating species (HOCl or Cl2), generated by the haem enzyme myeloperoxidase (MPO). As MPO is released extracellularly...... for 83-96% of the total oxidized protein side-chain products detected in these plaques. Oxidation of matrix components extracted from healthy artery tissue, and model proteins, with reagent HOCl is shown to give rise to a similar pattern of products to those detected in advanced human lesions...

  3. Elastin aging and lipid oxidation products in human aorta.

    Science.gov (United States)

    Zarkovic, Kamelija; Larroque-Cardoso, Pauline; Pucelle, Mélanie; Salvayre, Robert; Waeg, Georg; Nègre-Salvayre, Anne; Zarkovic, Neven

    2015-01-01

    Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM) components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs) are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA), (4-hydroxynonenal, malondialdehyde, acrolein), form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Measurements of nitrous oxide emissions from vegetable production in China

    Science.gov (United States)

    Xiong, Zhengqin; Xie, Yingxin; Xing, Guangxi; Zhu, Zhaoliang; Butenhoff, Chris

    Nitrous oxide (N 2O) emissions resulting from Chinese vegetable production were measured. A site in suburban Nanjing (East coast; Jiangsu Province) was monitored from November 2001 to January 2003, in which five consecutive vegetable crops were sown. The crops consisted of radish, baby bok choy, lettuce, second planting of baby bok choy, and finally celery. Results suggested that N 2O emission events occur in pulses. The average N 2O-N flux for all five crops was 148±9 μg N m -2 h -1 and the average emission rate was 12±0.7 kg N ha -1. The average seasonal emission fluxes ranged from 37 μg N m -2 h -1 in the radish plot to 300 μg N m -2 h -1 in the celery plot. The celery field produced the greatest cumulative emission of 5.8 kg N ha -1 while the baby bok choy field had the lowest rate of 0.96-1.0 kg N ha -1. In total, 0.73% of applied fertilizer N was emitted as N 2O-N as a whole. The lettuce field had the largest emission factor of 2.2%. Results indicate that emissions from vegetable field are a potential source of national N 2O inventory. Temporal variation is much greater than spatial variation and the corresponding CV averaged 115% and 22%, respectively. Under the same total sampling quantity, increasing sampling frequency is more important than increasing spatial replicates.

  5. Hot-spots of primary productivity: An Alternative interpretation to Conventional upwelling models

    Science.gov (United States)

    van Ruth, Paul D.; Ganf, George G.; Ward, Tim M.

    2010-12-01

    The eastern Great Australian Bight (EGAB) forms part of the Southern and Indian Oceans and is an area of high ecological and economic importance. Although it supports a commercial fishery, quantitative estimates of the primary productivity underlying this industry are open to debate. Estimates range from 500 mg C m -2 day -1. Part of this variation may be due to the unique upwelling circulation of shelf waters in summer/autumn (November-April), which shares some similarities with highly productive eastern boundary current upwelling systems, but differs due to the influence of a northern boundary current, the Flinders current, and a wide continental shelf. This study examines spatial variations in primary productivity in the EGAB during the upwelling seasons of 2005 and 2006. Daily integral productivity calculated using the vertically generalised production model (VGPM) showed a high degree of spatial variation. Productivity was low (modelled with the VGPM, which uses surface measures of phytoplankton biomass to calculate productivity. Macro-nutrient concentrations could not be used to explain the difference in the low and high productivities (silica > 1 μmol L -1, nitrate/nitrite > 0.4 μmol L -1, phosphate > 0.1 μmol L -1). Mixing patterns or micro-nutrient concentrations are possible explanations for spatial variations in primary productivity in the EGAB. On a global scale, daily rates of primary productivity of the EGAB lie between the highly productive eastern boundary current upwelling systems, and less productive coastal regions of western and south eastern Australia, and the oligotrophic ocean. However, daily productivity rates in the upwelling hotspots of the EGAB rival productivities in Benguela and Humboldt currents.

  6. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section 50.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL...

  7. Amorphous semiconducting and conducting transparent metal oxide thin films and production thereof

    Science.gov (United States)

    Perkins, John; Van Hest, Marinus Franciscus Antonius Maria; Ginley, David; Taylor, Matthew; Neuman, George A.; Luten, Henry A.; Forgette, Jeffrey A.; Anderson, John S.

    2010-07-13

    Metal oxide thin films and production thereof are disclosed. An exemplary method of producing a metal oxide thin film may comprise introducing at least two metallic elements and oxygen into a process chamber to form a metal oxide. The method may also comprise depositing the metal oxide on a substrate in the process chamber. The method may also comprise simultaneously controlling a ratio of the at least two metallic elements and a stoichiometry of the oxygen during deposition. Exemplary amorphous metal oxide thin films produced according to the methods herein may exhibit highly transparent properties, highly conductive properties, and/or other opto-electronic properties.

  8. Kinetics, Mechanism, and Secondary Organic Aerosol Yield of Aqueous Phase Photo-oxidation of α-Pinene Oxidation Products.

    Science.gov (United States)

    Aljawhary, Dana; Zhao, Ran; Lee, Alex K Y; Wang, Chen; Abbatt, Jonathan P D

    2016-03-10

    Formation of secondary organic aerosol (SOA) involves atmospheric oxidation of volatile organic compounds (VOCs), the majority of which are emitted from biogenic sources. Oxidation can occur not only in the gas-phase but also in atmospheric aqueous phases such as cloudwater and aerosol liquid water. This study explores for the first time the aqueous-phase OH oxidation chemistry of oxidation products of α-pinene, a major biogenic VOC species emitted to the atmosphere. The kinetics, reaction mechanisms, and formation of SOA compounds in the aqueous phase of two model compounds, cis-pinonic acid (PIN) and tricarballylic acid (TCA), were investigated in the laboratory; TCA was used as a surrogate for 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), a known α-pinene oxidation product. Aerosol time-of-flight chemical ionization mass spectrometry (Aerosol-ToF-CIMS) was used to follow the kinetics and reaction mechanisms at the molecular level. Room-temperature second-order rate constants of PIN and TCA were determined to be 3.3 (± 0.5) × 10(9) and 3.1 (± 0.2) × 10(8) M(-1) s(-1), respectively, from which were estimated their condensed-phase atmospheric lifetimes. Aerosol-ToF-CIMS detected a large number of products leading to detailed reaction mechanisms for PIN and MBTCA. By monitoring the particle size distribution after drying, the amount of SOA material remaining in the particle phase was determined. An aqueous SOA yield of 40 to 60% was determined for PIN OH oxidation. Although recent laboratory studies have focused primarily on aqueous-phase processing of isoprene-related compounds, we demonstrate that aqueous formation of SOA materials also occurs from monoterpene oxidation products, thus representing an additional source of biogenically driven aerosol formation.

  9. Estimation of livestock appropriation of net primary productivity in Texas Drylands

    Science.gov (United States)

    Robert Washington-Allen; Jody Fitzgerald; Stephanie Grounds; Faisar Jihadi; John Kretzschmar; Kathryn Ramirez; John Mitchell

    2009-01-01

    The ecological state of US Drylands is unknown. This research is developing procedures to determine the impact of the ecological footprint of grazing livestock on the productive capacity of US Drylands. A pilot geodatabase was developed for the state of Texas that includes 2002 data for county boundaries, net primary productivity (NPP) derived from the Moderate...

  10. Patterns of new versus recycled primary production in the terrestrial biosphere

    Science.gov (United States)

    Nitrogen (N) and phosphorus (P) availability regulate plant productivity throughout the terrestrial biosphere, influencing the patterns and magnitude of net primary production (NPP) by land plants both now and into the future. These nutrients enter ecosystems via geologic and atmospheric pathways, a...

  11. PRIMARY PRODUCTION OF SEAGRASS BEDS IN SOUTH SULAWESI (INDONESIA) - A COMPARISON OF HABITATS, METHODS AND SPECIES

    NARCIS (Netherlands)

    ERFTEMEIJER, PLA; OSINGA, R; MARS, AE

    Primary production of tropical seagrass meadows was studied between April and August 1990 in South Sulawesi, Indonesia. Oxygen evolution studies in enclosures over seagrass vegetation revealed gross community production values between 900 and 4400 mg C m-2 day-1. Assumed community respiration ranged

  12. Primary gas- and particle-phase emissions and secondary organic aerosol production from gasoline and diesel off-road engines.

    Science.gov (United States)

    Gordon, Timothy D; Tkacik, Daniel S; Presto, Albert A; Zhang, Mang; Jathar, Shantanu H; Nguyen, Ngoc T; Massetti, John; Truong, Tin; Cicero-Fernandez, Pablo; Maddox, Christine; Rieger, Paul; Chattopadhyay, Sulekha; Maldonado, Hector; Maricq, M Matti; Robinson, Allen L

    2013-12-17

    Dilution and smog chamber experiments were performed to characterize the primary emissions and secondary organic aerosol (SOA) formation from gasoline and diesel small off-road engines (SOREs). These engines are high emitters of primary gas- and particle-phase pollutants relative to their fuel consumption. Two- and 4-stroke gasoline SOREs emit much more (up to 3 orders of magnitude more) nonmethane organic gases (NMOGs), primary PM and organic carbon than newer on-road gasoline vehicles (per kg of fuel burned). The primary emissions from a diesel transportation refrigeration unit were similar to those of older, uncontrolled diesel engines used in on-road vehicles (e.g., premodel year 2007 heavy-duty diesel trucks). Two-strokes emitted the largest fractional (and absolute) amount of SOA precursors compared to diesel and 4-stroke gasoline SOREs; however, 35-80% of the NMOG emissions from the engines could not be speciated using traditional gas chromatography or high-performance liquid chromatography. After 3 h of photo-oxidation in a smog chamber, dilute emissions from both 2- and 4-stroke gasoline SOREs produced large amounts of semivolatile SOA. The effective SOA yield (defined as the ratio of SOA mass to estimated mass of reacted precursors) was 2-4% for 2- and 4-stroke SOREs, which is comparable to yields from dilute exhaust from older passenger cars and unburned gasoline. This suggests that much of the SOA production was due to unburned fuel and/or lubrication oil. The total PM contribution of different mobile source categories to the ambient PM burden was calculated by combining primary emission, SOA production and fuel consumption data. Relative to their fuel consumption, SOREs are disproportionately high total PM sources; however, the vastly greater fuel consumption of on-road vehicles renders them (on-road vehicles) the dominant mobile source of ambient PM in the Los Angeles area.

  13. In situ Raman Spectroscopy of Oxide Films on Zirconium Alloy in Simulated PWR Primary Water Condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Ho; Choi, Kyoung Joon; Yoo, Seung Chang; Kim, Ji Hyun [UNIST, Ulsan (Korea, Republic of)

    2016-05-15

    The two layered oxide structure is formed in pre-transition oxide for the zirconium alloy in high temperature water environment. It is known that the corrosion rate is related to the volume fraction of zirconium oxide and the pores in the oxides; therefore, the aim of this paper is to investigate the oxidation behavior in the pretransition zirconium oxide in high-temperature water chemistry. In this work, Raman spectroscopy was used for in situ investigations for characterizing the phase of zirconium oxide. In situ Raman spectroscopy is a well-suited technique for investigating in detail the characteristics of oxide films in a high-temperature corrosion environment. In previous studies, an in situ Raman system was developed for investigating the oxides on nickel-based alloys and low alloy steels in high-temperature water environment. Also, the early stage oxidation behavior of zirconium alloy with different dissolved hydrogen concentration environments in high temperature water was treated in the authors' previous study. In this study, a specific zirconium alloy was oxidized and investigated with in situ Raman spectroscopy for 100 d oxidation, which is close to the first transition time of the zirconium alloy oxidation. The ex situ investigation methods such as transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) were used to further characterize the zirconium oxide structure. As oxidation time increased, the Raman peaks of tetragonal zirconium oxide were merged or became weaker. However, the monoclinic zirconium oxide peaks became distinct. The tetragonal zirconium oxide was just found near the O/M interface and this could explain the Raman spectra difference between the 30 d result and others.

  14. Microbial production of nitrous oxide and nitric oxide in boreal peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Regina, K.

    1998-12-31

    Soils are an important source of nitrous oxide (N{sub 2}O) and nitric oxide (NO). N{sub 2}O is a greenhouse gas participating in both warming of the climate and the destruction of ozone, and NO is active in tropospheric chemistry. The fluxes and formation mechanisms of these gases in boreal Finnish peatlands were studied by both laboratory and field techniques. Special attention was paid to factors regulating their production, e.g. height of the water table, pH, temperature, nutrient level and nitrification activity. Both N{sub 2}O and NO fluxes were detected in the peatlands, some of which were sources of these trace gases and some sinks. The flux rates of N{sub 2}O ranged from negative values to several milligrammes per square metre per day. Natural peatlands were the lowest sources of N{sub 2}O, often showing negative fluxes, whereas sites drained for forestry some decades ago had markedly higher fluxes. A site drained for agriculture (grassland) was the highest source found. NO fluxes were observed on the two drained sites studied, a forested fen and the same field of grass, but not on a natural fen with a high water table. NO fluxes amounted to 16-30 % of the N{sub 2}O flux rates. The importance of the water table in regulating N{sub 2}0 fluxes was demonstrated in field and laboratory studies. It was shown in the laboratory that even a short lowering of the water table, for 14 weeks at 20 deg C, induced N{sub 2}0 fluxes from the fens that normally acted as sinks or only low sources. Raising the water table in peat monoliths from drained sites reduced the flux of N{sub 2}O. Nutrient-rich peatlands had much higher capacities for N{sub 2}O and NO production than poorer ones. The addition of KNO{sub 3}, NH{sub 4}Cl or urea to minerotrophic peat further increased the fluxes of N{sub 2}O and NO, and also nitrogen mineralisation. There was a clear connection between the fluxes of N{sub 2}0 and NO and nitrification activity measured as the numbers of nitrite

  15. Microbial production of nitrous oxide and nitric oxide in boreal peatlands

    International Nuclear Information System (INIS)

    Regina, K.

    1998-01-01

    Soils are an important source of nitrous oxide (N 2 O) and nitric oxide (NO). N 2 O is a greenhouse gas participating in both warming of the climate and the destruction of ozone, and NO is active in tropospheric chemistry. The fluxes and formation mechanisms of these gases in boreal Finnish peatlands were studied by both laboratory and field techniques. Special attention was paid to factors regulating their production, e.g. height of the water table, pH, temperature, nutrient level and nitrification activity. Both N 2 O and NO fluxes were detected in the peatlands, some of which were sources of these trace gases and some sinks. The flux rates of N 2 O ranged from negative values to several milligrammes per square metre per day. Natural peatlands were the lowest sources of N 2 O, often showing negative fluxes, whereas sites drained for forestry some decades ago had markedly higher fluxes. A site drained for agriculture (grassland) was the highest source found. NO fluxes were observed on the two drained sites studied, a forested fen and the same field of grass, but not on a natural fen with a high water table. NO fluxes amounted to 16-30 % of the N 2 O flux rates. The importance of the water table in regulating N 2 0 fluxes was demonstrated in field and laboratory studies. It was shown in the laboratory that even a short lowering of the water table, for 14 weeks at 20 deg C, induced N 2 0 fluxes from the fens that normally acted as sinks or only low sources. Raising the water table in peat monoliths from drained sites reduced the flux of N 2 O. Nutrient-rich peatlands had much higher capacities for N 2 O and NO production than poorer ones. The addition of KNO 3 , NH 4 Cl or urea to minerotrophic peat further increased the fluxes of N 2 O and NO, and also nitrogen mineralisation. There was a clear connection between the fluxes of N 2 0 and NO and nitrification activity measured as the numbers of nitrite-oxidising bacteria, nitrification potential or in situ net

  16. Microbial production of nitrous oxide and nitric oxide in boreal peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Regina, K

    1999-12-31

    Soils are an important source of nitrous oxide (N{sub 2}O) and nitric oxide (NO). N{sub 2}O is a greenhouse gas participating in both warming of the climate and the destruction of ozone, and NO is active in tropospheric chemistry. The fluxes and formation mechanisms of these gases in boreal Finnish peatlands were studied by both laboratory and field techniques. Special attention was paid to factors regulating their production, e.g. height of the water table, pH, temperature, nutrient level and nitrification activity. Both N{sub 2}O and NO fluxes were detected in the peatlands, some of which were sources of these trace gases and some sinks. The flux rates of N{sub 2}O ranged from negative values to several milligrammes per square metre per day. Natural peatlands were the lowest sources of N{sub 2}O, often showing negative fluxes, whereas sites drained for forestry some decades ago had markedly higher fluxes. A site drained for agriculture (grassland) was the highest source found. NO fluxes were observed on the two drained sites studied, a forested fen and the same field of grass, but not on a natural fen with a high water table. NO fluxes amounted to 16-30 % of the N{sub 2}O flux rates. The importance of the water table in regulating N{sub 2}0 fluxes was demonstrated in field and laboratory studies. It was shown in the laboratory that even a short lowering of the water table, for 14 weeks at 20 deg C, induced N{sub 2}0 fluxes from the fens that normally acted as sinks or only low sources. Raising the water table in peat monoliths from drained sites reduced the flux of N{sub 2}O. Nutrient-rich peatlands had much higher capacities for N{sub 2}O and NO production than poorer ones. The addition of KNO{sub 3}, NH{sub 4}Cl or urea to minerotrophic peat further increased the fluxes of N{sub 2}O and NO, and also nitrogen mineralisation. There was a clear connection between the fluxes of N{sub 2}0 and NO and nitrification activity measured as the numbers of nitrite

  17. Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium

    Directory of Open Access Journals (Sweden)

    C. H. Frame

    2010-09-01

    Full Text Available Nitrous oxide (N2O is a trace gas that contributes to the greenhouse effect and stratospheric ozone depletion. The N2O yield from nitrification (moles N2O-N produced per mole ammonium-N consumed has been used to estimate marine N2O production rates from measured nitrification rates and global estimates of oceanic export production. However, the N2O yield from nitrification is not constant. Previous culture-based measurements indicate that N2O yield increases as oxygen (O2 concentration decreases and as nitrite (NO2 concentration increases. Here, we have measured yields of N2O from cultures of the marine β-proteobacterium Nitrosomonas marina C-113a as they grew on low-ammonium (50 μM media. These yields, which were typically between 4 × 10−4 and 7 × 10−4 for cultures with cell densities between 2 × 102 and 2.1 × 104 cells ml−1, were lower than previous reports for ammonia-oxidizing bacteria. The observed impact of O2 concentration on yield was also smaller than previously reported under all conditions except at high starting cell densities (1.5 × 106 cells ml−1, where 160-fold higher yields were observed at 0.5% O2 (5.1 μM dissolved O2 compared with 20% O2 (203 μM dissolved O2. At lower cell densities (2 × 102 and 2.1 × 104 cells ml−1, cultures grown under 0.5% O2 had yields that were only 1.25- to 1.73-fold higher than cultures grown under 20% O2. Thus, previously reported many-fold increases in N2O yield with dropping O2 could be reproduced only at cell densities that far exceeded those of ammonia oxidizers in the ocean. The presence of excess NO2 (up to 1 mM in the growth

  18. Simulation of nitrous oxide and nitric oxide emissions from tropical primary forests in the Costa Rican Atlantic Zone

    Science.gov (United States)

    Shuguanga Liu; William A. Reiners; Michael Keller; Davis S. Schimel

    2000-01-01

    Nitrous oxide (N2O) and nitric oxide (NO) are important atmospheric trace gases participating in the regulation of global climate and environment. Predictive models on the emissions of N2O and NO emissions from soil into the atmosphere are required. We modified the CENTURY model (Soil Sci. Soc. Am. J., 51 (1987) 1173) to simulate the emissions of N2O and NO from...

  19. Changes in water chemistry and primary productivity of a reactor cooling reservoir (Par Pond)

    International Nuclear Information System (INIS)

    Tilly, L.J.

    1975-01-01

    Water chemistry and primary productivity of a reactor cooling reservoir have been studied for 8 years. Initially the primary productivity increased sixfold, and the dissolved solids doubled. The dissolved-solids increase appears to have been caused by additions of makeup water from the Savannah River and by evaporative concentration during the cooling process. As the dissolved-solids concentrations and the conductivity of makeup water leveled off, the primary productivity stabilized. Major cation and anion concentrations generally followed total dissolved solids through the increase and plateau; however, silica concentrations declined steadily during the initial period of increased plankton productivity. Standing crops of net seston and centrifuge seston did not increase during this initial period. The collective data show the effects of thermal input to a cooling reservoir, illustrate the need for limnological studies before reactor siting, and suggest the possibility of using makeup-water additions to power reactor cooling basins as a reservoir management tool

  20. Recruitment and condition of juvenile sandeel on the Faroe shelf in relation to primary production

    DEFF Research Database (Denmark)

    Eliasen, Kirstin; Reinert, Jákup; Gaard, Eilif

    The food of early-life sandeel is dominated by zooplankton, which again depends on primary production. On the Faroe Shelf, measurements of accumulated new primary production and chlorophyll a during spring and summer have been carried out since 1990 and 1997, respectively. Large inter...... availability. We compare the time series from the sandeel 0-group surveys with data on phytoplankton production and biomass. The results confirm that survival and condition of the early-life stages of sandeel on the Faroe Shelf is dependent on the magnitude of the primary production. Although the sandeel......-annual variations in the onset of the spring bloom and its intensity have been observed. Since 1974 juvenile sandeels have been sampled annually on the Faroe shelf. These results also show large variations – both in number and in average length. Here, we investigate the variations in recruitment in relation to food...

  1. Petrology of chromite in ureilites: Deconvolution of primary oxidation states and secondary reduction processes

    Science.gov (United States)

    Goodrich, Cyrena Anne; Harlow, George E.; Van Orman, James A.; Sutton, Stephen R.; Jercinovic, Michael J.; Mikouchi, Takashi

    2014-06-01

    Ureilites are ultramafic achondrites thought to be residues of partial melting on a carbon-rich asteroid. They show a trend of FeO-variation (olivine Fo from ∼74 to 95) that suggests variation in oxidation state. Whether this variation was established during high-temperature igneous processing on the ureilite parent body (UPB), or preserved from nebular precursors, is a subject of debate. The behavior of chromium in ureilites offers a way to assess redox conditions during their formation and address this issue, independent of Fo. We conducted a petrographic and mineral compositional study of occurrences of chromite (Cr-rich spinel) in ureilites, aimed at determining the origin of the chromite in each occurrence and using primary occurrences to constrain models of ureilite petrogenesis. Chromite was studied in LEW 88774 (Fo 74.2), NWA 766 (Fo 76.7), NWA 3109 (Fo 76.3), HaH 064 (Fo 77.5), LAP 03587 (Fo 74.9), CMS 04048 (Fo 76.4), LAP 02382 (Fo 78.6) and EET 96328 (Fo 85.2). Chromite occurs in LEW 88774 (∼5 vol.%), NWA 766 (event involved initial elevation of T (to 1300-1400 °C), followed by rapid decompression and drop in T (to exclusively in low-Fo samples supports the interpretation that the ureilite FeO-variation was established during igneous processing on the UPB.

  2. Carrot Loss during Primary Production : Field Waste and Pack House Waste.

    OpenAIRE

    Bond, Rebekka

    2016-01-01

    Background: it has been suggested that roughly one-third of all food produced for human consumption is lost or wasted globally. The reduction of loss and waste is seen as an important societal issue with considerable ethical, ecological and economic implications. Fruit and vegetables have the highest wastage rates of any food products; (45 %). And a big part of this waste occurs during production, but empirical data on loss during primary production is limited. Carrots are an important hortic...

  3. Effects of garlic extract on color, lipid oxidation and oxidative breakdown products in raw ground beef during refrigerated storage

    Directory of Open Access Journals (Sweden)

    XINZHUANG ZHANG

    2016-03-01

    Full Text Available The study aims to investigate the effects of garlic extracts on color, lipid oxidation, and oxidative breakdown products in raw ground beef during refrigerated storage. The two treatments were:control group (C, with no addition and experiment group (D, 50 mg garlic extracts added to 100 g beef. Adding garlic extracts significant increased a* value (PA ≤ 0.05, and significant decreased TBARS and PV values (PA ≤ 0.05. The pH and –SH value of D group had a decreasing tendency (PA=0.0522 and an increasing tendency (PA=0.0636 respectively compared to C group. Garlic extracts protected phospholipids, fatty acids and polypeptides from oxidation. The results indicatethat garlic extracts have the antioxidant activity, helping maintain the meat color, inhibiting lipid oxidation and protein degradation of raw ground beef during refrigerated storage.

  4. Temperature dependence of CO2-enhanced primary production in the European Arctic Ocean

    KAUST Repository

    Holding, J. M.

    2015-08-31

    The Arctic Ocean is warming at two to three times the global rate1 and is perceived to be a bellwether for ocean acidification2, 3. Increased CO2 concentrations are expected to have a fertilization effect on marine autotrophs4, and higher temperatures should lead to increased rates of planktonic primary production5. Yet, simultaneous assessment of warming and increased CO2 on primary production in the Arctic has not been conducted. Here we test the expectation that CO2-enhanced gross primary production (GPP) may be temperature dependent, using data from several oceanographic cruises and experiments from both spring and summer in the European sector of the Arctic Ocean. Results confirm that CO2 enhances GPP (by a factor of up to ten) over a range of 145–2,099 μatm; however, the greatest effects are observed only at lower temperatures and are constrained by nutrient and light availability to the spring period. The temperature dependence of CO2-enhanced primary production has significant implications for metabolic balance in a warmer, CO2-enriched Arctic Ocean in the future. In particular, it indicates that a twofold increase in primary production during the spring is likely in the Arctic.

  5. Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication

    International Nuclear Information System (INIS)

    Dunck, Bárbara; Lima-Fernandes, Eva; Cássio, Fernanda; Cunha, Ana; Rodrigues, Liliana; Pascoal, Cláudia

    2015-01-01

    We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient. - Highlights: • Algae and decomposers discriminated the streams according to the eutrophication level. • Primary production and litter decomposition are stimulated by moderate eutrophication. • Biodiversity and process rates were reduced in highly eutrophic streams. • Subsidy-stress model explained biodiversity and process rates under eutrophication. - Rates of leaf litter decomposition, primary production and richness of periphytic algae, fungi and invertebrates were lower in streams at both ends of the trophic gradient

  6. Variation of phytoplankton biomass and primary production in Daya Bay during spring and summer

    International Nuclear Information System (INIS)

    Song Xingyu; Huang Liangmin; Zhang Jianlin; Huang, Xiaoping; Zhang Junbin; Yin Jianqiang; Tan Yehui; Liu Sheng

    2004-01-01

    Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m -3 in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mgC m -2 d -1 in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate in summer. Artificial impacts are evident from high temperature effluent from nuclear power stations, aquaculture and sewage. During the investigation, a red tide occurred in Aotou Bay, with a maximum Chl a of 103.23 mg m -3 at surface and primary production of 2721.9 mgC m -2 d -1 in the red tide center. Raised water temperature and nutrient supply from land-sources help to stimulate annual red tides

  7. Effect of surface state on the oxidation behavior of welded 308L in simulated nominal primary water of PWR

    Science.gov (United States)

    Ming, Hongliang; Zhang, Zhiming; Wang, Jiazhen; Zhu, Ruolin; Ding, Jie; Wang, Jianqiu; Han, En-Hou; Ke, Wei

    2015-05-01

    The oxidation behavior of 308L weld metal (WM) with different surface state in the simulated nominal primary water of pressurized water reactor (PWR) was studied by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) analyzer and X-ray photoelectron spectroscopy (XPS). After 480 h immersion, a duplex oxide film composed of a Fe-rich outer layer (Fe3O4, Fe2O3 and a small amount of NiFe2O4, Ni(OH)2, Cr(OH)3 and (Ni, Fe)Cr2O4) and a Cr-rich inner layer (FeCr2O4 and NiCr2O4) can be formed on the 308L WM samples with different surface state. The surface state has no influence on the phase composition of the oxide films but obviously affects the thickness of the oxide films and the morphology of the oxides (number & size). With increasing the density of dislocations and subgrain boundaries in the cold-worked superficial layer, the thickness of the oxide film, the number and size of the oxides decrease.

  8. Bradykinin stimulation of nitric oxide production is not sufficient for gamma-globin induction

    Directory of Open Access Journals (Sweden)

    Čokić Vladan P.

    2014-01-01

    Full Text Available Introduction. Hydroxycarbamide, used in therapy of hemoglobinopathies, enhances nitric oxide (NO production both in primary human umbilical vein endothelial cells (HUVECs and human bone marrow endothelial cell line (TrHBMEC. Moreover, NO increases γ-globin and fetal hemoglobin levels in human erythroid progenitors. Objective. In order to find out whether simple physiologic stimulation of NO production by components of hematopoietic microenvironment can increase γ-globin gene expression, the effects of NO-inducer bradykinin were examined in endothelial cells. Methods. The study was performed in co-cultures of human erythroid progenitors, TrHBMEC and HUVECs by ozone-based chemiluminescent determination of NO and real-time quantitative RT-PCR. Results. In accordance with previous reports, the endogenous factor bradykinin increased endothelial cell production of NO in a dose- and time-dependent manner (0.1-0.6 μM up to 30 minutes. This induction of NO in HUVECs and TrHBMEC by bradykinin was blocked by competitive inhibitors of NO synthase (NOS, demonstrating NOS-dependence. It has been shown that bradykinin significantly reduced endothelial NOS (eNOS mRNA level and eNOS/Я-actin ratio in HUVEC (by twofold. In addition, bradykinin failed to increase γ-globin mRNA expression in erythroid progenitors only, as well as in co-culture studies of erythroid progenitors with TrHBMEC and HUVEC after 24 hours of treatment. Furthermore, bradykinin did not induce γ/β globin ratio in erythroid progenitors in co-cultures with HUVEC. Conclusion. Bradykinin mediated eNOS activation leads to short time and low NO production in endothelial cells, insufficient to induce γ-globin gene expression. These results emphasized the significance of elevated and extended NO production in augmentation of γ-globin gene expression. [Projekat Ministarstva nauke Republike Srbije, br. 175053

  9. Production of nitric oxide using a microwave plasma torch and its application to fungal cell differentiation

    International Nuclear Information System (INIS)

    Na, Young Ho; Kang, Min-Ho; Cho, Guang Sup; Choi, Eun Ha; Park, Gyungsoon; Uhm, Han Sup; Kumar, Naresh

    2015-01-01

    The generation of nitric oxide by a microwave plasma torch is proposed for its application to cell differentiation. A microwave plasma torch was developed based on basic kinetic theory. The analytical theory indicates that nitric oxide density is nearly proportional to oxygen molecular density and that the high-temperature flame is an effective means of generating nitric oxide. Experimental data pertaining to nitric oxide production are presented in terms of the oxygen input in units of cubic centimeters per minute. The apparent length of the torch flame increases as the oxygen input increases. The various levels of nitric oxide are observed depending on the flow rate of nitrogen gas, the mole fraction of oxygen gas, and the microwave power. In order to evaluate the potential of nitric oxide as an activator of cell differentiation, we applied nitric oxide generated from the microwave plasma torch to a model microbial cell (Neurospora crassa: non-pathogenic fungus). Germination and hyphal differentiation of fungal cells were not dramatically changed but there was a significant increase in spore formation after treatment with nitric oxide. In addition, the expression level of a sporulation related gene acon-3 was significantly elevated after 24 h upon nitric oxide treatment. Increase in the level of nitric oxide, nitrite and nitrate in water after nitric oxide treatment seems to be responsible for activation of fungal sporulation. Our results suggest that nitric oxide generated by plasma can be used as a possible activator of cell differentiation and development. (paper)

  10. Biodiesel Production from Castor Oil by Using Calcium Oxide Derived from Mud Clam Shell

    OpenAIRE

    Ismail, S.; Ahmed, A. S.; Anr, Reddy; Hamdan, S.

    2016-01-01

    The catalytic potential of calcium oxide synthesized from mud clam shell as a heterogeneous catalyst for biodiesel production was studied. The mud clam shell calcium oxide was characterized using particle size analyzer, Fourier transform infrared spectroscopy, scanning electron microscopy, and BET gas sorption analyzer. The catalyst performance of mud clam shell calcium oxide was studied in the transesterification of castor oil as biodiesel. Catalyst characterization and transesterification s...

  11. Interview and questionnaire guide: Quantification of food losses and waste in primary production

    DEFF Research Database (Denmark)

    Svanes, Erik; Hartikainen, Hanna; Mogensen, Lisbeth

    production in the Nordic countries. Other aims were to estimate the amount of side flow and to gain knowledge about the reasons behind it, how it can be reduced, how it is treated and how it can be better utilized.This guide contains a catalogue of questions that may be used for interviews and questionnaires...... with primary producers and other stakeholders within primary production. It also contains the justification behind the questions and some tips on how to conduct interviews.......This interview guide was developed within the Nordic project “Food losses and waste in primary production” (Franke et al. 2016). One of the main purposes of the project was to test research methods for the quantification of food losses and waste (in the project called 'side flow') from primary...

  12. Experimental and theoretical understanding of the gas phase oxidation of atmospheric amides with OH radicals: kinetics, products, and mechanisms.

    Science.gov (United States)

    Borduas, Nadine; da Silva, Gabriel; Murphy, Jennifer G; Abbatt, Jonathan P D

    2015-05-14

    Atmospheric amides have primary and secondary sources and are present in ambient air at low pptv levels. To better assess the fate of amides in the atmosphere, the room temperature (298 ± 3 K) rate coefficients of five different amides with OH radicals were determined in a 1 m(3) smog chamber using online proton-transfer-reaction mass spectrometry (PTR-MS). Formamide, the simplest amide, has a rate coefficient of (4.44 ± 0.46) × 10(-12) cm(3) molec(-1) s(-1) against OH, translating to an atmospheric lifetime of ∼1 day. N-methylformamide, N-methylacetamide and propanamide, alkyl versions of formamide, have rate coefficients of (10.1 ± 0.6) × 10(-12), (5.42 ± 0.19) × 10(-12), and (1.78 ± 0.43) × 10(-12) cm(3) molec(-1) s(-1), respectively. Acetamide was also investigated, but due to its slow oxidation kinetics, we report a range of (0.4-1.1) × 10(-12) cm(3) molec(-1) s(-1) for its rate coefficient with OH radicals. Oxidation products were monitored and quantified and their time traces were fitted using a simple kinetic box model. To further probe the mechanism, ab initio calculations are used to identify the initial radical products of the amide reactions with OH. Our results indicate that N-H abstractions are negligible in all cases, in contrast to what is predicted by structure-activity relationships. Instead, the reactions proceed via C-H abstraction from alkyl groups and from formyl C(O)-H bonds when available. The latter process leads to radicals that can readily react with O2 to form isocyanates, explaining the detection of toxic compounds such as isocyanic acid (HNCO) and methyl isocyanate (CH3NCO). These contaminants of significant interest are primary oxidation products in the photochemical oxidation of formamide and N-methylformamide, respectively.

  13. Bromide-free TEMPO-mediated oxidation of primary alcohol groups in starch and methyl alpha-D-glucopyranoside.

    Science.gov (United States)

    Bragd, P L; Besemer, A C; van Bekkum, H

    2000-09-22

    TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)-mediated oxidation of potato starch and methyl alpha-D-glucopyranoside (MGP) was performed in the absence of sodium bromide (NaBr) as co-catalyst, solely using sodium hypochlorite (NaOCl) as the primary oxidant. The low reaction rate associated with a bromide-free process was increased by performing the oxidation at increased temperatures. The reaction proceeded stoichiometrically and with high selectivity and with only minor depolymerisation, provided that temperature and pH were kept or = 25 degrees C) and under more alkaline conditions (pH > or = 9.0) degradation of the starch skeleton occurred. Simultaneously, side-reactions of the nitrosonium ion lowered the yield of the oxidation. Despite the absence of the NaBr catalyst, the reaction rate-controlling step was found to be the oxidation of the primary hydroxyl groups with the nitrosonium ion. The reaction was first-order in MGP and in TEMPO.

  14. Rapid Removal of Tetrabromobisphenol A by Ozonation in Water: Oxidation Products, Reaction Pathways and Toxicity Assessment.

    Directory of Open Access Journals (Sweden)

    Ruijuan Qu

    Full Text Available Tetrabromobisphenol A (TBBPA is one of the most widely used brominated flame retardants and has attracted more and more attention. In this work, the parent TBBPA with an initial concentration of 100 mg/L was completely removed after 6 min of ozonation at pH 8.0, and alkaline conditions favored a more rapid removal than acidic and neutral conditions. The presence of typical anions and humic acid did not significantly affect the degradation of TBBPA. The quenching test using isopropanol indicated that direct ozone oxidation played a dominant role during this process. Seventeen reaction intermediates and products were identified using an electrospray time-of-flight mass spectrometer. Notably, the generation of 2,4,6-tribromophenol was first observed in the degradation process of TBBPA. The evolution of reaction products showed that ozonation is an efficient treatment for removal of both TBBPA and intermediates. Sequential transformation of organic bromine to bromide and bromate was confirmed by ion chromatography analysis. Two primary reaction pathways that involve cleavage of central carbon atom and benzene ring cleavage concomitant with debromination were thus proposed and further justified by calculations of frontier electron densities. Furthermore, the total organic carbon data suggested a low mineralization rate, even after the complete removal of TBBPA. Meanwhile, the acute aqueous toxicity of reaction solutions to Photobacterium Phosphoreum and Daphnia magna was rapidly decreased during ozonation. In addition, no obvious difference in the attenuation of TBBPA was found by ozone oxidation using different water matrices, and the effectiveness in natural waters further demonstrates that ozonation can be adopted as a promising technique to treat TBBPA-contaminated waters.

  15. Rapid Removal of Tetrabromobisphenol A by Ozonation in Water: Oxidation Products, Reaction Pathways and Toxicity Assessment

    Science.gov (United States)

    Wang, Xinghao; Huang, Qingguo; Lu, Junhe; Wang, Liansheng; Wang, Zunyao

    2015-01-01

    Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and has attracted more and more attention. In this work, the parent TBBPA with an initial concentration of 100 mg/L was completely removed after 6 min of ozonation at pH 8.0, and alkaline conditions favored a more rapid removal than acidic and neutral conditions. The presence of typical anions and humic acid did not significantly affect the degradation of TBBPA. The quenching test using isopropanol indicated that direct ozone oxidation played a dominant role during this process. Seventeen reaction intermediates and products were identified using an electrospray time-of-flight mass spectrometer. Notably, the generation of 2,4,6-tribromophenol was first observed in the degradation process of TBBPA. The evolution of reaction products showed that ozonation is an efficient treatment for removal of both TBBPA and intermediates. Sequential transformation of organic bromine to bromide and bromate was confirmed by ion chromatography analysis. Two primary reaction pathways that involve cleavage of central carbon atom and benzene ring cleavage concomitant with debromination were thus proposed and further justified by calculations of frontier electron densities. Furthermore, the total organic carbon data suggested a low mineralization rate, even after the complete removal of TBBPA. Meanwhile, the acute aqueous toxicity of reaction solutions to Photobacterium Phosphoreum and Daphnia magna was rapidly decreased during ozonation. In addition, no obvious difference in the attenuation of TBBPA was found by ozone oxidation using different water matrices, and the effectiveness in natural waters further demonstrates that ozonation can be adopted as a promising technique to treat TBBPA-contaminated waters. PMID:26430733

  16. Efficient internalization of silica-coated iron oxide nanoparticles of different sizes by primary human macrophages and dendritic cells

    International Nuclear Information System (INIS)

    Kunzmann, Andrea; Andersson, Britta; Vogt, Carmen; Feliu, Neus; Ye Fei; Gabrielsson, Susanne; Toprak, Muhammet S.; Buerki-Thurnherr, Tina; Laurent, Sophie; Vahter, Marie; Krug, Harald; Muhammed, Mamoun; Scheynius, Annika; Fadeel, Bengt

    2011-01-01

    Engineered nanoparticles are being considered for a wide range of biomedical applications, from magnetic resonance imaging to 'smart' drug delivery systems. The development of novel nanomaterials for biomedical applications must be accompanied by careful scrutiny of their biocompatibility. In this regard, particular attention should be paid to the possible interactions between nanoparticles and cells of the immune system, our primary defense system against foreign invasion. On the other hand, labeling of immune cells serves as an ideal tool for visualization, diagnosis or treatment of inflammatory processes, which requires the efficient internalization of the nanoparticles into the cells of interest. Here, we compare novel monodispersed silica-coated iron oxide nanoparticles with commercially available dextran-coated iron oxide nanoparticles. The silica-coated iron oxide nanoparticles displayed excellent magnetic properties. Furthermore, they were non-toxic to primary human monocyte-derived macrophages at all doses tested whereas dose-dependent toxicity of the smaller silica-coated nanoparticles (30 nm and 50 nm) was observed for primary monocyte-derived dendritic cells, but not for the similarly small dextran-coated iron oxide nanoparticles. No macrophage or dendritic cell secretion of pro-inflammatory cytokines was observed upon administration of nanoparticles. The silica-coated iron oxide nanoparticles were taken up to a significantly higher degree when compared to the dextran-coated nanoparticles, irrespective of size. Cellular internalization of the silica-coated nanoparticles was through an active, actin cytoskeleton-dependent process. We conclude that these novel silica-coated iron oxide nanoparticles are promising materials for medical imaging, cell tracking and other biomedical applications.

  17. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Gustavsson, Leif [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  18. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    International Nuclear Information System (INIS)

    Sathre, Roger; Gustavsson, Leif; Bergh, Johan

    2010-01-01

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO 2equiv if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  19. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission. (author)

  20. Method and apparatus for the production of metal oxide powder

    Science.gov (United States)

    Harris, Michael T.; Scott, Timothy C.; Byers, Charles H.

    1992-01-01

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

  1. Catalytic production of metal carbonyls from metal oxides

    Science.gov (United States)

    Sapienza, Richard S.; Slegeir, William A.; Foran, Michael T.

    1984-01-01

    This invention relates to the formation of metal carbonyls from metal oxides and specially the formation of molybdenum carbonyl and iron carbonyl from their respective oxides. Copper is used here in admixed form or used in chemically combined form as copper molybdate. The copper/metal oxide combination or combined copper is utilized with a solvent, such as toluene and subjected to carbon monoxide pressure of 25 atmospheres or greater at about 150.degree.-260.degree. C. The reducing metal copper is employed in catalytic concentrations or combined concentrations as CuMoO.sub.4 and both hydrogen and water present serve as promoters. It has been found that the yields by this process have been salutary and that additionally the catalytic metal may be reused in the process to good effect.

  2. Method and apparatus for the production of metal oxide powder

    Science.gov (United States)

    Harris, M.T.; Scott, T.C.; Byers, C.H.

    1992-06-16

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed. 2 figs.

  3. Primary production in a shallow water lake with special reference to a reed swamp

    International Nuclear Information System (INIS)

    Andersen, F.Oe.

    1976-01-01

    Phytoplankton gross primary production ( 14 C method) in the shallow, eutrophic Danish Lake Arresoe in 1973 was 980 g C m -2 . Calculated net primary production was near zero. Macrophyte net primary production was measured by harvesting the maximum biomass, and above ground values were between 420 and 1325 g ash free dry wt m -2 , while below ground values were between 2480 and 8570 g ash free dry wt m -2 . The reed swamps were mapped on aerial photographs, and the composition of the macrophyte vegetation was determined. A comparison of macrophyte vegetation in 1944 and 1972 showed a reduction in species diversity, especially of submerged species. The seasonal variations in physical and chemical data indicated strong eutrophication in Arresoe. (author)

  4. Enhancing Biodiesel Production Using Green Glycerol-Enriched Calcium Oxide Catalyst : An Optimization Study

    NARCIS (Netherlands)

    Avhad, Mangesh R.; Gangurde, L.S.; Sánchez, Marcos; Bouaid, Abderrahim; Aracil, José; Martínez, Mercedes; Marchetti, Jorge M.

    2018-01-01

    The present article demonstrates a superior catalytic performance of glycerol-enriched calcium oxide for biodiesel production than other calcium-based counterparts. The proficiency of glycerol-enriched calcium oxide in catalyzing the methanolysis of crude Jatropha curcas oil containing high free

  5. The degradation of lining of rotary furnaces in the production of zinc oxide

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Pešlová, F.; Anisimov, E.

    2014-01-01

    Roč. 21, č. 3 (2014), s. 116-121 ISSN 1335-0803 Institutional support: RVO:68081723 Keywords : zinc oxide * the production of zinc oxide * zinc slag * refractories * the degradation of rotary furnace linings Subject RIV: JG - Metallurgy http://ojs.mateng.sk/index.php/Mateng/article/view/133/194

  6. Continuous operation of a pilot plant for the production of beryllium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Costa, T C; Amaral, S; Silveira, C M.S.; de Oliveira, A P [Instituto de Tecnologia, Governador Valadares (Brazil)

    1975-12-01

    A method of obtaining beryllium oxide with a purity of 99,2% was developed in a pilot plant with a capacity of 7 tons per month destined to operate continuously. The operation market prospects and control of production with the objective of obtaining internacional technical grade beryllium oxide are discussed.

  7. Continuous operation of a pilot plant for the production of beryllium oxide

    International Nuclear Information System (INIS)

    Costa, T.C.; Amaral, S.; Silveira, C.M.S.; Oliveira, A.P. de

    1975-01-01

    A method of obtaining beryllium oxide with a purity of 99,2% was developed in a pilot plant with a capacity of 7 tons per month destined to operate continuously. The operation market prospects and control of production with the objective of obtaining internacional technical grade beryllium oxide are discussed [pt

  8. Impact of residual elements on zinc quality in the production of zinc oxide

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Dymáček, Petr; Pešlová, F.; Jurkovič, Z.; Barborák, O.; Stodola, J.

    2016-01-01

    Roč. 55, č. 3 (2016), s. 407-410 ISSN 0543-5846 Institutional support: RVO:68081723 Keywords : zinc * metallography * microstructure of zinc * zinc oxide * production of zinc oxide Subject RIV: JG - Metallurgy Impact factor: 0.959, year: 2014

  9. Oxidation using quaternary ammonium polyhalides VII. Oxidation of primary amines and hydrazo compounds by use of benzyltrimethylammonium tribromide

    OpenAIRE

    Nishida, Akiko; Kohro, Noriaki; Fujisaki, Shizuo; Kajigaeshi, Shoji

    1990-01-01

    The reactions of primary amines and hydrazo compounds with benzyltrimethylammonium tribromide in aqueous sodium hydroxide or in water gave the corresponding nitriles and azo compounds in satisfactory yields, respectively.

  10. Formation and occurrence of dimer esters of pinene oxidation products in atmospheric aerosols

    DEFF Research Database (Denmark)

    Kristensen, Kasper; Enggrob, Kirsten L.; King, S. M.

    2013-01-01

    products cis-pinic and terpenylic acids, but similar to the second-generation oxidation products 3-methyl-1,2,3-butane tricarboxylic acid (MBTCA) and diaterpenylic acid acetate (DTAA). Dimer esters were observed within the first 30 min, indicating rapid production simultaneous to their structural...

  11. Nitrous oxide production in grassland soils: assessing the contribution of nitrifier denitrification

    NARCIS (Netherlands)

    Wrage, N.; Velthof, G.L.; Laanbroek, H.J.; Oenema, O.

    2004-01-01

    Nitrifier denitrification is the reduction of NO2- to N2 by nitrifiers. It leads to the production of the greenhouse gas nitrous oxide (N2O) as an intermediate and possible end product. It is not known how important nitrifier denitrification is for the production of N2O in soils. We explored N2O

  12. Corrosion product behaviour in the primary circuit of the KNK nuclear reactor facility

    International Nuclear Information System (INIS)

    Stamm, H.H.; Stade, K.Ch.

    1976-01-01

    During nuclear operation of the KNK facility from 1972 until September 1974 the composition and behaviour of radionuclides occuring in the primary circuit were investigated. Besides traces of 140 Ba/ 140 La, no fission product activity was detectable in the KNK primary circuit. The fuel element purification from sodium deposits (prior to transport to the reprocessing plant) did not yield any indication of a fuel element failure during KNK-I operation. The activity inventory of the primary loop was exclusively made up of activated corrosion products and 22 Na. The main activity was due to 65 Zn, followed by 54 Mn, 22 Na, sup(110m)Ag, 182 Ta, 60 Co and 124 Sb. It was found that the sorption of 65 Zn and 54 Mn on crucibles made from nickel was condiserably higher than on vessels made from other materials. This observation was confirmed both in tests with material samples from the primary circuit and for disks of gate valves of the primary circuit. sup(110m)Ag did hardly exhibit any sorption effects and had been dissolved largely homogeneously in the hot primary coolant. In the first primary cold trap which was removed from the circuit after some 20,000 hours of operation, only 65 Zn and 54 Mn were detected in addition to traces of 60 Co and 182 Ta. (author)

  13. Denitrification: An important pathway for nitrous oxide production in tropical mangrove sediments (Goa, India)

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, S.O.; LokaBharathi, P.A.; Bonin, P.C.; Michotey, V.D.

    Net nitrous oxide production and denitrification activity were measured in two mangrove ecosystems of Goa, India. The relatively pristine site Tuvem was compared to Divar, which is prone to high nutrient input. Stratified sampling at 2-cm intervals...

  14. Piper sarmentosum increases nitric oxide production in oxidative stress: a study on human umbilical vein endothelial cells.

    Science.gov (United States)

    Ugusman, Azizah; Zakaria, Zaiton; Hui, Chua Kien; Nordin, Nor Anita Megat Mohd

    2010-07-01

    Nitric oxide produced by endothelial nitric oxide synthase (eNOS) possesses multiple anti-atherosclerotic properties. Hence, enhanced expression of eNOS and increased Nitric oxide levels may protect against the development of atherosclerosis. Piper sarmentosum is a tropical plant with antioxidant and anti-inflammatory activities. This study aimed to investigate the effects of Piper sarmentosum on the eNOS and Nitric oxide pathway in cultured human umbilical vein endothelial cells (HUVECs). HUVECS WERE DIVIDED INTO FOUR GROUPS: control, treatment with 180 microM hydrogen peroxide (H(2)O(2)), treatment with 150 microg/mL aqueous extract of Piper sarmentosum, and concomitant treatment with aqueous extract of PS and H(2)O(2) for 24 hours. Subsequently, HUVECs were harvested and eNOS mRNA expression was determined using qPCR. The eNOS protein level was measured using ELISA, and the eNOS activity and Nitric oxide level were determined by the Griess reaction. Human umbilical vein endothelial cells treated with aqueous extract of Piper sarmentosum showed a marked induction of Nitric oxide. Treatment with PS also resulted in increased eNOS mRNA expression, eNOS protein level and eNOS activity in HUVECs. Aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs.

  15. Piper sarmentosum increases nitric oxide production in oxidative stress: a study on human umbilical vein endothelial cells

    Directory of Open Access Journals (Sweden)

    Azizah Ugusman

    2010-01-01

    Full Text Available OBJECTIVE: Nitric oxide produced by endothelial nitric oxide synthase (eNOS possesses multiple anti-atherosclerotic properties. Hence, enhanced expression of eNOS and increased Nitric oxide levels may protect against the development of atherosclerosis. Piper sarmentosum is a tropical plant with antioxidant and anti-inflammatory activities. This study aimed to investigate the effects of Piper sarmentosum on the eNOS and Nitric oxide pathway in cultured human umbilical vein endothelial cells (HUVECs. METHODS: HUVECs were divided into four groups: control, treatment with 180 μM hydrogen peroxide (H2O2, treatment with 150 μg/mL aqueous extract of Piper sarmentosum, and concomitant treatment with aqueous extract of PS and H2O2 for 24 hours. Subsequently, HUVECs were harvested and eNOS mRNA expression was determined using qPCR. The eNOS protein level was measured using ELISA, and the eNOS activity and Nitric oxide level were determined by the Griess reaction. RESULTS: Human umbilical vein endothelial cells treated with aqueous extract of Piper sarmentosum showed a marked induction of Nitric oxide. Treatment with PS also resulted in increased eNOS mRNA expression, eNOS protein level and eNOS activity in HUVECs. CONCLUSION: Aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs.

  16. Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction.

    Science.gov (United States)

    Hansel, Colleen M; Zeiner, Carolyn A; Santelli, Cara M; Webb, Samuel M

    2012-07-31

    Manganese (Mn) oxides are among the most reactive minerals within the environment, where they control the bioavailability of carbon, nutrients, and numerous metals. Although the ability of microorganisms to oxidize Mn(II) to Mn(III/IV) oxides is scattered throughout the bacterial and fungal domains of life, the mechanism and physiological basis for Mn(II) oxidation remains an enigma. Here, we use a combination of compound-specific chemical assays, microspectroscopy, and electron microscopy to show that a common Ascomycete filamentous fungus, Stilbella aciculosa, oxidizes Mn(II) to Mn oxides by producing extracellular superoxide during cell differentiation. The reactive Mn oxide phase birnessite and the reactive oxygen species superoxide and hydrogen peroxide are colocalized at the base of asexual reproductive structures. Mn oxide formation is not observed in the presence of superoxide scavengers (e.g., Cu) and inhibitors of NADPH oxidases (e.g., diphenylene iodonium chloride), enzymes responsible for superoxide production and cell differentiation in fungi. Considering the recent identification of Mn(II) oxidation by NADH oxidase-based superoxide production by a common marine bacterium (Roseobacter sp.), these results introduce a surprising homology between some prokaryotic and eukaryotic organisms in the mechanisms responsible for Mn(II) oxidation, where oxidation appears to be a side reaction of extracellular superoxide production. Given the versatility of superoxide as a redox reactant and the widespread ability of fungi to produce superoxide, this microbial extracellular superoxide production may play a central role in the cycling and bioavailability of metals (e.g., Hg, Fe, Mn) and carbon in natural systems.

  17. Pitfalls in measuring nitrous oxide production by nitrifiers

    NARCIS (Netherlands)

    Wrage, N.

    2003-01-01

    Nitrous oxide (N 2 O) is an important greenhouse gas. At present, it causes 6% of global warming. The atmospheric concentration of N 2 O continues to increase at a rate of 0.8 ppb per year. The main known sink of N 2 O is its destruction in the stratosphere to

  18. Serum Iron and Nitric Oxide Production in Trypanosoma brucei ...

    African Journals Online (AJOL)

    JTEkanem

    reduction in the serum iron status and a modulation of nitric oxide synthase activity of T. brucei infected rats. ... inflammation and tissue damage15. ... The serum iron level was determined ... concentration or of total nitrate and nitrite ... 15. 16. 17. 18. Days. S e ru m iro n lev e l mg. /ml. Infected treated. Infected untreated. 0.

  19. Mean annual precipitation predicts primary production resistance and resilience to extreme drought.

    Science.gov (United States)

    Stuart-Haëntjens, Ellen; De Boeck, Hans J; Lemoine, Nathan P; Mänd, Pille; Kröel-Dulay, György; Schmidt, Inger K; Jentsch, Anke; Stampfli, Andreas; Anderegg, William R L; Bahn, Michael; Kreyling, Juergen; Wohlgemuth, Thomas; Lloret, Francisco; Classen, Aimée T; Gough, Christopher M; Smith, Melinda D

    2018-04-27

    Extreme drought is increasing in frequency and intensity in many regions globally, with uncertain consequences for the resistance and resilience of ecosystem functions, including primary production. Primary production resistance, the capacity to withstand change during extreme drought, and resilience, the degree to which production recovers, vary among and within ecosystem types, obscuring generalized patterns of ecological stability. Theory and many observations suggest forest production is more resistant but less resilient than grassland production to extreme drought; however, studies of production sensitivity to precipitation variability indicate that the processes controlling resistance and resilience may be influenced more by mean annual precipitation (MAP) than ecosystem type. Here, we conducted a global meta-analysis to investigate primary production resistance and resilience to extreme drought in 64 forests and grasslands across a broad MAP gradient. We found resistance to extreme drought was predicted by MAP; however, grasslands (positive) and forests (negative) exhibited opposing resilience relationships with MAP. Our findings indicate that common plant physiological mechanisms may determine grassland and forest resistance to extreme drought, whereas differences among plant residents in turnover time, plant architecture, and drought adaptive strategies likely underlie divergent resilience patterns. The low resistance and resilience of dry grasslands suggests that these ecosystems are the most vulnerable to extreme drought - a vulnerability that is expected to compound as extreme drought frequency increases in the future. Copyright © 2018. Published by Elsevier B.V.

  20. Nitrous oxide production by lithotrophic ammonia-oxidizing bacteria and implications for engineered nitrogen-removal systems.

    Science.gov (United States)

    Chandran, Kartik; Stein, Lisa Y; Klotz, Martin G; van Loosdrecht, Mark C M

    2011-12-01

    Chemolithoautotrophic AOB (ammonia-oxidizing bacteria) form a crucial component in microbial nitrogen cycling in both natural and engineered systems. Under specific conditions, including transitions from anoxic to oxic conditions and/or excessive ammonia loading, and the presence of high nitrite (NO₂⁻) concentrations, these bacteria are also documented to produce nitric oxide (NO) and nitrous oxide (N₂O) gases. Essentially, ammonia oxidation in the presence of non-limiting substrate concentrations (ammonia and O₂) is associated with N₂O production. An exceptional scenario that leads to such conditions is the periodical switch between anoxic and oxic conditions, which is rather common in engineered nitrogen-removal systems. In particular, the recovery from, rather than imposition of, anoxic conditions has been demonstrated to result in N₂O production. However, applied engineering perspectives, so far, have largely ignored the contribution of nitrification to N₂O emissions in greenhouse gas inventories from wastewater-treatment plants. Recent field-scale measurements have revealed that nitrification-related N₂O emissions are generally far higher than emissions assigned to heterotrophic denitrification. In the present paper, the metabolic pathways, which could potentially contribute to NO and N₂O production by AOB have been conceptually reconstructed under conditions especially relevant to engineered nitrogen-removal systems. Taken together, the reconstructed pathways, field- and laboratory-scale results suggest that engineering designs that achieve low effluent aqueous nitrogen concentrations also minimize gaseous nitrogen emissions.

  1. Does increased Nitric Oxide production and oxidative stress due to high fat diet affect cardiac function after myocardial infarction?

    Directory of Open Access Journals (Sweden)

    Marjan Aghajani

    2017-01-01

    Full Text Available Background &Objectives: High fat (HF diet by affecting the oxidative stress and nitric oxide (NO production may lead to different effects on function of the heart after myocardial infarction (MI. In the present study we aimed to address the hypothesis that high release of NO by activated macrophages affects LV function after MI.Methods: The animals were randomly divided into four groups comprising each of 10 rats: 1 Sham; 2 MI; 3 Sham+ HF diet; 4 MI+ HF diet. Animals fed with HF diet 30 days before sham and MI surgery. MI was induced by permanent ligation of left anterior descending coronary artery (LAD. Nitric oxide (NO production of peritoneal macrophages, the concentrations of MDA in the heart and the infarct size were measured.Results: Our study indicated that HF has adverse effects on myocardium and it may increase NO production as well as oxidative stress, resulting in augmentation of infarct size.Conclusion: Our results add to our knowledge that HF diet was associated with overproduction of NO by peritoneal macrophages and ROS that lead to development of infarct size and adverse remodeling.

  2. Hydrodeoxygenation of oxidized distilled bio-oil for the production of gasoline fuel type

    International Nuclear Information System (INIS)

    Luo, Yan; Guda, Vamshi Krishna; Hassan, El Barbary; Steele, Philip H.; Mitchell, Brian; Yu, Fei

    2016-01-01

    Highlights: • Oxidation had more influence on the yield of total hydrocarbons than distillation. • The highest total hydrocarbon yield was obtained from oxidized distilled bio-oil. • The 2nd-stage hydrocarbons were in the range of gasoline fuel boiling points. • The main products for upgrading of oxidized bio-oil were aliphatic hydrocarbons. • The main products for upgrading of non-oxidized bio-oil were aromatic hydrocarbons. - Abstract: Distilled and oxidized distilled bio-oils were subjected to 1st-stage mild hydrodeoxygenation and 2nd-stage full hydrodeoxygenation using nickel/silica–alumina catalyst as a means to enhance hydrocarbon yield. Raw bio-oil was treated for hydrodeoxygenation as a control to which to compare study treatments. Following two-stage hydrodeoxygenation, four types of hydrocarbons were mainly comprised of gasoline and had water contents, oxygen contents and total acid numbers of nearly zero and higher heating values of 44–45 MJ/kg. Total hydrocarbon yields for raw bio-oil, oxidized raw bio-oil, distilled bio-oil and oxidized distilled bio-oil were 11.6, 16.2, 12.9 and 20.5 wt.%, respectively. The results indicated that oxidation had the most influence on increasing the yield of gasoline fuel type followed by distillation. Gas chromatography/mass spectrometry characterization showed that 66.0–76.6% of aliphatic hydrocarbons and 19.5–31.6% of aromatic hydrocarbons were the main products for oxidized bio-oils while 35.5–38.7% of aliphatic hydrocarbons and 58.2–63.1% of aromatic hydrocarbons were the main products for non-oxidized bio-oils. Both aliphatic and aromatic hydrocarbons are important components for liquid transportation fuels and chemical products.

  3. Characterisation of Oxides Formed on the Internal Surface of Steam Generator Tubes in Alloy 690 Corroded in the Primary Environment of Pressurised Water Reactors

    International Nuclear Information System (INIS)

    Carrette, Florence; Leclercq, Stephanie; Legras, Laurent

    2012-09-01

    Since the end of the 1990s, EDF R and D has been studying the phenomenon of corrosion product release from Steam Generator tubes in order to minimize the Source Term of the contamination and radiation exposure during operation and maintenance of Pressurised Water Reactors. With the BOREAL loop, release tests in primary water at 325 deg. C were performed on various Steam Generator tubes made of alloy 690. The experimental conditions of these tests (chemistry, temperature and hydraulics) were the same for all the tests but the results showed various behaviours towards release. For some tubes, the release was weak whereas for others, it was higher; the release rate of the tubes decreased more or less quickly with time. In order to explain these results, the internal surface of the tubes was characterised before and after the tests. Before the tests, various parameters were studied; the main parameters were the roughness, the impurities, the grain size and the cold work. The results demonstrated that it was not easy to quantify the influence of each parameter on release and to differentiate the tubes. A new parameter was proposed to characterise the internal extreme surface of SG tubes: the surface nano-hardness by nano-indentation measurements. The tubes were also observed and analysed by SEM, (X)TEM. Data obtained by (X)TEM revealed differences of the surface state (layer of perturbed microstructure, density of dislocations, grain size, impurities, initial oxide,...). After the tests, the oxides formed on the internal surface and the underlying material of the samples were characterised by SEM, (X)TEM and SIMS. The examinations showed various types of oxides. For some tubes, a duplex oxide scale was identified, for the others, only one oxide scale was observed. For equivalent durations of corrosion, the thickness of the enriched - chromium oxide layer can vary from 5 nm to 100 nm and the chemical composition can be different. The examinations of the underlying

  4. Intensity of lipid oxidation and formation of cholesterol oxidation products during frozen storage of raw and cooked chicken

    OpenAIRE

    Conchillo, A. (Ana); Ansorena, D. (Diana); Astiasarán, I. (Iciar)

    2004-01-01

    Raw and cooked chicken breasts were stored at −18 °C for 3 months under aerobic and vacuum conditions, and the intensity of lipid oxidation and the formation of COP (cholesterol oxidation products) were studied. Raw samples showed low COP levels (4.60–7.40 µg g−1 fat), TBARS (thiobarbituric acid reactive substances) levels (0.01–0.03 mg kg−1) and peroxide values (not detected) under both aerobic and vacuum conditions. Cooked samples (grilled and roasted) showed TBARS levels of 0.36–0.99 mg kg...

  5. Food waste quantification in primary production - The Nordic countries as a case study.

    Science.gov (United States)

    Hartikainen, Hanna; Mogensen, Lisbeth; Svanes, Erik; Franke, Ulrika

    2018-01-01

    Our understanding of food waste in the food supply chain has increased, but very few studies have been published on food waste in primary production. The overall aims of this study were to quantify the total amount of food waste in primary production in Finland, Sweden, Norway and Denmark, and to create a framework for how to define and quantify food waste in primary production. The quantification of food waste was based on case studies conducted in the present study and estimates published in scientific literature. The chosen scope of the study was to quantify the amount of edible food (excluding inedible parts like peels and bones) produced for human consumption that did not end up as food. As a result, the quantification was different from the existing guidelines. One of the main differences is that food that ends up as animal feed is included in the present study, whereas this is not the case for the recently launched food waste definition of the FUSIONS project. To distinguish the 'food waste' definition of the present study from the existing definitions and to avoid confusion with established usage of the term, a new term 'side flow' (SF) was introduced as a synonym for food waste in primary production. A rough estimate of the total amount of food waste in primary production in Finland, Sweden, Norway and Denmark was made using SF and 'FUSIONS Food Waste' (FFW) definitions. The SFs in primary production in the four Nordic countries were an estimated 800,000 tonnes per year with an additional 100,000 tonnes per year from the rearing phase of animals. The 900,000 tonnes per year of SF corresponds to 3.7% of the total production of 24,000,000 tonnes per year of edible primary products. When using the FFW definition proposed by the FUSIONS project, the FFW amount was estimated at 330,000 tonnes per year, or 1% of the total production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Secondary organic aerosol production from pinanediol, a semi-volatile surrogate for first-generation oxidation products of monoterpenes

    Science.gov (United States)

    Ye, Penglin; Zhao, Yunliang; Chuang, Wayne K.; Robinson, Allen L.; Donahue, Neil M.

    2018-05-01

    We have investigated the production of secondary organic aerosol (SOA) from pinanediol (PD), a precursor chosen as a semi-volatile surrogate for first-generation oxidation products of monoterpenes. Observations at the CLOUD facility at CERN have shown that oxidation of organic compounds such as PD can be an important contributor to new-particle formation. Here we focus on SOA mass yields and chemical composition from PD photo-oxidation in the CMU smog chamber. To determine the SOA mass yields from this semi-volatile precursor, we had to address partitioning of both the PD and its oxidation products to the chamber walls. After correcting for these losses, we found OA loading dependent SOA mass yields from PD oxidation that ranged between 0.1 and 0.9 for SOA concentrations between 0.02 and 20 µg m-3, these mass yields are 2-3 times larger than typical of much more volatile monoterpenes. The average carbon oxidation state measured with an aerosol mass spectrometer was around -0.7. We modeled the chamber data using a dynamical two-dimensional volatility basis set and found that a significant fraction of the SOA comprises low-volatility organic compounds that could drive new-particle formation and growth, which is consistent with the CLOUD observations.

  7. Potential consequences of climate change for primary production and fish production in large marine ecosystems.

    Science.gov (United States)

    Blanchard, Julia L; Jennings, Simon; Holmes, Robert; Harle, James; Merino, Gorka; Allen, J Icarus; Holt, Jason; Dulvy, Nicholas K; Barange, Manuel

    2012-11-05

    Existing methods to predict the effects of climate change on the biomass and production of marine communities are predicated on modelling the interactions and dynamics of individual species, a very challenging approach when interactions and distributions are changing and little is known about the ecological mechanisms driving the responses of many species. An informative parallel approach is to develop size-based methods. These capture the properties of food webs that describe energy flux and production at a particular size, independent of species' ecology. We couple a physical-biogeochemical model with a dynamic, size-based food web model to predict the future effects of climate change on fish biomass and production in 11 large regional shelf seas, with and without fishing effects. Changes in potential fish production are shown to most strongly mirror changes in phytoplankton production. We project declines of 30-60% in potential fish production across some important areas of tropical shelf and upwelling seas, most notably in the eastern Indo-Pacific, the northern Humboldt and the North Canary Current. Conversely, in some areas of the high latitude shelf seas, the production of pelagic predators was projected to increase by 28-89%.

  8. Warming Increases the Proportion of Primary Production Emitted as Methane from Freshwater Mesocosms

    OpenAIRE

    2010-01-01

    Abstract Methane and carbon dioxide are the dominant gaseous end products of the remineralisation of organic carbon and also the two largest contributors to the anthropogenic greenhouse effect. We investigated whether warming altered the balance of methane efflux relative to primary production and ecosystem respiration in a freshwater mesocosm experiment. Whole ecosystem CH4 efflux was strongly related to temperature with an apparent activation energy of 0.85eV. Furthermore, CH4 ef...

  9. An economic route to mass production of graphene oxide solution for preparing graphene oxide papers

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Yan-Jia; Tsai, Bo-Da; Huang, Wu-Jang, E-mail: wjhuang@mail.npust.edu.tw

    2015-03-15

    Highlights: • Graphene oxide paper can be prepared from synthesized graphene sheet containing carbon materials. • Graphene oxide paper can be used as a phase change materials for thermal storage. • To prepare graphene oxide paper from synthesized graphene sheet containing carbon materials could highly reduce the cost. - Abstract: Graphene oxide paper (GOP) is a composite material fabricated from graphene oxide (GO) solution. In addition, it can be a novel and potential material for application on the separation of water vapor from gaseous steam or larger alkali ions from aqueous solution. GOP could be used as electricity and thermal storage materials. The preparation of GO commonly uses high purity natural or artificial graphite. It is difficult to prepare GOP from artificial graphite powder due to the cost of $1,450 US/ton. In this study, we tried to prepare GOPs from homemade graphene sheets containing carbon materials (GSCCMs) and evaluate the thermal properties of GSCCM derived GOPs. Results show that GSCCM derived GOPs have a higher phase transition temperature, and the average mesophase phase change enthalpy is 9.41 J/g, which is 2.87 times higher than graphite derived GOP. Therefore, to prepare GOP from GSCCMs could highly reduce the cost.

  10. Comparison between remote sensing and a dynamic vegetation model for estimating terrestrial primary production of Africa.

    Science.gov (United States)

    Ardö, Jonas

    2015-12-01

    Africa is an important part of the global carbon cycle. It is also a continent facing potential problems due to increasing resource demand in combination with climate change-induced changes in resource supply. Quantifying the pools and fluxes constituting the terrestrial African carbon cycle is a challenge, because of uncertainties in meteorological driver data, lack of validation data, and potentially uncertain representation of important processes in major ecosystems. In this paper, terrestrial primary production estimates derived from remote sensing and a dynamic vegetation model are compared and quantified for major African land cover types. Continental gross primary production estimates derived from remote sensing were higher than corresponding estimates derived from a dynamic vegetation model. However, estimates of continental net primary production from remote sensing were lower than corresponding estimates from the dynamic vegetation model. Variation was found among land cover classes, and the largest differences in gross primary production were found in the evergreen broadleaf forest. Average carbon use efficiency (NPP/GPP) was 0.58 for the vegetation model and 0.46 for the remote sensing method. Validation versus in situ data of aboveground net primary production revealed significant positive relationships for both methods. A combination of the remote sensing method with the dynamic vegetation model did not strongly affect this relationship. Observed significant differences in estimated vegetation productivity may have several causes, including model design and temperature sensitivity. Differences in carbon use efficiency reflect underlying model assumptions. Integrating the realistic process representation of dynamic vegetation models with the high resolution observational strength of remote sensing may support realistic estimation of components of the carbon cycle and enhance resource monitoring, providing suitable validation data is available.

  11. Production of oxidatively stable fish oil enriched food emulsions

    DEFF Research Database (Denmark)

    Bruni Let, Mette

    Purpose: The objective of the project is to determine how a number of selected fish oil enriched foods can be protected against oxidation by the right choice of antioxidants, emulsifiers and optimal process conditions. Furthermore the influence of antioxidant addition to the fish oil it...... have many other health benefiting properties such as preventing heart diseases. Addition of fish oils to foods is therefore of interest. The many double bonds in the fatty acids are however susceptible to oxidation. Collaboration partners: The project is a collaborative project between DFU-FF, Bio......-self on the effect of antioxidants added to the foods will also be investigated. Background: Fish oils are rich sources of the long-chain polyunsaturated fatty acids EPA and DHA of which DHA is a vital component of the phospholipids of human cellular membranes, especially those in the brain and retina. Fish oils...

  12. Twenty-million-year relationship between mammalian diversity and primary productivity

    Science.gov (United States)

    Fritz, Susanne A.; Eronen, Jussi T.; Schnitzler, Jan; Hof, Christian; Janis, Christine M.; Mulch, Andreas; Böhning-Gaese, Katrin; Graham, Catherine H.

    2016-01-01

    At global and regional scales, primary productivity strongly correlates with richness patterns of extant animals across space, suggesting that resource availability and climatic conditions drive patterns of diversity. However, the existence and consistency of such diversity–productivity relationships through geological history is unclear. Here we provide a comprehensive quantitative test of the diversity–productivity relationship for terrestrial large mammals through time across broad temporal and spatial scales. We combine >14,000 occurrences for 690 fossil genera through the Neogene (23–1.8 Mya) with regional estimates of primary productivity from fossil plant communities in North America and Europe. We show a significant positive diversity–productivity relationship through the 20-million-year record, providing evidence on unprecedented spatial and temporal scales that this relationship is a general pattern in the ecology and paleo-ecology of our planet. Further, we discover that genus richness today does not match the fossil relationship, suggesting that a combination of human impacts and Pleistocene climate variability has modified the 20-million-year ecological relationship by strongly reducing primary productivity and driving many mammalian species into decline or to extinction. PMID:27621451

  13. Inhibition of oxidant production in rat adjuvant arthritis with perostilbene

    Czech Academy of Sciences Publication Activity Database

    Perečko, T.; Drábiková, K.; Nosáľ, R.; Harmatha, Juraj; Bauerová, K.; Mihalová, D.; Jančinová, V.

    2010-01-01

    Roč. 3, č. 3 (2010), A73-A74 ISSN 1337-6853. [Toxcon 2010, Borderless Toxicology. 15th Interdisciplinary Toxicological Conference & Advanced Toxicological Course. 06.09.-10.09.2010, Stará Lesná - Hotel Academia] R&D Projects: GA ČR(CZ) GA203/07/1227 Institutional research plan: CEZ:AV0Z40550506 Keywords : stilbene type polyphenols * antiinflammatory * oxidative burst of neutrophils Subject RIV: CC - Organic Chemistry

  14. A Study on the Oxidative-dissolution Leaching of Fission Product Oxides in the carbonate solution

    International Nuclear Information System (INIS)

    Lee, Eil Hee; Kim, Kwang Wook; Lim, Jae Gwan; Chung, Dong Yong; Yang, Han Beom; Joe, Kih Soo; Seo, Heui Seung; Kim, Yeon Hwa; Lee, Se Yoon

    2009-07-01

    This study was carried out to investigate the characteristics of an oxidativedissolution leaching of FP co-dissolved with U in a carbonate solution of Na 2 CO 3 - H 2 O 2 and (NH 4 ) 2 CO 3 -H 2 O 2 , respectively. Simulated FP-oxides which contained 12 components have been added to the solution to examine their oxidative dissolution characteristics. It was found that H 2 O 2 was an effective oxidant to minimize the dissolution of FP in a carbonate solution. In 0.5M Na 2 CO 3 -0.5M H 2 O 2 and 0.5M (NH 4 ) 2 CO 3 -0.5M H 2 O 2 solution, some elements such as Re, Te, Cs and Mo seem to be dissolved together with U. It is revealed that dissolution rates of Re, Te and Cs are high (completely dissolved within 10∼20 minutes) due to their high solubility in Na 2 CO 3 and (NH 4 ) 2 CO 3 solution regardless of the addition of H 2 O 2 , and independent of the concentrations of Na 2 CO 3 and H 2 O 2 . However, Mo was slowly dissolved by an oxidative dissolution with H 2 O 2 . It is found that the most important factor for the oxidative dissolution of FP is the pH of the solution and an effective oxidative dissolution is achieved at a pH between 10∼12 for Na 2 CO 3 and a pH between 9∼10 for (NH 4 ) 2 CO 3 , respectively, in order to minimize the dissolution of FP

  15. Shrubland primary production and soil respiration diverge along European climate gradient

    DEFF Research Database (Denmark)

    Reinsch, Sabine; Koller, Eva; Sowerby, Alwyn

    2017-01-01

    uncertain. Here we show the responses of ecosystem C to 8-12 years of experimental drought and night-time warming across an aridity gradient spanning seven European shrublands using indices of C assimilation (aboveground net primary production: aNPP) and soil C efflux (soil respiration: Rs). The changes...

  16. Joint control of terrestrial gross primary productivity by plant phenology and physiology

    DEFF Research Database (Denmark)

    Xia, Jianyang; Niu, Shuli; Ciais, Philippe

    2015-01-01

    Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate–carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of b...

  17. Effects of precipitation changes on aboveground net primary production and soil respiration in a switchgrass field

    Science.gov (United States)

    This study attempted to test whether switchgrass aboveground net primary production (ANPP) responds to precipitation (PPT) changes in a double asymmetry pattern as framed by Knapp et al. (2016), and whether it is held true for other ecosystem processes such as soil respiration (SR). Data were colle...

  18. Studies on the primary productivity of a polluted mangrove pond in ...

    African Journals Online (AJOL)

    The primary productivity of a polluted mangrove pond in Lagos was investigated for six months (October 2010-March 2011) using the chlorophyll-a method. Air and water temperatures were high (≥21°C) while transparency was lower than 11.5 cm at the mangrove pond. Total suspended solids were ≥2.0 mg/L while total ...

  19. Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

    KAUST Repository

    Gasol, Josep M.; Cardelú s, Clara; Moran, Xose Anxelu G.; Balagué , Vanessa; Forn, Irene; Marrasé , Cè lia; Massana, Ramon; Pedró s-Alió , Carlos; Sala, M. Montserrat; Simó , Rafel; Vaqué , Dolors; Estrada, Marta

    2016-01-01

    We carried out monthly photosynthesis-irradiance (P-E) experiments with the 14C-method for 12 years (2003–2014) to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a

  20. Estimating climate change effects on net primary production of rangelands in the United States

    Science.gov (United States)

    Matthew C. Reeves; Adam L. Moreno; Karen E. Bagne; Steven W. Running

    2014-01-01

    The potential effects of climate change on net primary productivity (NPP) of U.S. rangelands were evaluated using estimated climate regimes from the A1B, A2 and B2 global change scenarios imposed on the biogeochemical cycling model, Biome-BGC from 2001 to 2100. Temperature, precipitation, vapor pressure deficit, day length, solar radiation, CO2 enrichment and nitrogen...

  1. Evaluation of MODIS gross primary productivity for Africa using eddy covariance data

    CSIR Research Space (South Africa)

    Sjöström, M

    2013-04-01

    Full Text Available MOD17A2 provides operational gross primary production (GPP) data globally at 1 km spatial resolution and 8-day temporal resolution. MOD17A2 estimates GPP according to the light use efficiency (LUE) concept assuming a fixed maximum rate of carbon...

  2. Variance-based sensitivity analysis of BIOME-BGC for gross and net primary production

    NARCIS (Netherlands)

    Raj, R.; Hamm, N.A.S.; van der Tol, C.; Stein, A.

    2014-01-01

    Parameterization and calibration of a process-based simulator (PBS) is a major challenge when simulating gross and net primary production (GPP and NPP). The large number of parameters makes the calibration computationally expensive and is complicated by the dependence of several parameters on other

  3. Creating a regional MODIS satellite-driven net primary production dataset for european forests

    NARCIS (Netherlands)

    Neumann, Mathias; Moreno, Adam; Thurnher, Christopher; Mues, Volker; Härkönen, Sanna; Mura, Matteo; Bouriaud, Olivier; Lang, Mait; Cardellini, Giuseppe; Thivolle-Cazat, Alain; Bronisz, Karol; Merganic, Jan; Alberdi, Iciar; Astrup, Rasmus; Mohren, Frits; Zhao, Maosheng; Hasenauer, Hubert

    2016-01-01

    Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm

  4. Joint control of terrestrial gross primary productivity by plant phenology and physiology

    NARCIS (Netherlands)

    Xia, J.; Niu, S.; Ciais, P.; Janssens, I.A.; Chen, J.; Ammann, C.; Arain, A.; Blanken, P.D.; Cescatti, A.; Moors, E.J.

    2015-01-01

    Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate–carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of

  5. Cell specific primary production of autotrophic and mixotrophic phytoplankton in acidified lakes of the Bohemian Forest

    Czech Academy of Sciences Publication Activity Database

    Znachor, Petr; Nedoma, Jiří

    2004-01-01

    Roč. 112, - (2004), s. 141-155 ISSN 0342-1120 R&D Projects: GA ČR(CZ) GA206/98/0727; GA ČR(CZ) GA206/97/0072 Keywords : autoradiography * mixotrophy * primary production Subject RIV: EH - Ecology, Behaviour

  6. Seasonal primary production in different sectors of the EEZ of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarupria, J.S.; Bhargava, R.M.S.

    The seasonal and regional variations in the primary production, based on the data collected at 562 stations over the period from 1962 to 1988, are presented. The entire Indian Exclusive Economic Zone (EEZ), measuring 2.01 million km super(2...

  7. UV radiation and natural fluorescence linked primary production in Antarctic waters

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; KrishnaKumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

    Primary productivity and chlorophyll values have been measured using an underwater profiling radiometer for the first time in the waters around Indian Antarctic Station (70°46'S & 11°44'E) in the summer of 1994. The profiles include natural...

  8. Increased light-use efficiency sustains net primary productivity of shaded coffee plants in agroforestry system.

    Science.gov (United States)

    Charbonnier, Fabien; Roupsard, Olivier; le Maire, Guerric; Guillemot, Joannès; Casanoves, Fernando; Lacointe, André; Vaast, Philippe; Allinne, Clémentine; Audebert, Louise; Cambou, Aurélie; Clément-Vidal, Anne; Defrenet, Elsa; Duursma, Remko A; Jarri, Laura; Jourdan, Christophe; Khac, Emmanuelle; Leandro, Patricia; Medlyn, Belinda E; Saint-André, Laurent; Thaler, Philippe; Van Den Meersche, Karel; Barquero Aguilar, Alejandra; Lehner, Peter; Dreyer, Erwin

    2017-08-01

    In agroforestry systems, shade trees strongly affect the physiology of the undergrown crop. However, a major paradigm is that the reduction in absorbed photosynthetically active radiation is, to a certain extent, compensated by an increase in light-use efficiency, thereby reducing the difference in net primary productivity between shaded and non-shaded plants. Due to the large spatial heterogeneity in agroforestry systems and the lack of appropriate tools, the combined effects of such variables have seldom been analysed, even though they may help understand physiological processes underlying yield dynamics. In this study, we monitored net primary productivity, during two years, on scales ranging from individual coffee plants to the entire plot. Absorbed radiation was mapped with a 3D model (MAESPA). Light-use efficiency and net assimilation rate were derived for each coffee plant individually. We found that although irradiance was reduced by 60% below crowns of shade trees, coffee light-use efficiency increased by 50%, leaving net primary productivity fairly stable across all shade levels. Variability of aboveground net primary productivity of coffee plants was caused primarily by the age of the plants and by intraspecific competition among them (drivers usually overlooked in the agroforestry literature) rather than by the presence of shade trees. © 2017 John Wiley & Sons Ltd.

  9. Primary production, nutrients, and size spectra of suspended particles in the southern North Sea

    NARCIS (Netherlands)

    Gieskes, W.W.C.

    1972-01-01

    The effect of nutrient enrichment from the Rhine on some major characteristics of the phytoplankton ecosystem of Dutch coastal waters was studied with 14C, liquid scintillation and Coulter Counter techniques. The magnitude of primary production in the most eutrophic waters closest to

  10. Improved estimates of net primary productivity from MODIS satellite data at regional and local scales

    Science.gov (United States)

    Yude Pan; Richard Birdsey; John Hom; Kevin McCullough; Kenneth Clark

    2006-01-01

    We compared estimates of net primary production (NPP) from the MODIS satellite with estimates from a forest ecosystem process model (PnET-CN) and forest inventory and analysis (FIA) data for forest types of the mid-Atlantic region of the United States. The regional means were similar for the three methods and for the dominant oak? hickory forests in the region. However...

  11. Modeling gross primary production of an evergreen needleleaf forest using MODIS and climate data

    Science.gov (United States)

    Xiangming Xiao; Qingyuan Zhang; David Hollinger; John Aber; Berrien, III Moore

    2005-01-01

    Forest canopies are composed of photosynthetically active vegetation (PAV, chloroplasts) and nonphotosynthetic vegetation (NPV, e.g., cell wall, vein, branch). The fraction of photosynthetically active radiation (PAR) absorbed by the canopy (FAPAR) should be partitioned into FAPARPAV and FAPARNPV. Gross primary production (...

  12. Planktonic primary production evaluation by means of the 14C method with liquid scintillation counting

    International Nuclear Information System (INIS)

    Frangopol, T.P.; Bologa, S.A.

    1979-05-01

    Preliminary results on the planktonic primary production obtained for the first time with the 14 C method off the Romanian Black Sea coast (1977, 1978) and in the Sinoe, Mamaia and Bicaz lakes (1978) are presented, along with a review of this method with special reference to liquid scintillation counting. 140 Refs. (author)

  13. Evaluation of MODIS gross primary productivity for Africa using eddy covariance data

    NARCIS (Netherlands)

    Sjostrom, M.; Zhao, M.; Archibald, S.; Veenendaal, E.M.

    2013-01-01

    MOD17A2 provides operational gross primary production (GPP) data globally at 1 km spatial resolution and 8-day temporal resolution. MOD17A2 estimates GPP according to the light use efficiency (LUE) concept assuming a fixed maximum rate of carbon assimilation per unit photosynthetically active

  14. Estimating primary production from oxygen time series: A novel approach in the frequency domain

    NARCIS (Netherlands)

    Cox, T.J.S.; Maris, T.; Soetaert, K.; Kromkamp, J.C.; Meire, P.; Meysman, F.J.R.

    2015-01-01

    Based on an analysis in the frequency domain of the governing equation of oxygen dynamics in aquatic systems, we derive a new method for estimating gross primary production (GPP) from oxygen time series. The central result of this article is a relation between time averaged GPP and the amplitude of

  15. Vegetation-specific model parameters are not required for estimating gross primary production

    Czech Academy of Sciences Publication Activity Database

    Yuan, W.; Cai, W.; Liu, S.; Dong, W.; Chen, J.; Altaf Arain, M.; Blanken, P. D.; Cescatti, A.; Wohlfahrt, G.; Georgiadis, T.; Genesio, L.; Gianelle, D.; Grelle, A.; Kiely, G.; Knohl, A.; Liu, D.; Marek, Michal V.; Merbold, L.; Montagnani, L.; Panferov, O.; Peltoniemi, M.; Rambal, S.; Raschi, A.; Varlagin, A.; Xia, J.

    2014-01-01

    Roč. 292, NOV 24 2014 (2014), s. 1-10 ISSN 0304-3800 Institutional support: RVO:67179843 Keywords : light use efficiency * gross primary production * model parameters Subject RIV: EH - Ecology, Behaviour Impact factor: 2.321, year: 2014

  16. Relationships between net primary productivity and forest stand age in U.S. forests

    Science.gov (United States)

    Liming He; Jing M. Chen; Yude Pan; Richard Birdsey; Jens. Kattge

    2012-01-01

    Net primary productivity (NPP) is a key flux in the terrestrial ecosystem carbon balance, as it summarizes the autotrophic input into the system. Forest NPP varies predictably with stand age, and quantitative information on the NPP-age relationship for different regions and forest types is therefore fundamentally important for forest carbon cycle modeling. We used four...

  17. Metformin protects primary rat hepatocytes against oxidative stress-induced apoptosis

    NARCIS (Netherlands)

    Conde de la Rosa, Laura; Vrenken, Titia E; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han

    The majority of chronic liver diseases are accompanied by oxidative stress, which induces apoptosis in hepatocytes and liver injury. Recent studies suggest that oxidative stress and insulin resistance are important in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and the

  18. Transport of radioactive corrosion products in primary system of sodium-cooled fast breeder reactor 'MONJU'

    International Nuclear Information System (INIS)

    Matuo, Youichirou; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya

    2011-01-01

    Radioactive corrosion products (CP) are primary cause of personal radiation exposure during maintenance work at FBR plants with no breached fuel. The PSYCHE code has been developed based on the Solution-Precipitation model for analysis of CP transfer behavior. We predicted and analyzed the CP solution and precipitation behavior of MONJU to evaluate the applicability of the PSYCHE code to MONJU, using the parameters verified in the calculations for JOYO. From the calculation result pertaining to the MONJU system, distribution of 54 Mn deposited in the primary cooling system over 20 years of operation is predicted to be approximately 7 times larger than that of 60 Co. In particular, predictions show a notable tendency for 54 Mn precipitation to be distributed in the primary pump and cold-leg. The calculated distribution of 54 Mn and 60 Co in the primary cooling system of MONJU agreed with tendencies of measured distribution of JOYO. (author)

  19. An investigation of oxidation products and SOA yields from OH + pesticide reactions

    Science.gov (United States)

    Murschell, T.; Friedman, B.; Link, M.; Farmer, D.

    2016-12-01

    Pesticides are used globally in agricultural and residential areas. After application and/or volatilization from a surface, these compounds can be transported over long distances in the atmosphere. However, their chemical fate, including oxidation and gas-particle partitioning in the atmosphere, is not well understood. We present gas and particle measurements of oxidation products from pesticide + OH reactions using a dynamic solution injection system coupled to an Oxidative Flow Reactor. Products were detected with a High Resolution Time of Flight Iodide Chemical Mass Spectrometer (HR-ToF-CIMS) and a Size Mobility Particle Scanner (SMPS). The OFR allows pesticides to react with variable OH radical exposures, ranging from the equivalent of one day to a full week of atmospheric oxidative aging. In this work, we explore pesticide oxidation products from reaction with OH and ozone, and compare those products to photolysis reactions. Pesticides of similar chemical structures were explored, including acetochlor / metolachlor and permethrin / cypermethrin, to explore mechanistic differences. We present chemical parameters including average product oxidation state, average oxygen to carbon ratio, and potential secondary organic aerosol formation for each of these compounds.

  20. Molecular basis for arsenic-Induced alteration in nitric oxide production and oxidative stress: implication of endothelial dysfunction

    International Nuclear Information System (INIS)

    Kumagai, Yoshito; Pi Jingbo

    2004-01-01

    Accumulated epidemiological studies have suggested that prolonged exposure of humans to arsenic in drinking water is associated with vascular diseases. The exact mechanism of how this occurs currently unknown. Nitric oxide (NO), formed by endothelial NO synthase (eNOS), plays a crucial role in the vascular system. Decreased availability of biologically active NO in the endothelium is implicated in the pathophysiology of several vascular diseases and inhibition of eNOS by arsenic is one of the proposed mechanism s for arsenic-induced vascular diseases. In addition, during exposure to arsenic, overproduction of reactive oxygen species (ROS) can occur, resulting in oxidative stress, which is another major risk factor for vascular dysfunction. The molecular basis for decreased NO levels and increased oxidative stress during arsenic exposure is poorly understood. In this article, evidence for arsenic-mediated alteration in NO production and oxidative stress is reviewed. The results of a cross-sectional study in an endemic area of chronic arsenic poisoning and experimental animal studies to elucidate a potential mechanism for the impairment of NO formation and oxidative stress caused by prolonged exposure to arsenate in the drinking water are also reviewed

  1. Korean red ginseng and its primary ginsenosides inhibit ethanol-induced oxidative injury by suppression of the MAPK pathway in TIB-73 cells.

    Science.gov (United States)

    Park, Hye-Min; Kim, Shang-Jin; Mun, A-Reum; Go, Hyeon-Kyu; Kim, Gi-Beum; Kim, Sung-Zoo; Jang, Seon-Il; Lee, Sei-Jin; Kim, Jin-Shang; Kang, Hyung-Sub

    2012-06-14

    Panax ginseng (P. ginseng) is one of the most widely used medicinal plants due to its wide spectrum of medicinal effects. Among the currently available Panax ginseng products, Korea red ginseng (KRG) has been shown to exhibit a variety of antioxidative and hepatoprotective action. Our aim was to investigate the effects of KRG and its primary ginsenosides (Rg3 and Rh2) on EtOH-induced injury to mouse hepatocytes (TIB-73). We investigated the effects of KRG and its primary ginsenoside on EtOH-induced injury to TIB-73 cells and evaluated MAPKs signals as a possible mechanism of action. Hepatocytic injury was evaluated by biochemical assays as cell viability, lactate dehydrogenase (LDH), aspartate aminotransferase (AST), ROS and mitochondria membrane potential (MMP) level in TIB-73 cells. The levels of MAPK activation were analyzed by Western blots. The results showed that exposure of EtOH to TIB-73 cells led to cell death and membrane damage, accompanied by a decrease in cell viability, MMP, and Mg(2+) concentrations, but an increase in LDH, AST, ROS and MAPK activation. KRG and its primary ginsenosides reduced EtOH-induced generation of ROS and the activation of ERK and JNK, and increased Mg(2+) concentrations. These results suggest that KRG and its primary ginsenosides inhibit EtOH-induced oxidative injury by suppression of the MAPK pathway in TIB-73 cells. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Primary production in a tropical large lake: The role of phytoplankton composition

    Energy Technology Data Exchange (ETDEWEB)

    Darchambeau, F., E-mail: francois.darchambeau@ulg.ac.be [Chemical Oceanography Unit, University of Liège, Liège (Belgium); Sarmento, H., E-mail: hugo.sarmento@gmail.com [Department of Hydrobiology, Federal University of São Carlos, 13565-905 São Carlos, São Paulo (Brazil); Descy, J.-P., E-mail: jean-pierre.descy@unamur.be [Research Unit in Environmental and Evolutionary Biology, University of Namur, Namur (Belgium)

    2014-03-01

    Phytoplankton biomass and primary production in tropical large lakes vary at different time scales, from seasons to centuries. We provide a dataset made of 7 consecutive years of phytoplankton biomass and production in Lake Kivu (Eastern Africa). From 2002 to 2008, bi-weekly samplings were performed in a pelagic site in order to quantify phytoplankton composition and biomass, using marker pigments determined by HPLC. Primary production rates were estimated by 96 in situ {sup 14}C incubations. A principal component analysis showed that the main environmental gradient was linked to a seasonal variation of the phytoplankton assemblage, with a clear separation between diatoms during the dry season and cyanobacteria during the rainy season. A rather wide range of the maximum specific photosynthetic rate (P{sub Bm}) was found, ranging between 1.15 and 7.21 g carbon g{sup −1} chlorophyll a h{sup −1}, and was best predicted by a regression model using phytoplankton composition as an explanatory variable. The irradiance at the onset of light saturation (I{sub k}) ranged between 91 and 752 μE m{sup −2} s{sup −1} and was linearly correlated with the mean irradiance in the mixed layer. The inter-annual variability of phytoplankton biomass and production was high, ranging from 53 to 100 mg chlorophyll a m{sup −2} (annual mean) and from 143 to 278 g carbon m{sup −2} y{sup −1}, respectively. The degree of seasonal mixing determined annual production, demonstrating the sensitivity of tropical lakes to climate variability. A review of primary production of other African great lakes allows situating Lake Kivu productivity in the same range as that of lakes Tanganyika and Malawi, even if mean phytoplankton biomass was higher in Lake Kivu. - Highlights: • We provide a 7-year dataset of primary production in a tropical great lake. • Specific photosynthetic rate was determined by community composition. • Annual primary production varied between 143 and 278 mg C m

  3. Primary production in a tropical large lake: The role of phytoplankton composition

    International Nuclear Information System (INIS)

    Darchambeau, F.; Sarmento, H.; Descy, J.-P.

    2014-01-01

    Phytoplankton biomass and primary production in tropical large lakes vary at different time scales, from seasons to centuries. We provide a dataset made of 7 consecutive years of phytoplankton biomass and production in Lake Kivu (Eastern Africa). From 2002 to 2008, bi-weekly samplings were performed in a pelagic site in order to quantify phytoplankton composition and biomass, using marker pigments determined by HPLC. Primary production rates were estimated by 96 in situ 14 C incubations. A principal component analysis showed that the main environmental gradient was linked to a seasonal variation of the phytoplankton assemblage, with a clear separation between diatoms during the dry season and cyanobacteria during the rainy season. A rather wide range of the maximum specific photosynthetic rate (P Bm ) was found, ranging between 1.15 and 7.21 g carbon g −1 chlorophyll a h −1 , and was best predicted by a regression model using phytoplankton composition as an explanatory variable. The irradiance at the onset of light saturation (I k ) ranged between 91 and 752 μE m −2 s −1 and was linearly correlated with the mean irradiance in the mixed layer. The inter-annual variability of phytoplankton biomass and production was high, ranging from 53 to 100 mg chlorophyll a m −2 (annual mean) and from 143 to 278 g carbon m −2 y −1 , respectively. The degree of seasonal mixing determined annual production, demonstrating the sensitivity of tropical lakes to climate variability. A review of primary production of other African great lakes allows situating Lake Kivu productivity in the same range as that of lakes Tanganyika and Malawi, even if mean phytoplankton biomass was higher in Lake Kivu. - Highlights: • We provide a 7-year dataset of primary production in a tropical great lake. • Specific photosynthetic rate was determined by community composition. • Annual primary production varied between 143 and 278 mg C m −2 y −1 . • Pelagic production was highly

  4. Circulating nitric oxide products do not solely reflect nitric oxide release in cirrhosis and portal hypertension

    DEFF Research Database (Denmark)

    Afzelius, Pia; Bazeghi, Nassim; Bie, Peter

    2011-01-01

    Patients with cirrhosis often develop a systemic vasodilatation and a hyperdynamic circulation with activation of vasoconstrictor systems such as the renin-angiotensin-aldosterone system (RAAS), and vasopressin. Increased nitric oxide (NO) synthesis has been implicated in the development of this ...

  5. Effect of influenza vaccination on oxidative stress products in breath.

    Science.gov (United States)

    Phillips, Michael; Cataneo, Renee N; Chaturvedi, Anirudh; Danaher, Patrick J; Devadiga, Anantrai; Legendre, David A; Nail, Kim L; Schmitt, Peter; Wai, James

    2010-06-01

    Viral infections cause increased oxidative stress, so a breath test for oxidative stress biomarkers (alkanes and alkane derivatives) might provide a new tool for early diagnosis. We studied 33 normal healthy human subjects receiving scheduled treatment with live attenuated influenza vaccine (LAIV). Each subject was his or her own control, since they were studied on day 0 prior to vaccination, and then on days 2, 7 and 14 following vaccination. Breath volatile organic compounds (VOCs) were collected with a breath collection apparatus, then analyzed by automated thermal desorption with gas chromatography and mass spectroscopy. A Monte Carlo simulation technique identified non-random VOC biomarkers of infection based on their C-statistic values (area under curve of receiver operating characteristic). Treatment with LAIV was followed by non-random changes in the abundance of breath VOCs. 2, 8-Dimethyl-undecane and other alkane derivatives were observed on all days. Conservative multivariate models identified vaccinated subjects on day 2 (C-statistic = 0.82, sensitivity = 63.6% and specificity = 88.5%); day 7 (C-statistic = 0.94, sensitivity = 88.5% and specificity = 92.3%); and day 14 (C-statistic = 0.95, sensitivity = 92.3% and specificity = 92.3%). The altered breath VOCs were not detected in live attenuated influenza vaccine, excluding artifactual contamination. LAIV vaccination in healthy humans elicited a prompt and sustained increase in breath biomarkers of oxidative stress. A breath test for these VOCs could potentially identify humans who are acutely infected with influenza, but who have not yet developed clinical symptoms or signs of disease.

  6. Production of the oxidation-resistant polypropylene track membranes

    International Nuclear Information System (INIS)

    Kravets, L.I.; Dmitriev, S.N.; Apel, P.Y.

    1999-01-01

    This paper describes results of the method of manufacturing the polypropylene track membranes produced by physicochemical treatment under irradiation of accelerated heavy ions of polymer films. The developed method allows to produce membranes 0.1 - 0.2 μm in diameter and more with an improved structural and physicochemical properties. Poly-propylene track membranes of a novel sample are characterized by high homogeneity of pore sizes in magnitude, considerable mechanical strength, advanced thermal stability and resistance to oxidation in aggressive media. It opens new fields for their usage

  7. Production of zinc oxide nanowires power with precisely defined morphology

    Czech Academy of Sciences Publication Activity Database

    Mičová, J.; Remeš, Zdeněk; Chang, Yu-Ying

    2017-01-01

    Roč. 68, č. 7 (2017), s. 66-69 ISSN 1335-3632 R&D Projects: GA ČR GC16-10429J Grant - others:AV ČR(CZ) KONNECT-007 Program:Bilaterální spolupráce Institutional support: RVO:68378271 Keywords : zinc oxide nanowires * hydrothermal growth method * scanning electron microscopy (SEM) Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.483, year: 2016

  8. Chemical aspects of fission product transport in the primary circuit of a light water reactor

    International Nuclear Information System (INIS)

    Bowsher, B.R.; Dickinson, S.; Nichols, A.L.; Ogden, J.S.; Potter, P.E.

    1985-01-01

    The transport and fission products in the primary circuit of a light water reactor are of fundamental importance in assessing the consequences of severe accidents. Recent experimental studies have concentrated upon the behaviour of simulant fission product species such as caesium iodide, caesium hydroxide and tellurium, in terms of their vapour deposition characteristics onto metals representative of primary circuit materials. An induction furnace has been used to generate high-density/structural materials aerosols for subsequent analysis, and similar equipment has been incorporated into a glove-box to study lightly-irradiated UO/sub 2/ clad in Zircaloy. Analytical techniques are being developed to assist in the identification of fission product chemical species released from the fuel at temperatures from 1000 to 2500 0 C. Matrix isolation-infrared spectroscopy has been used to identify species in the vapour phase, and specific data using this technique are reported

  9. Chemical aspects of fission product transport in the primary circuit of a light water reactor

    International Nuclear Information System (INIS)

    Bowsher, B.R.; Dickinson, S.; Nichols, A.L.; Ogden, J.S.; Potter, P.E.

    1985-01-01

    The transport and deposition of fission products in the primary circuit of a light water reactor are of fundamental importance in assessing the consequences of severe accidents. Recent experimental studies have concentrated upon the behavior of simulant fission product species such as cesium iodide, cesium hydroxide and tellurium, in terms of their vapor deposition characteristics onto metals representative of primary circuit materials. An induction furnace has been used to generate high density/structural materials aerosols for subsequent analysis, and similar equipment has been incorporated into a glove-box to study lightly-irradiated UO 2 clad in Zircaloy. Analytical techniques are being developed to assist in the identification of fission product chemical species released from the fuel at temperatures from 1000 to 2500 0 C. Matrix isolation-infrared spectroscopy has been used to identify species in the vapor phase, and specific data using this technique are reported

  10. Modelling the behaviour of corrosion products in the primary heat transfer circuits of pressurised water reactors

    International Nuclear Information System (INIS)

    Rodliffe, R.S.; Polley, M.V.; Thornton, E.W.

    1985-05-01

    The redistribution of corrosion products from the primary circuit surfaces of a water reactor can result in increased flow resistance, poorer heat transfer performance, fuel failure and radioactive contamination of circuit surfaces. The environment is generally sufficiently well controlled to ensure that the first three effects are not limiting. The last effect is of particular importance since radioactive corrosion products are major contributors to shutdown fields and since it is necessary to ensure that the radiation exposure of personnel is as low as reasonably achievable. This review focusses attention on the principles which must form the basis for any mechanistic model describing the formation, transport and deposition of radioactive corrosion products. It is relevant to all water reactors in which the primary heat transfer medium is predominantly single-phase water and in which steam is generated in a secondary circuit, i.e. including CANDU pressurised heavy water reactors, Sovient VVERs, etc. (author)

  11. TiO2 assisted photo-oxidative pretreatment of wheat straw for biogas production

    DEFF Research Database (Denmark)

    Awais, Muhammad; Alvarado-Morales, Merlin; Tsapekos, Panagiotis

    Photo-catalytic oxidation is an advanced oxidation process in which a catalyst is used to absorb light energy and oxidize the target substrates such as organic polymers. A number of metal oxides and metal ions can efficiently increase substrate’s depolymerisation during the process of photo...... to be markedly higher in the pretreated samples that were exposed for 180min with 1.5 wt% and 2 wt% of TiO2 compared to the untreated wheat straw. Moreover, it was concluded that the products of lignin oxidation and also, the presence of TiO2 did not inhibit the AD process. Finally, UV treatment or TiO2 alone......-catalytic oxidation. Titanium oxide (TiO2) is a photo-catalyst that in its rutile and anatase forms presents the property to enhance the photo-oxidation of lignin-containing substrates. Due to lignin is one of the major obstacles in methane production from lignocellulosic biomass, its destruction is a necessary step...

  12. Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection

    DEFF Research Database (Denmark)

    Kolpen, Mette; Kühl, Michael; Bjarnsholt, Thomas

    2014-01-01

    local anoxia by consuming the majority of O2 for production of reactive oxygen species (ROS). We hypothesized that P. aeruginosa acquires energy for growth in anaerobic endobronchial mucus by denitrification, which can be demonstrated by production of nitrous oxide (N2O), an intermediate...

  13. Nitrous oxide production, its source and distribution in urine patches on grassland on peat soil.

    NARCIS (Netherlands)

    Koops, J.G.; Beusichem, van M.L.; Oenema, O.

    1997-01-01

    Urine patches are considered to be important sites for nitrous oxide (N2O) production through nitrification and denitrification due to their high concentration of nitrogen (N). The aim of the present study was to determine the microbial source and size of production of N2O in different zones of a

  14. The application of HTR type modular plants in refinieries and for aluminium oxide production

    International Nuclear Information System (INIS)

    Schad, M.; Clausen, E.; Funke, A.; Heng, R.; Poesche, W.; Simon, P.; Schwarz, T.; Feltes, W.; Hague, H.; Heidkamp, H.; Hesse, K.; Kohtz, N.; Mendte, K.; Ullrich, M.; Wild, W.; Zipper, E.

    1991-02-01

    The aim of the second study of coupling the HTR module to process plants consistsed in developing concepts for potential plants and analysing them again for their technical and economic feasibility. At each of the three process plants, heat is coupled in by a He/He intermediate heat exchanger. This principle of heat coupling was consistently aimed at - in order to keep the expensive nuclear part of plant coupling as small as possible, and - in order to avoid that primary helium can get into the process plants, just as vice versa process media into the HTRM-helium circuit. For refineries this principle is easy to comply with because of the low process temperatures of below 600deg C. For aluminium oxide production which conventionally requires a temperature of about 950deg C, calcination tests were made at lower process temperatures, and parallely the feed-in of heat to reach the highest process temperature through electric heating was studied. For petrochemistry, heat transfer during naptha cracking was closely analysed. (orig./GL) [de

  15. Nitrogen oxides in the combustion products of gas cookers

    Energy Technology Data Exchange (ETDEWEB)

    Benes, M.; Zahourek, J.

    1981-07-01

    The combustion of town gas and natural gas in two types of gas ranges manufactured in Czechoslovakia resulted in measurable amounts of NO/sub x/ in both the combustion products and the surrounding air. In all the cases tested, the amounts of NO/sub x/ given off exceeded levels permitted by current Czech standards. These results indicate that before the widespread use of any new gas ranges, their combustion products should be tested for NO/sub x/.

  16. Arginine de novo and nitric oxide production in disease states

    OpenAIRE

    Luiking, Yvette C.; Ten Have, Gabriella A. M.; Wolfe, Robert R.; Deutz, Nicolaas E. P.

    2012-01-01

    Arginine is derived from dietary protein intake, body protein breakdown, or endogenous de novo arginine production. The latter may be linked to the availability of citrulline, which is the immediate precursor of arginine and limiting factor for de novo arginine production. Arginine metabolism is highly compartmentalized due to the expression of the enzymes involved in arginine metabolism in various organs. A small fraction of arginine enters the NO synthase (NOS) pathway. Tetrahydrobiopterin ...

  17. Hydrogen production by ethanol partial oxidation over nano-iron oxide catalysts produced by chemical vapour synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Wael Ahmed Abou Taleb Sayed

    2011-01-13

    This work presents the experimental results of the synthesis of unsupported and supported SiC iron oxide nanoparticles and their catalytic activity towards ethanol partial oxidation. For comparison, further unsupported iron oxide phases were investigated towards the ethanol partial oxidation. These {gamma}-Fe{sub 2}O{sub 3} and {alpha}/{gamma}-Fe{sub 2}O{sub 3} phase catalysts were prepared by the CVS method using Fe(CO){sub 5} as precursor, supplied by another author. The {alpha}-Fe{sub 2}O{sub 3} and SiC nanoparticles were prepared by the CVS method using a home made hot wall reactor technique at atmospheric pressure. Ferrocene and tetramethylsilane were used as precursor for the production process. Process parameters of precursor evaporation temperature, precursor concentration, gas mixture velocity and gas mixture dilution were investigated and optimised to produce particle sizes in a range of 10 nm. For Fe{sub 2}O{sub 3}/SiC catalyst series production, a new hot wall reactor setup was used. The particles were produced by simultaneous thermal decomposition of ferrocene and tetramethylsilane in one reactor from both sides. The production parameters of inlet tube distance inside the reactor, precursor evaporation temperature and carrier gas flow were investigated to produce a series of samples with different iron oxide content. The prepared catalysts composition, physical and chemical properties were characterized by XRD, EDX, SEM, BET surface area, FTIR, XPS and dynamic light scattering (DLS) techniques. The catalytic activity for the ethanol gas-phase oxidation was investigated in a temperature range from 260 C to 290 C. The product distributions obtained over all catalysts were analysed with mass spectrometry analysis tool. The activity of bulk Fe{sub 2}O{sub 3} and SiC nanoparticles was compared with prepared nano-iron oxide phase catalysts. The reaction parameters, such as reaction temperature and O{sub 2}/ethanol ratio were investigated. The catalysts

  18. Production of petroleum bitumen by oxidation of heavy oil residue with sulfur

    Science.gov (United States)

    Tileuberdi, Ye.; Akkazyn, Ye. A.; Ongarbayev, Ye. K.; Imanbayev, Ye. I.; Mansurov, Z. A.

    2018-03-01

    In this paper production of bitumen adding elemental sulfur at oxidation of oil residue are investigated. The objects of research were distilled residue of Karazhanbas crude oil and elemental sulfur. These oil residue characterized by a low output of easy fractions and the high content of tar-asphaltene substances, therefore is the most comprehensible feedstock for producing bitumen. The sulfur is one of the oil product collected in oil extraction regions. Oxidation process of hydrocarbons carried out at temperatures from 180 up to 210 °С without addition of sulfur and with the addition of sulfur (5-10 wt. %) for 4 hours. At 200 °С oxidation of hydrocarbons with 5, 7 and 10 wt.% sulfur within 3-4 h allows receiving paving bitumen on the mark BND 200/300, BND 130/200, BN 90/130 and BN 70/30. Physical and mechanical characteristics of oxidation products with the addition of 5-7 wt. % sulfur corresponds to grade of paving bitumen BND 40/60. At the given temperature oxidized for 2.5-3 h, addition of 10 wt. % sulfur gave the products of oxidation describing on parameters of construction grades of bitumen (BN 90/10).

  19. Mycoplasma hyopneumoniae-derived lipid-associated membrane proteins induce apoptosis in porcine alveolar macrophage via increasing nitric oxide production, oxidative stress, and caspase-3 activation.

    Science.gov (United States)

    Bai, Fangfang; Ni, Bo; Liu, Maojun; Feng, Zhixin; Xiong, Qiyan; Xiao, Shaobo; Shao, Guoqing

    2013-09-15

    Mycoplasma hyopneumoniae is the primary etiological agent of enzootic pneumonia in swine. Lipid-associated membrane proteins (LAMP) of mycoplasma are the main pathogenicity factors in mycoplasma diseases. In this study, we investigated the effects of M. hyopneumoniae LAMP on porcine alveolar macrophage (PAM) 3D4/21 cell line. Apoptotic features, such as chromatin condensation and apoptotic bodies, were observed in LAMP-treated PAM 3D4/21 cells. Moreover, LAMP significantly increased the number of TUNEL positive apoptotic cells in PAM 3D4/21 cells compared with the untreated control. In addition, flow cytometric analysis using dual staining with annexin-V-FITC and propidium iodide (PI) showed that LAMP of M. hyopneumoniae induced a time-dependent apoptosis in PAM 3D4/21 cells. Moreover, increased levels of superoxide anion production and activated caspase-3 in PAM 3D4/21 cells were observed after exposure to LAMP. Increased production of nitric oxide (NO) was also confirmed in the cell supernatants. Besides, apoptotic rates increase and caspase-3 activation were suppressed by NOS inhibitor or antioxidant. It is suggested that LAMP of M. hyopneumoniae induced apoptosis in porcine alveolar macrophage via NO production, superoxide anion production, and caspase-3 activation. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. submitter Elemental composition and clustering behaviour of α-pinene oxidation products for different oxidation conditions

    CERN Document Server

    Praplan, A P; Bianchi, F; Rissanen, M P; Ehn, M; Jokinen, T; Junninen, H; Adamov, A; Amorim, A; Dommen, J; Duplissy, J; Hakala, J; Hansel, A; Heinritzi, M; Kangasluoma, J; Kirkby, J; Krapf, M; Kürten, A; Lehtipalo, K; Riccobono, F; Rondo, L; Sarnela, N; Simon, M; Tomé, A; Tröstl, J; Winkler, P M; Williamson, C; Ye, P; Curtius, J; Baltensperger, U; Donahue, N M; Kulmala, M; Worsnop, D R

    2015-01-01

    This study presents the difference between oxidised organic compounds formed by α-pinene oxidation under various conditions in the CLOUD environmental chamber: (1) pure ozonolysis (in the presence of hydrogen as hydroxyl radical (OH) scavenger) and (2) OH oxidation (initiated by nitrous acid (HONO) photolysis by ultraviolet light) in the absence of ozone. We discuss results from three Atmospheric Pressure interface Time-of-Flight (APi-TOF) mass spectrometers measuring simultaneously the composition of naturally charged as well as neutral species (via chemical ionisation with nitrate). Natural chemical ionisation takes place in the CLOUD chamber and organic oxidised compounds form clusters with nitrate, bisulfate, bisulfate/sulfuric acid clusters, ammonium, and dimethylaminium, or get protonated. The results from this study show that this process is selective for various oxidised organic compounds with low molar mass and ions, so that in order to obtain a comprehensive picture of the elemental composition o...

  1. Nitric oxide, human diseases and the herbal products that affect the nitric oxide signalling pathway.

    Science.gov (United States)

    Achike, Francis I; Kwan, Chiu-Yin

    2003-09-01

    1. Nitric oxide (NO) is formed enzymatically from l-arginine in the presence of nitric oxide synthase (NOS). Nitric oxide is generated constitutively in endothelial cells via sheer stress and blood-borne substances. Nitric oxide is also generated constitutively in neuronal cells and serves as a neurotransmitter and neuromodulator in non-adrenergic, non-cholinergic nerve endings. Furthermore, NO can also be formed via enzyme induction in many tissues in the presence of cytokines. 2. The ubiquitous presence of NO in the living body suggests that NO plays an important role in the maintenance of health. Being a free radical with vasodilatory properties, NO exerts dual effects on tissues and cells in various biological systems. At low concentrations, NO can dilate the blood vessels and improve the circulation, but at high concentrations it can cause circulatory shock and induce cell death. Thus, diseases can arise in the presence of the extreme ends of the physiological concentrations of NO. 3. The NO signalling pathway has, in recent years, become a target for new drug development. The high level of flavonoids, catechins, tannins and other polyphenolic compounds present in vegetables, fruits, soy, tea and even red wine (from grapes) is believed to contribute to their beneficial health effects. Some of these compounds induce NO formation from the endothelial cells to improve circulation and some suppress the induction of inducible NOS in inflammation and infection. 4. Many botanical medicinal herbs and drugs derived from these herbs have been shown to have effects on the NO signalling pathway. For example, the saponins from ginseng, ginsenosides, have been shown to relax blood vessels (probably contributing to the antifatigue and blood pressure-lowering effects of ginseng) and corpus cavernosum (thus, for the treatment of men suffering from erectile dysfunction; however, the legendary aphrodisiac effect of ginseng may be an overstatement). Many plant extracts or

  2. In situ Investigation of Oxide Films on Zirconium Alloy in PWR Primary Water Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taeho; Choi, Kyoung Joon; Yoo, Seung Chang; Kim, Ji Hyun [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    Zirconium alloys are used as fuel cladding materials in nuclear power reactors, because these materials have a very low thermal neutron capture cross section as well as desirable mechanical properties. However, the Fukushima accident shows that the oxidation behavior of zirconium alloy is an important issue because the zirconium alloy functions as a shield of nuclear material (i.e., uranium, fission gas), and the degradation on zirconium cladding directly causes severe accident on nuclear power plant. Therefore, to ensure the safety of nuclear power reactors, the performance and sustainability of nuclear fuel should be understood. Currently, the water-metal interface is regarded as the rate-controlling site governing the rapid oxidation transition in high-burn-up fuels. Zirconium oxide is formed at the water-metal interface, and its structure and phase play an important role in determining its mechanical properties. In the early stage of the oxidation process, zirconium oxide with both tetragonal and monoclinic phases is formed. With an increase in the oxidation time to 150 h, the unstable tetragonal phase disappears and the monoclinic phase is dominant and possibly because of the stress relaxation according to previous and present results.

  3. Controlled nitric oxide production via O(1D) + N2O reactions for use in oxidation flow reactor studies

    Science.gov (United States)

    Lambe, Andrew; Massoli, Paola; Zhang, Xuan; Canagaratna, Manjula; Nowak, John; Daube, Conner; Yan, Chao; Nie, Wei; Onasch, Timothy; Jayne, John; Kolb, Charles; Davidovits, Paul; Worsnop, Douglas; Brune, William

    2017-06-01

    Oxidation flow reactors that use low-pressure mercury lamps to produce hydroxyl (OH) radicals are an emerging technique for studying the oxidative aging of organic aerosols. Here, ozone (O3) is photolyzed at 254 nm to produce O(1D) radicals, which react with water vapor to produce OH. However, the need to use parts-per-million levels of O3 hinders the ability of oxidation flow reactors to simulate NOx-dependent secondary organic aerosol (SOA) formation pathways. Simple addition of nitric oxide (NO) results in fast conversion of NOx (NO + NO2) to nitric acid (HNO3), making it impossible to sustain NOx at levels that are sufficient to compete with hydroperoxy (HO2) radicals as a sink for organic peroxy (RO2) radicals. We developed a new method that is well suited to the characterization of NOx-dependent SOA formation pathways in oxidation flow reactors. NO and NO2 are produced via the reaction O(1D) + N2O → 2NO, followed by the reaction NO + O3 → NO2 + O2. Laboratory measurements coupled with photochemical model simulations suggest that O(1D) + N2O reactions can be used to systematically vary the relative branching ratio of RO2 + NO reactions relative to RO2 + HO2 and/or RO2 + RO2 reactions over a range of conditions relevant to atmospheric SOA formation. We demonstrate proof of concept using high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) measurements with nitrate (NO3-) reagent ion to detect gas-phase oxidation products of isoprene and α-pinene previously observed in NOx-influenced environments and in laboratory chamber experiments.

  4. Denitrification: an important pathway for nitrous oxide production in tropical mangrove sediments (Goa, India).

    Science.gov (United States)

    Fernandes, Sheryl Oliveira; Bharathi, P A Loka; Bonin, Patricia C; Michotey, Valérie D

    2010-01-01

    Net nitrous oxide production and denitrification activity were measured in two mangrove ecosystems of Goa, India. The relatively pristine site Tuvem was compared to Divar, which is prone to high nutrient input. Stratified sampling at 2-cm intervals within the 0- to 10-cm depth range showed that N2O production at both the locations decreased with depth. Elevated denitrification activity at Divar resulted in maximum production of up to 1.95 nmol N2O-N g(-1) h(-1) at 2 to 4 cm, which was three times higher than at Tuvem. Detailed investigations to understand the major pathway contributing to N2O production performed at Tuvem showed that incomplete denitrification was responsible for up to 43 to 93% of N2O production. Nitrous oxide production rates closely correlated to nitrite concentration (n = 15; r = -0.47; p production. Nitrous oxide production through nitrification was below detection, affirming that denitrification is the major pathway responsible for production of the greenhouse gas. Net N2O production in these mangrove systems are comparatively higher than those reported from other natural estuarine sediments and therefore warrant mitigation measures.

  5. Relationships between primary production and irradiance in coral reef algal communities

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Shallow water algal turf communities are the major primary producers on coral reefs. High rates of primary production are maintained despite extremely high light intensities and exposure to ultraviolet wavelengths. The relationships between the light intensity and primary production in these assemblages are typical of algae adapted to a high light environment [low α (initial slope), high I/sub k/ (saturating light intensity), and high I/sub c/ (compensation point light intensity)]. Seasonal variations in algal standing crop due to herbivory and daylength result in some characteristic photoadaptive changes in α I/sub k/, and I/sub c/ and changes in Pnet/sub max/ rates (maximum net photosynthetic rate achieved at light saturation) on both a chlorophyll α and an areal basis. Exposure to UV wavelength results in significantly higher respiration rates but no changes in α, Pnet/sub max/, or I/sub k/, when compared with these parameters for the same algal communities incubated at the same light intensities without UV wavelengths. The apparent lack of photoinhibition in these algae allows calculation of the daily integrated production from the P vs. I parameters. This integrated production is highest in July (3.1 +/- 0.2 g C m -2 d -1 ) and is reduced by 30% from this maximum in December (2.1 +/- 0.1 g C m -2 d -1 )

  6. Assessing the impact of urbanization on regional net primary productivity in Jiangyin County, China.

    Science.gov (United States)

    Xu, C; Liu, M; An, S; Chen, J M; Yan, P

    2007-11-01

    Urbanization is one of the most important aspects of global change. The process of urbanization has a significant impact on the terrestrial ecosystem carbon cycle. The Yangtze Delta region has one of the highest rates of urbanization in China. In this study, carried out in Jiangyin County as a representative region within the Yangtze Delta, land use and land cover changes were estimated using Landsat TM and ETM+ imagery. With these satellite data and the BEPS process model (Boreal Ecosystem Productivity Simulator), the impacts of urbanization on regional net primary productivity (NPP) and annual net primary production were assessed for 1991 and 2002. Landsat-based land cover maps in 1991 and 2002 showed that urban development encroached large areas of cropland and forest. Expansion of residential areas and reduction of vegetated areas were the major forms of land transformation in Jiangyin County during this period. Mean NPP of the total area decreased from 818 to 699 gCm(-2)yr(-1) during the period of 1991 to 2002. NPP of cropland was only reduced by 2.7% while forest NPP was reduced by 9.3%. Regional annual primary production decreased from 808 GgC in 1991 to 691 GgC in 2002, a reduction of 14.5%. Land cover changes reduced regional NPP directly, and the increasing intensity and frequency of human-induced disturbance in the urbanized areas could be the main reason for the decrease in forest NPP.

  7. Efficiency of chlorophyll in gross primary productivity: A proof of concept and application in crops.

    Science.gov (United States)

    Gitelson, Anatoly A; Peng, Yi; Viña, Andrés; Arkebauer, Timothy; Schepers, James S

    2016-08-20

    One of the main factors affecting vegetation productivity is absorbed light, which is largely governed by chlorophyll. In this paper, we introduce the concept of chlorophyll efficiency, representing the amount of gross primary production per unit of canopy chlorophyll content (Chl) and incident PAR. We analyzed chlorophyll efficiency in two contrasting crops (soybean and maize). Given that they have different photosynthetic pathways (C3 vs. C4), leaf structures (dicot vs. monocot) and canopy architectures (a heliotrophic leaf angle distribution vs. a spherical leaf angle distribution), they cover a large spectrum of biophysical conditions. Our results show that chlorophyll efficiency in primary productivity is highly variable and responds to various physiological and phenological conditions, and water availability. Since Chl is accessible through non-destructive, remotely sensed techniques, the use of chlorophyll efficiency for modeling and monitoring plant optimization patterns is practical at different scales (e.g., leaf, canopy) and under widely-varying environmental conditions. Through this analysis, we directly related a functional characteristic, gross primary production with a structural characteristic, canopy chlorophyll content. Understanding the efficiency of the structural characteristic is of great interest as it allows explaining functional components of the plant system. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. Major activated corrosion products cobalt, silver and antimony in the primary coolant of PWR power plants

    International Nuclear Information System (INIS)

    Xu Mingxia

    2012-01-01

    The production of the major activated corrosion products such as cobalt, silver and antimony in the primary coolant of PWR power plants and the impacts on the increase of the dose rates caused by these corrosion products during the shutdown are described in the paper. Investigating the corrosion product behavior during the operation and shutdown periods aims at detecting the appearance of these radiological pollutants in the early time and searching relevant solutions that may enable eventually to decrease the dose rate. The solutions may include: Replacing critical material in the primary system's equipment and components, which contact with primary coolant circuit to possibly limit the source term, Elaborating strictly the specific chemical and shutdown procedure to optimize the purification capacity and to minimize the over-contaminations; Improving purification techniques according to the real operation circumstance, and limiting the impacts of these pollutants. It is obvious in the real practices that implementing appropriate solution will be benefit to decrease or limit the pollutants species like cobalt, silver and antimony. (author)

  9. Combined constraints on global ocean primary production using observations and models

    Science.gov (United States)

    Buitenhuis, Erik T.; Hashioka, Taketo; Quéré, Corinne Le

    2013-09-01

    production is at the base of the marine food web and plays a central role for global biogeochemical cycles. Yet global ocean primary production is known to only a factor of 2, with previous estimates ranging from 38 to 65 Pg C yr-1 and no formal uncertainty analysis. Here, we present an improved global ocean biogeochemistry model that includes a mechanistic representation of photosynthesis and a new observational database of net primary production (NPP) in the ocean. We combine the model and observations to constrain particulate NPP in the ocean with statistical metrics. The PlankTOM5.3 model includes a new photosynthesis formulation with a dynamic representation of iron-light colimitation, which leads to a considerable improvement of the interannual variability of surface chlorophyll. The database includes a consistent set of 50,050 measurements of 14C primary production. The model best reproduces observations when global NPP is 58 ± 7 Pg C yr-1, with a most probable value of 56 Pg C yr-1. The most probable value is robust to the model used. The uncertainty represents 95% confidence intervals. It considers all random errors in the model and observations, but not potential biases in the observations. We show that tropical regions (23°S-23°N) contribute half of the global NPP, while NPPs in the Northern and Southern Hemispheres are approximately equal in spite of the larger ocean area in the South.

  10. An improvement of satellite-based algorithm for gross primary production estimation optimized over Korea

    Science.gov (United States)

    Pi, Kyoung-Jin; Han, Kyung-Soo; Kim, In-Hwan; Kim, Sang-Il; Lee, Min-Ji

    2011-11-01

    Monitoring the global gross primary production (GPP) is relevant to understanding the global carbon cycle and evaluating the effects of interannual climate variation on food and fiber production. GPP, the flux of carbon into ecosystems via photosynthetic assimilation, is an important variable in the global carbon cycle and a key process in land surface-atmosphere interactions. The Moderate-resolution Imaging Spectroradiometer (MODIS) is one of the primary global monitoring sensors. MODIS GPP has some of the problems that have been proven in several studies. Therefore this study was to solve the regional mismatch that occurs when using the MODIS GPP global product over Korea. To solve this problem, we estimated each of the GPP component variables separately to improve the GPP estimates. We compared our GPP estimates with validation GPP data to assess their accuracy. For all sites, the correlation was close with high significance (R2 = 0.8164, RMSE = 0.6126 g.C.m-2.d-1, bias = -0.0271 g.C.m-2.d-1). We also compared our results to those of other models. The component variables tended to be either over- or under-estimated when compared to those in other studies over the Korean peninsula, although the estimated GPP was better. The results of this study will likely improve carbon cycle modeling by capturing finer patterns with an integrated method of remote sensing. Keywords: VEGETATION, Gross Primary Production, MODIS.

  11. Production of reduction gases: partial oxidation of hydrocarbons and coal

    Energy Technology Data Exchange (ETDEWEB)

    Tippmer, K

    1976-04-01

    After some general remarks on reduction gas and quality demands, the Texaco process of partial oxidation with scrubbing is dealt with. A comparison of current iron-sponge techniques shows that a heat demand below 3 M kcal/t Fe should be envisaged, which means that heavy fuel oil or coal should be used. The special features of oxygen generation, coal processing, demands made on fuel oil, gasoline, and natural gas, gas generation, soot recovery, hydrogen sulphide-carbon dioxide scrubbing, system Benfield HP process, recycle-carbon dioxide scrubbing, auxiliary steam system, gas preheating, recycle gas cooling and compression, process data and heat balances for natural gas (one-heat system) and heating fuel oil or naphtha (two-heat system) are given.

  12. Production of sized particles of uranium oxides and uranium oxyfluorides

    International Nuclear Information System (INIS)

    Knudsen, I.E.; Randall, C.C.

    1976-01-01

    A process is claimed for converting uranium hexafluoride (UF 6 ) to uranium dioxide (UO 2 ) of a relatively large particle size in a fluidized bed reactor by mixing uranium hexafluoride with a mixture of steam and hydrogen and by preliminary reacting in an ejector gaseous uranium hexafluoride with steam and hydrogen to form a mixture of uranium and oxide and uranium oxyfluoride seed particles of varying sizes, separating the larger particles from the smaller particles in a cyclone separator, recycling the smaller seed particles through the ejector to increase their size, and introducing the larger seed particles from the cyclone separator into a fluidized bed reactor where the seed particles serve as nuclei on which coarser particles of uranium dioxide are formed. 9 claims, 2 drawing figures

  13. Microstructural Analysis of the Oxidation Products of Metallic Alloys According to the HALOX Development

    International Nuclear Information System (INIS)

    De Micco, G.

    2001-01-01

    This publication is a first stage in the development of an oxidation process of the fissile material, from spent nuclear fuel elements of research reactors, containing molybdenum.The oxidation of molybdenum powder with air at elevated temperatures (375-500 o C) has been studied by means of X-ray diffraction and scanning electron microscopy.The results show that the only product was MoO 3 in two different phases: Monoclinic and Orthorhombic.MoO 2 and non-stoichiometric molybdenum oxide such as Mo 4 O 1 1 were not evidenced in any of the Mo oxidation steps. By monitoring the time required for the complete oxidation of Mo at different conditions of temperature and pressure, a rate equation has been determined for the whole process. The activation energy and the pressure and degree of reaction dependence, has been calculated.This values remain constant trough out the complete reaction

  14. Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

    International Nuclear Information System (INIS)

    Li, Yan; Chang, Jie; Ouyang, Yong; Zheng, Xianwei

    2014-01-01

    High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H 2 O 2 ) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS 4 )) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS 4 ). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS 4 )/H 2 O 2 was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS 4 )/H 2 O 2 system

  15. Productive vegetation: relationships between net primary productivity, vegetation types and climate change in the Wet Tropics bioregion

    International Nuclear Information System (INIS)

    Ramirez, Vanessa Valdez; Williams, Stephen E.; VanDerWal, Jeremy

    2007-01-01

    Full text: Full text: There is now ample evidence demonstrating the impacts of climate change on biodiversity and human society (Walther ef a/. 2002). Numerous studies have shown climate change is one of the most significant threats to tropical forests, such as the Wet Tropics Heritage Area, due to their high biodiversity and endemism (Pounds ef al. 1999; Hughes 2000; Parmesan and Yohe 2003). Williams ef al. (2003) suggested that small shifts in net primary productivity (NPP) as a result of climate change could lead to potentially massive follow-on effects for the extremely diverse and vulnerable rainforest flora and fauna. It is therefore crucial to explore the relationships between NPP and local biodiversity, especially to create models for different climate change scenarios. Nevertheless, NPP in the Wet Tropics has yet to be estimated. This is the first study to provide a general NPP estimate for the Wet Tropics bioregion using climate surrogates (Schuur 2003). This technique estimates NPP in an accurate, repeatable, and cost-effective way. NPP values were linked to vegetation types and examined under various climatic and environmental conditions. Results show a significant difference in productivity according to vegetation types and climatic variables, with temperature and rainfall seasonality as the most important determining variables. Additionally, lowland and upland vegetations showed a significant difference in productivity patterns throughout the year. Vegetation types located above 1000 metres in altitude had the lowest values of mean annual productivity due to their high rainfall and low temperatures; vegetation types located below 600 metres showed increased productivity values during the wet season (December-March). Net primary productivity will certainly be impacted by changes in temperature and rainfall, due to climate change. Although an increase in NPP values can be predicted for upland areas, the more widely distributed lowlands will drastically

  16. Temperature controls oxidative phosphorylation and reactive oxygen species production through uncoupling in rat skeletal muscle mitochondria.

    Science.gov (United States)

    Jarmuszkiewicz, Wieslawa; Woyda-Ploszczyca, Andrzej; Koziel, Agnieszka; Majerczak, Joanna; Zoladz, Jerzy A

    2015-06-01

    Mitochondrial respiratory and phosphorylation activities, mitochondrial uncoupling, and hydrogen peroxide formation were studied in isolated rat skeletal muscle mitochondria during experimentally induced hypothermia (25 °C) and hyperthermia (42 °C) compared to the physiological temperature of resting muscle (35 °C). For nonphosphorylating mitochondria, increasing the temperature from 25 to 42 °C led to a decrease in membrane potential, hydrogen peroxide production, and quinone reduction levels. For phosphorylating mitochondria, no temperature-dependent changes in these mitochondrial functions were observed. However, the efficiency of oxidative phosphorylation decreased, whereas the oxidation and phosphorylation rates and oxidative capacities of the mitochondria increased, with increasing assay temperature. An increase in proton leak, including uncoupling protein-mediated proton leak, was observed with increasing assay temperature, which could explain the reduced oxidative phosphorylation efficiency and reactive oxygen species production. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Biodiesel Production from Castor Oil by Using Calcium Oxide Derived from Mud Clam Shell

    Directory of Open Access Journals (Sweden)

    S. Ismail

    2016-01-01

    Full Text Available The catalytic potential of calcium oxide synthesized from mud clam shell as a heterogeneous catalyst for biodiesel production was studied. The mud clam shell calcium oxide was characterized using particle size analyzer, Fourier transform infrared spectroscopy, scanning electron microscopy, and BET gas sorption analyzer. The catalyst performance of mud clam shell calcium oxide was studied in the transesterification of castor oil as biodiesel. Catalyst characterization and transesterification study results of synthesized catalyst proved the efficiency of the natural derived catalyst for biodiesel production. A highest biodiesel yield of 96.7% was obtained at optimal parameters such as 1 : 14 oil-to-methanol molar ratio, 3% w/w catalyst concentration, 60°C reaction temperature, and 2-hour reaction time. Catalyst reusability test shows that the synthesized calcium oxide from mud clam shell is reusable up to 5 times.

  18. Oxidation of ciprofloxacin and enrofloxacin by ferrate(VI): Products identification, and toxicity evaluation

    International Nuclear Information System (INIS)

    Yang, Bin; Kookana, Rai S.; Williams, Mike; Ying, Guang-Guo; Du, Jun; Doan, Hai; Kumar, Anupama

    2016-01-01

    Ferrate(VI) (Fe(VI)) has been known to react with emerging organic contaminants containing electron-rich organic moieties, such as phenols, anilines, olefins, reduced sulfur and deprotonated amines. Oxidation of fluoroquinolone antibiotics, ciprofloxacin (CIP) and enrofloxacin (ENR), by Fe(VI) were investigated for their reaction products and toxicity changes as well as biodegradability of these products. Ten products were identified for both CIP and ENR reactions with Fe(VI) using a high-resolution accurate-mass Orbitrap mass analyzer. Structural changes to the CIP and ENR molecule included dealkylation, formation of alcohols and amides in piperazine ring and oxygen transfer to the double bond in quinolone structure. An enamine formation mechanism was tentatively proposed to facilitate the interpretation of CIP and ENR oxidation pathways. Toxicity evaluation using Microbial Assay for toxicity Risk Assessment (MARA) bioassay indicated that Fe(VI) oxidation products of CIP and ENR contributed negligible antibacterial potency and Fe(VI) oxidation treatment can remove the residual toxicity of CIP and ENR impacted source waters. The Fe(VI) oxidation treatment resulted in formation of relatively more biodegradable products (based on in silico assessment) than their corresponding parent compounds. The results showed that Fe(VI) has a good potential to degrade fluoroquinolone antibiotics and their antimicrobial potency in natural waters.

  19. Oxidation of ciprofloxacin and enrofloxacin by ferrate(VI): Products identification, and toxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin, E-mail: Bin.Yang@csiro.au [CSIRO Land and Water, Waite Campus, PMB 2, Glen Osmond, South Australia 5064 (Australia); Kookana, Rai S.; Williams, Mike [CSIRO Land and Water, Waite Campus, PMB 2, Glen Osmond, South Australia 5064 (Australia); Ying, Guang-Guo [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Du, Jun; Doan, Hai; Kumar, Anupama [CSIRO Land and Water, Waite Campus, PMB 2, Glen Osmond, South Australia 5064 (Australia)

    2016-12-15

    Ferrate(VI) (Fe(VI)) has been known to react with emerging organic contaminants containing electron-rich organic moieties, such as phenols, anilines, olefins, reduced sulfur and deprotonated amines. Oxidation of fluoroquinolone antibiotics, ciprofloxacin (CIP) and enrofloxacin (ENR), by Fe(VI) were investigated for their reaction products and toxicity changes as well as biodegradability of these products. Ten products were identified for both CIP and ENR reactions with Fe(VI) using a high-resolution accurate-mass Orbitrap mass analyzer. Structural changes to the CIP and ENR molecule included dealkylation, formation of alcohols and amides in piperazine ring and oxygen transfer to the double bond in quinolone structure. An enamine formation mechanism was tentatively proposed to facilitate the interpretation of CIP and ENR oxidation pathways. Toxicity evaluation using Microbial Assay for toxicity Risk Assessment (MARA) bioassay indicated that Fe(VI) oxidation products of CIP and ENR contributed negligible antibacterial potency and Fe(VI) oxidation treatment can remove the residual toxicity of CIP and ENR impacted source waters. The Fe(VI) oxidation treatment resulted in formation of relatively more biodegradable products (based on in silico assessment) than their corresponding parent compounds. The results showed that Fe(VI) has a good potential to degrade fluoroquinolone antibiotics and their antimicrobial potency in natural waters.

  20. Nitrous Oxide Production in a Granule-based Partial Nitritation Reactor: A Model-based Evaluation.

    Science.gov (United States)

    Peng, Lai; Sun, Jing; Liu, Yiwen; Dai, Xiaohu; Ni, Bing-Jie

    2017-04-03

    Sustainable wastewater treatment has been attracting increasing attentions over the past decades. However, the production of nitrous oxide (N 2 O), a potent GHG, from the energy-efficient granule-based autotrophic nitrogen removal is largely unknown. This study applied a previously established N 2 O model, which incorporated two N 2 O production pathways by ammonia-oxidizing bacteria (AOB) (AOB denitrification and the hydroxylamine (NH 2 OH) oxidation). The two-pathway model was used to describe N 2 O production from a granule-based partial nitritation (PN) reactor and provide insights into the N 2 O distribution inside granules. The model was evaluated by comparing simulation results with N 2 O monitoring profiles as well as isotopic measurement data from the PN reactor. The model demonstrated its good predictive ability against N 2 O dynamics and provided useful information about the shift of N 2 O production pathways inside granules for the first time. The simulation results indicated that the increase of oxygen concentration and granule size would significantly enhance N 2 O production. The results further revealed a linear relationship between N 2 O production and ammonia oxidation rate (AOR) (R 2  = 0.99) under the conditions of varying oxygen levels and granule diameters, suggesting that bulk oxygen and granule size may exert an indirect effect on N 2 O production by causing a change in AOR.

  1. Thermal Oxidation of Tail Gases from the Production of Oil-furnace Carbon Black

    Directory of Open Access Journals (Sweden)

    Bosak, Z.

    2009-01-01

    Full Text Available This paper describes the production technology of oil-furnace carbon black, as well as the selected solution for preventing the emissions of this process from contaminating the environment.The products of industrial oil-furnace carbon black production are different grades of carbon black and process tail gases. The qualitative composition of these tail gases during the production of oil-furnace carbon black are: carbon(IV oxide, carbon(II oxide, hydrogen, methane, hydrogen sulfide, nitrogen, oxygen, and water vapor.The quantitative composition and lower caloric value of process tail gases change depending on the type of feedstock used in the production, as well as the type of process. The lower caloric value of process tail gases is relatively small with values ranging between 1500 and 2300 kJ m–3.In the conventional production of oil-furnace carbon black, process tail gases purified from carbon black dust are freely released into the atmosphere untreated. In this manner, the process tail gases pollute the air in the town of Kutina, because their quantitative values are much higher than the prescribed emissions limits for hydrogen sulfide and carbon(II oxide. A logical solution for the prevention of such air pollution is combustion of the process tail gases, i. e. their thermal oxidation. For this purpose, a specially designed flare system has been developed. Consuming minimum amounts of natural gas needed for oxidation, the flare system is designed to combust low caloric process tail gases with 99 % efficiency. Thus, the toxic and flammable components of the tail gases (hydrogen sulfide, hydrogen, carbon(II oxide, methane and other trace hydrocarbons would be transformed into environmentally acceptable components (sulfur(IV oxide, water, carbon(IV oxide and nitrogen(IV oxide, which are in compliance with the emissions limit values prescribed by law.Proper operation of this flare system in the production of oil-furnace carbon black would solve

  2. Redox-neutral rhodium-catalyzed C-H functionalization of arylamine N-oxides with diazo compounds: primary C(sp(3))-H/C(sp(2))-H activation and oxygen-atom transfer.

    Science.gov (United States)

    Zhou, Bing; Chen, Zhaoqiang; Yang, Yaxi; Ai, Wen; Tang, Huanyu; Wu, Yunxiang; Zhu, Weiliang; Li, Yuanchao

    2015-10-05

    An unprecedented rhodium(III)-catalyzed regioselective redox-neutral annulation reaction of 1-naphthylamine N-oxides with diazo compounds was developed to afford various biologically important 1H-benzo[g]indolines. This coupling reaction proceeds under mild reaction conditions and does not require external oxidants. The only by-products are dinitrogen and water. More significantly, this reaction represents the first example of dual functiaonalization of unactivated a primary C(sp(3) )H bond and C(sp(2) )H bond with diazocarbonyl compounds. DFT calculations revealed that an intermediate iminium is most likely involved in the catalytic cycle. Moreover, a rhodium(III)-catalyzed coupling of readily available tertiary aniline N-oxides with α-diazomalonates was also developed under external oxidant-free conditions to access various aminomandelic acid derivatives by an O-atom-transfer reaction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Production of nitrous oxide in the auroral D and E regions

    Science.gov (United States)

    Zipf, E. C.; Prasad, S. S.

    1980-01-01

    A study of nitrous oxide formation mechanisms indicates that N2O concentrations greater than 10 to the 9th per cu cm could be produced in IBC III aurora or by lower-level activity lasting for many hours, and, in favorable conditions, the N2O concentration could exceed the local nitric oxide density. An upper limit on the globally averaged N2O production rate from auroral activity is estimated at 2 x 10 to the 27th per second.

  4. Field study of nitrous oxide production with in situ aeration in a closed landfill site.

    Science.gov (United States)

    Nag, Mitali; Shimaoka, Takayuki; Nakayama, Hirofumi; Komiya, Teppei; Xiaoli, Chai

    2016-03-01

    Nitrous oxide (N(2)O) has gained considerable attention as a contributor to global warming and depilation of stratospheric ozone layer. Landfill is one of the high emitters of greenhouse gas such as methane and N(2)O during the biodegradation of solid waste. Landfill aeration has been attracted increasing attention worldwide for fast, controlled and sustainable conversion of landfills into a biological stabilized condition, however landfill aeration impel N(2)O emission with ammonia removal. N(2)O originates from the biodegradation, or the combustion of nitrogen-containing solid waste during the microbial process of nitrification and denitrification. During these two processes, formation of N(2)O as a by-product from nitrification, or as an intermediate product of denitrification. In this study, air was injected into a closed landfill site and investigated the major N(2)O production factors and correlations established between them. The in-situ aeration experiment was carried out by three sets of gas collection pipes along with temperature probes were installed at three different distances of one, two and three meter away from the aeration point; named points A-C, respectively. Each set of pipes consisted of three different pipes at three different depths of 0.0, 0.75 and 1.5 m from the bottom of the cover soil. Landfill gases composition was monitored weekly and gas samples were collected for analysis of nitrous oxide concentrations. It was evaluated that temperatures within the range of 30-40°C with high oxygen content led to higher generation of nitrous oxide with high aeration rate. Lower O(2) content can infuse N(2)O production during nitrification and high O(2) inhibit denitrification which would affect N(2)O production. The findings provide insights concerning the production potentials of N(2)O in an aerated landfill that may help to minimize with appropriate control of the operational parameters and biological reactions of N turnover. Investigation of

  5. MODIS/Terra Gross Primary Productivity 8-Day L4 Global 1km SIN Grid V055

    Data.gov (United States)

    National Aeronautics and Space Administration — The Terra/MODIS Gross Primary Productivity (GPP) product (MOD17A2) is a cumulative composite of GPP values based on the radiation-use efficiency concept that is...

  6. Nitric oxide production by rat bronchoalveolar macrophages or ...

    Indian Academy of Sciences (India)

    Unknown

    inflammatory responses to either LPS or silica. For in- stance, the capacity of AMs to respond directly to LPS with increases in NO production has been well docu- mented (Jorens et al 1991; Warner et al 1995). AMs also are a likely source of the NO produced following silica exposure (Huffman et al 1998; Porter et al 2002).

  7. Nitric oxide production by rat bronchoalveolar macrophages or ...

    Indian Academy of Sciences (India)

    Unknown

    Media levels of nitrate and nitrite (NOx; the stable decomposition products of NO) ... have the capacity to express iNOS mRNA and produce. NO, much of ... Sil, < 5 µm diameter, US Silica Corp., Berkeley Springs, ..... provides new information.

  8. Variation in excess oxidant factor in combustion products of MHD generator. [Natural gas fuel

    Energy Technology Data Exchange (ETDEWEB)

    Pinkhasik, M S; Mironov, V D; Zakharko, Yu A; Plavinskii, A I

    1977-12-01

    Methods and difficulties associated with determining the excess oxidant factor for natural gas-fired MHD generators are discussed. The measurement of this factor is noted to be essential for the optimization of the combustion chamber and operation of MHD generators. A gas analyzer of electrochemical type is considered as a quick - response sensor capable of analyzing the composition of the combustion products and thus determining accurately the excess oxidant factor. The principle of operation of this sensor is discussed and the dependence of the electrochemical sensor emf on excess oxidant factor is shown. Three types of sensors are illustrated and tables of test results are provided.

  9. Outcome of zinc oxide eugenol paste as an obturating material in primary teeth pulpectomy: A systematic review

    Directory of Open Access Journals (Sweden)

    Harsha S Nalawade

    2017-01-01

    Full Text Available The aim of this systematic review is to use the principles of evidence-based dentistry to evaluate the outcome of zinc oxide eugenol (ZOE paste as an obturating material in primary teeth pulpectomies. Moderate-to-high success rates are reported with ZOE in preserving chronically infected primary teeth. However, it fails to meet many of the criteria for an ideal obturating material. Databases searched were PubMed, EBSCOhost, and Google Scholar. Articles published between January 1, 1993, and June 30, 2016, with in vivo studies for obturating materials in primary teeth pulpectomy with placement of preformed crown, reporting follow-up period of at least 12 months with clinical and radiographic success rates were selected for this review. In total, 122 articles were retrieved. After the removal of duplicates and screening, full-text articles were analyzed; of which eight articles were selected for the systematic review. No significant difference was seen in the outcome of obturating materials used in comparison with ZOE in the included studies. Outcomes of ZOE paste obtained with clinical and radiographic evaluation were similar when compared to the newer combinations of materials available for obturating primary teeth today. More number of randomized controlled clinical trials for primary teeth pulpectomies with at least 12 months follow-up period and placement of crown as final restoration need to be carried out for testing the newer materials in comparison with ZOE to conclude a suitable alternative obturating material.

  10. Oxidized lipids enhance RANKL production by T lymphocytes: implications for lipid-induced bone loss.

    Science.gov (United States)

    Graham, Lucia S; Parhami, Farhad; Tintut, Yin; Kitchen, Christina M R; Demer, Linda L; Effros, Rita B

    2009-11-01

    Osteoporosis is a systemic disease that is associated with increased morbidity, mortality and health care costs. Whereas osteoclasts and osteoblasts are the main regulators of bone homeostasis, recent studies underscore a key role for the immune system, particularly via activation-induced T lymphocyte production of receptor activator of NFkappaB ligand (RANKL). Well-documented as a mediator of T lymphocyte/dendritic cell interactions, RANKL also stimulates the maturation and activation of bone-resorbing osteoclasts. Given that lipid oxidation products mediate inflammatory and metabolic disorders such as osteoporosis and atherosclerosis, and since oxidized lipids affect several T lymphocyte functions, we hypothesized that RANKL production might also be subject to modulation by oxidized lipids. Here, we show that short term exposure of both unstimulated and activated human T lymphocytes to minimally oxidized low density lipoprotein (LDL), but not native LDL, significantly enhances RANKL production and promotes expression of the lectin-like oxidized LDL receptor-1 (LOX-1). The effect, which is also observed with 8-iso-Prostaglandin E2, an inflammatory isoprostane produced by lipid peroxidation, is mediated via the NFkappaB pathway, and involves increased RANKL mRNA expression. The link between oxidized lipids and T lymphocytes is further reinforced by analysis of hyperlipidemic mice, in which bone loss is associated with increased RANKL mRNA in T lymphocytes and elevated RANKL serum levels. Our results suggest a novel pathway by which T lymphocytes contribute to bone changes, namely, via oxidized lipid enhancement of RANKL production. These findings may help elucidate clinical associations between cardiovascular disease and decreased bone mass, and may also lead to new immune-based approaches to osteoporosis.

  11. MnTM-4-PyP modulates endogenous antioxidant responses and protects primary cortical neurons against oxidative stress.

    Science.gov (United States)

    Cheng, Kuo-Yuan; Guo, Fei; Lu, Jia-Qi; Cao, Yuan-Zhao; Wang, Tian-Chang; Yang, Qi; Xia, Qing

    2015-05-01

    Oxidative stress is a direct cause of injury in various neural diseases. Manganese porphyrins (MnPs), a large category of superoxide dismutase (SOD) mimics, shown universally to have effects in numerous neural disease models in vivo. Given their complex intracellular redox activities, detailed mechanisms underlying the biomedical efficacies are not fully elucidated. This study sought to investigate the regulation of endogenous antioxidant systems by a MnP (MnTM-4-PyP) and its role in the protection against neural oxidative stress. Primary cortical neurons were treated with MnTM-4-PyP prior to hydrogen peroxide-induced oxidative stress. MnTM-4-PyP increased cell viability, reduced intracellular level of reactive oxygen species, inhibited mitochondrial apoptotic pathway, and ameliorated endoplasmic reticulum function. The protein levels and activities of endogenous SODs were elevated, but not those of catalase. SOD2 transcription was promoted in a transcription factor-specific manner. Additionally, we found FOXO3A and Sirt3 levels also increased. These effects were not observed with MnTM-4-PyP alone. Induction of various levels of endogenous antioxidant responses by MnTM-4-PyP has indispensable functions in its protection for cortical neurons against hydrogen peroxide-induced oxidative stress. © 2014 John Wiley & Sons Ltd.

  12. Nitrous oxide production pathways in a partial nitritation-anammox reactor: Isotopic evidence for nitrous oxide production associated anaerobic ammonium oxidation?

    Science.gov (United States)

    Wunderlin, P.; Harris, E. J.; Joss, A.; Emmenegger, L.; Kipf, M.; Mohn, J.; Siegrist, H.

    2014-12-01

    Nitrous oxide (N2O) is a strong greenhouse gas and a major sink for stratospheric ozone. In biological wastewater treatment N2O can be produced via several pathways. This study investigates the dynamics of N2O emissions from a nitritation-anammox reactor, and links its interpretation to the nitrogen and oxygen isotopic signature of the emitted N2O. A 400-litre single-stage nitritation-anammox reactor was operated and continuously fed with digester liquid. The isotopic composition of N2O emissions was monitored online with quantum cascade laser absorption spectroscopy (QCLAS; Aerodyne Research, Inc.; Waechter et al., 2008). Dissolved ammonium and nitrate were monitored online (ISEmax, Endress + Hauser), while nitrite was measured with test strips (Nitrite-test 0-24mgN/l, Merck). Table 1. Summary of experiments conducted to understand N2O emissions Experimental conditions O2[mgO2/L] NO2-[mgN/L] NH4+[mgN/L] N2O/NH4+[%] Normal operation production pathway, which is hypothesized to be mediated by anammox activity (Figure 1). A less likely explanation is that the SP of N2O was increased by partial N2O reduction by heterotrophic denitrification. Various experiments were conducted to further investigate N2O formation pathways in the reactor. Our data reveal that N2O emissions increased when reactor operation was not ideal, for example when dissolved oxygen was too high (Table 1). SP measurements confirmed that these N2O peaks were due to enhanced nitrifier denitrification, generally related to nitrite build-up in the reactor (Figure 1; Table 1). Overall, process control via online N2O monitoring was confirmed to be an ideal method to detect imbalances in reactor operation and regulate aeration, to ensure optimal reactor conditions and minimise N2O emissions. ReferencesWaechter H. et al. (2008) Optics Express, 16: 9239-9244. Wunderlin, P et al. (2013) Environmental Science & Technology 47: 1339-1348.

  13. Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

    Directory of Open Access Journals (Sweden)

    Josep M. Gasol

    2016-09-01

    Full Text Available We carried out monthly photosynthesis-irradiance (P-E experiments with the 14C-method for 12 years (2003–2014 to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1, averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1–1 (±0.001 SE, range 0.001-0.045 and showed the lowest values in spring (April-June. The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (± 58.4 SE and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m-3 h–1 (±0.13 SE with highest values in winter (up to 8.50 mg C m-3 h–1 and lowest values in summer (summer average, 0.30 mg C m-3 h–1, while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August. 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while

  14. Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

    KAUST Repository

    Gasol, Josep M.

    2016-10-11

    We carried out monthly photosynthesis-irradiance (P-E) experiments with the 14C-method for 12 years (2003–2014) to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1), averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE) and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1)–1 (±0.001 SE, range 0.001-0.045) and showed the lowest values in spring (April-June). The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (±58.4 SE) and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m–3 h–1 (±0.13 SE) with highest values in winter (up to 8.50 mg C m–3 h–1) and lowest values in summer (summer average, 0.30 mg C m–3 h–1), while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE) and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August). 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while

  15. Primary producers and production in Hornsund and Kongsfjorden – comparison of two fjord systems

    Directory of Open Access Journals (Sweden)

    Smoła Zofia T.

    2017-09-01

    Full Text Available Hornsund and Kongsfjorden are two similar-sized Arctic fjords on the West coast of Spitsbergen. They are influenced by cold coastal Arctic water (Hornsund and warmer Atlantic water (Kongsfjorden. Environmental conditions affect the timing, quantity, spatial distribution (horizontal and vertical of spring and summer blooms of protists as well as the taxonomic composition of those assemblages. Here, we compile published data and unpublished own measurement from the past two decades to compare the environmental factors and primary production in two fjord systems. Kongsfjorden is characterized by a deeper euphotic zone, higher biomass and greater proportion of autotrophic species. Hornsund seems to obtain more nutrients due to the extensive seabird colonies and exhibits higher turbidity compared to Kongsfjorden. The annual primary production in the analysed fjords ranges from 48 g C m−2 y−1 in Kongsfjorden to 216 g C m−2 y−1 in Hornsund, with a dominant component of microplankton (90% followed by macrophytes and microphytobenthos.

  16. Activation of the PI3K/Akt pathway by oxidative stress mediates high glucose-induced increase of adipogenic differentiation in primary rat osteoblasts.

    Science.gov (United States)

    Zhang, Yu; Yang, Jian-Hong

    2013-11-01

    Diabetes mellitus is associated with increased risk of osteopenia and bone fracture that may be related to hyperglycemia. However, the mechanisms accounting for diabetic bone disorder are unclear. Here, we showed that high glucose significantly promoted the production of reactive oxygen species (ROS) in rat primary osteoblasts. Most importantly, we reported for the first time that ROS induced by high glucose increased alkaline phosphatase activity, inhibited type I collagen (collagen I) protein level and cell mineralization, as well as gene expression of osteogenic markers including runt-related transcription factor 2 (Runx2), collagen I, and osteocalcin, but promoted lipid droplet formation and gene expression of adipogenic markers including peroxisome proliferator-activated receptor gamma, adipocyte fatty acid binding protein (aP2), and adipsin, which were restored by pretreatment with N-acetyl-L-cysteine (NAC), a ROS scavenger. Moreover, high glucose-induced oxidative stress activated PI3K/Akt pathway to inhibited osteogenic differentiation but stimulated adipogenic differentiation. In contrast, NAC and a PI3K inhibitor, LY-294002, reversed the down-regulation of osteogenic markers and the up-regulation of adipogenic markers as well as the activation of Akt under high glucose. These results indicated that oxidative stress played a key role in high glucose-induced increase of adipogenic differentiation, which contributed to the inhibition of osteogenic differentiation. This process was mediated by PI3K/Akt pathway in rat primary osteoblasts. Hence, suppression of oxidative stress could be a potential therapeutic approach for diabetic osteopenia. © 2013 Wiley Periodicals, Inc.

  17. Estimators of primary production for interpretation of remotely sensed data on ocean color

    Science.gov (United States)

    Platt, Trevor; Sathyendranath, Shubha

    1993-01-01

    The theoretical basis is explained for some commonly used estimators of daily primary production in a vertically uniform water column. These models are recast into a canonical form, with dimensionless arguments, to facilitate comparison with each other and with an analytic solution. The limitations of each model are examined. The values of the photoadaptation parameter I(k) observed in the ocean are analyzed, and I(k) is used as a scale to normalize the surface irradiance. The range of this scaled irradiance is presented. An equation is given for estimation of I(k) from recent light history. It is shown how the models for water column production can be adapted for estimation of the production in finite layers. The distinctions between model formulation, model implementation and model evaluation are discussed. Recommendations are given on the choice of algorithm for computation of daily production according to the degree of approximation acceptable in the result.

  18. Classification and calculation of primary failure modes in bread production line

    International Nuclear Information System (INIS)

    Tsarouhas, Panagiotis H.

    2009-01-01

    In this study, we describe the classification methodology over a 2-year period of the primary failure modes in categories based on failure data of bread production line. We estimate the probabilities of these categories applying the chi-square goodness of fit test, and we calculate their joint probabilities of mass function at workstation and line level. Then, we present numerical examples in order to predict the causes and frequencies of breakdowns for workstations and for the entire bread production line that will occur in the future. The methodology is meant to guide bread and bakery product manufacturers, improving the operation of the production lines. It can also be a useful tool to maintenance engineers, who wish to analyze and improve the reliability and efficiency of the manufacturing systems

  19. High production volume chemical Amine Oxide [C8-C20] category environmental risk assessment

    DEFF Research Database (Denmark)

    Sanderson, Hans; Tibazarwa, Caritas; Greggs, William

    2009-01-01

    and personal care products. Given the lack of persistence or bioaccumulation, and the low likelihood of these chemicals partitioning to soil, the focus of the environmental assessment is on the aquatic environment. In the United States, the E-FAST model is used to estimate effluent concentrations in the United......An environmental assessment of amine oxides has been conducted under the OECD SIDS High Production Volume (HPV) Program via the Global International Council of Chemical Associations (ICCA) Amine Oxides Consortium. Amine oxides are primarily used in conjunction with surfactants in cleaning...... States from manufacturing facilities and from municipal facilities resulting from consumer product uses. Reasonable worst-case ratios of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) range from 0.04 to 0.003, demonstrating that these chemicals are a low risk...

  20. The Absorption of Light in Lakes: Negative Impact of Dissolved Organic Carbon on Primary Productivity

    OpenAIRE

    Thrane, Jan-Erik; Hessen, Dag O.; Andersen, Tom

    2014-01-01

    Colored dissolved organic matter (CDOM) absorbs a substantial fraction of photosynthetically active radiation (PAR) in boreal lakes. However, few studies have systematically estimated how this light absorption influences pelagic primary productivity. In this study, 75 boreal lakes spanning wide and orthogonal gradients in dissolved organic carbon (DOC) and total phosphorus (TP) were sampled during a synoptic survey. We measured absorption spectra of phytoplankton pigments, CDOM, and non-algal...

  1. Creating a Regional MODIS Satellite-Driven Net Primary Production Dataset for European Forests

    OpenAIRE

    Neumann, Mathias; Moreno, Adam; Thurnher, Christopher; Mues, Volker; Härkönen, Sanna; Mura, Matteo; Bouriaud, Olivier; Lang, Mait; Cardellini, Giuseppe; Thivolle-Cazat, Alain; Bronisz, Karol; Merganic, Jan; Alberdi, Iciar; Astrup, Rasmus; Mohren, Frits

    2016-01-01

    Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm provides valuable information for monitoring NPP at 1-km resolution. Since coarse-resolution global climate data are used, the global dataset may contain uncertainties for Europe. We used a 1-km daily g...

  2. Impacts of temperature on primary productivity and respiration in naturally structured macroalgal assemblages.

    Directory of Open Access Journals (Sweden)

    Leigh W Tait

    Full Text Available Rising global temperatures caused by human-mediated change has already triggered significant responses in organismal physiology, distribution and ecosystem functioning. Although the effects of rising temperature on the physiology of individual organisms are well understood, the effect on community-wide processes has remained elusive. The fixation of carbon via primary productivity is an essential ecosystem function and any shifts in the balance of primary productivity and respiration could alter the carbon balance of ecosystems. Here we show through a series of tests that respiration of naturally structured algal assemblages in southern New Zealand greatly increases with rising temperature, with implications for net primary productivity (NPP. The NPP of in situ macroalgal assemblages was minimally affected by natural temperature variation, possibly through photo-acclimation or temperature acclimation responses, but respiration rates and compensating irradiance were negatively affected. However, laboratory experiments testing the impacts of rising temperature on several photosynthetic parameters showed a decline in NPP, increasing respiration rates and increasing compensating irradiance. The respiration Q10 of laboratory assemblages (the difference in metabolic rates over 10°C averaged 2.9 compared to a Q10 of 2 often seen in other autotrophs. However, gross primary productivity (GPP Q10 averaged 2, indicating that respiration was more severely affected by rising temperature. Furthermore, combined high irradiance and high temperature caused photoinhibition in the laboratory, and resulted in 50% lower NPP at high irradiance. Our study shows that communities may be more severely affected by rising global temperatures than would be expected by responses of individual species. In particular, enhanced respiration rates and rising compensation points have the potential to greatly affect the carbon balance of macroalgal assemblages through declines in

  3. Primary and secondary metabolites production in signal grass around the year under nitrogen fertilizer

    OpenAIRE

    Syeda Maryam Hussain

    2016-01-01

    Plants produce a number of substances and products and primary and secondary metabolites (SM) are amongst them with many benefits but limitation as well. Usually, the fodder are not considered toxic to animals or as a source having higher SM. The Brachiaria decumbens has a considerable nutritional value, but it is considered as a toxic grass for causing photosensitization in animals, if the grass is not harvested for more than 30 days or solely. The absence of detailed information in the lite...

  4. Nano tubular Transition Metal Oxide for Hydrogen Production

    International Nuclear Information System (INIS)

    Sreekantan, S.; San, E.P.; Kregvirat, W.; Wei, L.C.

    2011-01-01

    TiO 2 , transition metal oxide nano tubes were successfully grown by anodizing of titanium foil (Ti) in ethylene glycol electrolyte containing 5wt. % hydrogen peroxide and 5wt. % ammonium fluoride for 60 minutes at 60V. It was found such electrochemical condition resulted in the formation of nano tube with average diameter of 90nm and length of 6.6 μm. These samples were used to study the effect of W loading by RF sputtering on TiO 2 nano tubes. Amorphous TiO 2 nano tube substrate leads to enhance incorporation of W instead of anatase. Therefore for the entire study, W was sputtered on amorphous TiO 2 nano tube substrate. TiO 2 nano tube sputtered for 1 minute resulted in the formation of W-O-Ti while beyond this point (10 minutes); it accumulates to form a self independent structure of WO 3 on the surface of the nano tubes. TiO 2 nano tube sputtered for 1 minute at 150 W and annealed at 450 degree Celsius exhibited best photocurrent density (1.4 mA/ cm 2 ) with photo conversion efficiency of 2.5 %. The reason for such behavior is attributed to W 6+ ions allows for electron traps that suppress electron hole recombination and exploit the lower band gap of material to produce a water splitting process by increasing the charge separation and extending the energy range of photoexcitation for the system. (author)

  5. Primary and heterotrophic productivity relate to multikingdom diversity in a hypersaline mat

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Hans C.; Brislawn, Colin J.; Dana, Karl; Flores-Wentz, Tobias; Cory, Alexandra B.; Fansler, Sarah J.; Fredrickson, James K.; Moran, James J.

    2017-10-01

    Benthic microbial ecosystems are widespread yet knowledge gaps still remain on the relationships between the diversity of species across kingdoms and productivity. Here, we ask two fundamental questions: 1) How does species diversity relate to the rates of primary and heterotrophic productivity? 2) How do diel variations in light-energy inputs influence productivity and microbiome diversity? To answer these questions, microbial mats from a magnesium sulfate hypersaline Lake were used to establish microcosms. Both the number and relatedness between bacterial and eukaryotic taxa in the microbiome were assayed via amplicon based sequencing of 16S and 18S rRNA genes over two diel cycles. These results correlated with biomass productivity obtained from substrate-specific 13C stable isotope incorporation that enabled comparisons between primary and heterotrophic productivity. Both bacterial and eukaryotic species richness and evenness were related only to the rates of 13C labeled glucose and acetate biomass incorporation. Interestingly, measures of these heterotrophic relationships changed from positive and negative correlations depending on carbon derived from glucose and acetate, respectively. Bacterial and eukaryotic diversity of this ecosystem is also controlled, in part, energy constraints imposed by changing irradiance over a diel cycle.

  6. Diagnosis of compliance of health care product processing in Primary Health Care

    Directory of Open Access Journals (Sweden)

    Camila Eugenia Roseira

    Full Text Available ABSTRACT Objective: identify the compliance of health care product processing in Primary Health Care and assess possible differences in the compliance among the services characterized as Primary Health Care Service and Family Health Service. Method: quantitative, observational, descriptive and inferential study with the application of structure, process and outcome indicators of the health care product processing at ten services in an interior city of the State of São Paulo - Brazil. Results: for all indicators, the compliance indices were inferior to the ideal levels. No statistically significant difference was found in the indicators between the two types of services investigated. The health care product cleaning indicators obtained the lowest compliance index, while the indicator technical-operational resources for the preparation, conditioning, disinfection/sterilization, storage and distribution of health care products obtained the best index. Conclusion: the diagnosis of compliance of health care product processing at the services assessed indicates that the quality of the process is jeopardized, as no results close to ideal levels were obtained at any service. In addition, no statistically significant difference in these indicators was found between the two types of services studied.

  7. MIS High-Purity Plutonium Oxide Metal Oxidation Product TS707001 (SSR123): Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stroud, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Narlesky, Joshua Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Max A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carillo, Alex [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-09

    A high-purity plutonium dioxide material from the Material Identification and Surveillance (MIS) Program inventory has been studied with regard to gas generation and corrosion in a storage environment. Sample TS707001 represents process plutonium oxides from several metal oxidation operations as well as impure and scrap plutonium from Hanford that are currently stored in 3013 containers. After calcination to 950°C, the material contained 86.98% plutonium with no major impurities. This study followed over time, the gas pressure of a sample with nominally 0.5 wt% water in a sealed container with an internal volume scaled to 1/500th of the volume of a 3013 container. Gas compositions were measured periodically over a six year period. The maximum observed gas pressure was 138 kPa. The increase over the initial pressure of 80 kPa was primarily due to generation of nitrogen and carbon dioxide gas in the first six months. Hydrogen and oxygen were minor components of the headspace gas. At the completion of the study, the internal components of the sealed container showed signs of corrosion, including pitting.

  8. Oxide layers of Zr-1% Nb under PWR primary circuit conditions

    International Nuclear Information System (INIS)

    Nagy, Gabor; Kerner, Zsolt; Battistig, Gabor; Pinter-Csordas, Anna; Balogh, Janos; Pajkossy, Tamas

    2001-01-01

    Oxide layers were grown on Zr-1% Nb under conditions simulating those in VVER-type pressurised water reactors (PWRs), viz. in borate solutions in an autoclave at 290 deg. C. The layers were characterised by various methods: their respective thickness values were determined by weight gain measurements, Rutherford backscattering (RBS), nuclear reaction analysis (NRA) and scanning electron microscopy (SEM); the electrical properties were tested by electrochemical impedance spectroscopy. The results show that the oxide layer on Zr-1% Nb is homogeneous and somewhat thicker than that on Zircaloy-4

  9. Enhancing lipid productivity of Chlorella vulgaris using oxidative stress by TiO2 nanoparticles

    International Nuclear Information System (INIS)

    Kang, Nam Kyu; Lee, Bongsoo; Choi, Gang-Guk; Moon, Myounghoon; Park, Min S.; Yang, Ji-Won; Lim, JitKang

    2014-01-01

    Ability to increase the lipid production in microalgae is one of the heavily sought-after ideas to improve the economic feasibility of microalgae-derived transportation fuels for commercial applications. We used the oxidative stress by TiO 2 nanoparticles, a well-known photocatalyst, to induce lipid production in microalgae. Chlorella vulgaris UTEX 265 was cultivated under various concentrations of TiO 2 ranging from 0.1 to 5 g/L under UV-A illumination. Maximum specific growth rate was affected in responding to TiO 2 concentrations. In the presence of UV-A, chlorophyll concentration was decreased at the highest concentration of TiO 2 (5 g/L TiO 2 ) by oxidative stress. The fatty acid methyl ester (FAME) composition analysis suggested that oxidative stress causes the accumulation and decomposition of lipids. The highest FAME productivity was 18.2 g/L/d under low concentrations of TiO 2 (0.1 g/L) and a short induction time (two days). The controlled condition of TiO 2 /UV-A inducing oxidative stress (0.1 g/L TiO 2 and two days induction) could be used to increase the lipid productivity of C. vulgaris UTEX 265. Our results show the possibility of modulating the lipid induction process through oxidative stress with TiO 2 /UV-A

  10. Enhancing lipid productivity of Chlorella vulgaris using oxidative stress by TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Nam Kyu; Lee, Bongsoo; Choi, Gang-Guk; Moon, Myounghoon; Park, Min S.; Yang, Ji-Won [Daejeon, Daejeon (Korea, Republic of); Lim, JitKang [Universiti Sains Malaysia, Penang (Malaysia)

    2014-05-15

    Ability to increase the lipid production in microalgae is one of the heavily sought-after ideas to improve the economic feasibility of microalgae-derived transportation fuels for commercial applications. We used the oxidative stress by TiO{sub 2} nanoparticles, a well-known photocatalyst, to induce lipid production in microalgae. Chlorella vulgaris UTEX 265 was cultivated under various concentrations of TiO{sub 2} ranging from 0.1 to 5 g/L under UV-A illumination. Maximum specific growth rate was affected in responding to TiO{sub 2} concentrations. In the presence of UV-A, chlorophyll concentration was decreased at the highest concentration of TiO{sub 2} (5 g/L TiO{sub 2}) by oxidative stress. The fatty acid methyl ester (FAME) composition analysis suggested that oxidative stress causes the accumulation and decomposition of lipids. The highest FAME productivity was 18.2 g/L/d under low concentrations of TiO{sub 2} (0.1 g/L) and a short induction time (two days). The controlled condition of TiO{sub 2}/UV-A inducing oxidative stress (0.1 g/L TiO{sub 2} and two days induction) could be used to increase the lipid productivity of C. vulgaris UTEX 265. Our results show the possibility of modulating the lipid induction process through oxidative stress with TiO{sub 2}/UV-A.

  11. Serum Antioxidative Enzymes Levels and Oxidative Stress Products in Age-Related Cataract Patients

    Directory of Open Access Journals (Sweden)

    Dong Chang

    2013-01-01

    Full Text Available Purpose. To investigate the activity of antioxidative enzymes and the products of oxidative stress in patients with age-related cataracts and compare the findings with those in healthy control subjects. Method. Sixty patients with age-related cataract and sixty healthy controls of matched age and gender were included in this study. Serum samples were obtained to detect the antioxidative enzymes of superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px, and oxidation degradation products of malondialdehyde (MDA, 4-hydroxynonenal (4-HNE, conjugated diene (CD, advanced oxidation protein products (AOPP, protein carbonyl (PC, and 8-hydroxydeoxyguanosine (8-OHdG. Results. Serum SOD, GSH-Px, and CAT activities in cataract group were significantly decreased as compared to the control subjects (P<0.05. The levels of MDA, 4-HNE, and CD in cataract patients were significantly higher than those in the control subjects (P<0.05, P<0.01. Cataract patients had higher levels of 8-OHdG, AOPP, and PC with respect to the comparative group of normal subjects (P<0.01. And there was no statistical significance in concentration of antioxidative enzymes and oxidative stress products in patients with different subtype cataract. Conclusions. Oxidative stress is an important risk factor in the development of age-related cataract, and augmentation of the antioxidant defence systems may be of benefit to prevent or delay cataractogenesis.

  12. Connectedness of land use, nutrients, primary production, and fish assemblages in oxbow lakes

    Science.gov (United States)

    Miranda, Leandro E.; Andrews, Caroline S.; Kroger, Robert

    2013-01-01

    We explored the strength of connectedness among hierarchical system components associated with oxbow lakes in the alluvial valley of the Lower Mississippi River. Specifically, we examined the degree of canonical correlation between land use (agriculture and forests), lake morphometry (depth and size), nutrients (total nitrogen and total phosphorus), primary production (chlorophyll-a), and various fish assemblage descriptors. Watershed (p < 0.01) and riparian (p = 0.02) land use, and lake depth (p = 0.05) but not size (p = 0.28), were associated with nutrient concentrations. In turn, nutrients were associated with primary production (p < 0.01), and primary production was associated with sunfish (Centrarchidae) assemblages (p < 0.01) and fish biodiversity (p = 0.08), but not with those of other taxa and functional guilds. Multiple chemical and biological components of oxbow lake ecosystems are connected to landscape characteristics such as land use and lake depth. Therefore, a top-down hierarchical approach can be useful in developing management and conservation plans for oxbow lakes in a region impacted by widespread landscape changes due to agriculture.

  13. Lipid and cholesterol oxidation, color changes, and volatile compounds production in irradiated raw pork batters with different fat content

    International Nuclear Information System (INIS)

    Jo, Cheo Run; Byun, Myung Woo

    2000-01-01

    An emulsion-type product was prepared to determine the effect of irradiation on lipid and cholesterol oxidation, color change, and volatile production in raw pork with different fat content. Lipid oxidation increased with an increase in fat content or irradiation dose. Irradiated batters had higher cholesterol oxides than did non-irradiated batters, and the major cholesterol oxides formed in irradiated pork batters were 7α- and 7β- hydroxycholesterol. Hunter color a- and b-values of raw pork batters were decreased by irradiation regardless of fat content. Irradiation significantly increased the amount of volatile compounds. Although lipid oxidation of high fat products (10 and 15% fat) was higher than that of low fat products (4%), high fat products did not always produce greater amount of volatile compounds in raw pork batters. In summary, irradiation increased lipid and cholesterol oxidation, and volatile compounds production, and had detrimental effects on the color of raw pork batter under aerobic conditions

  14. Metal-free oxidative olefination of primary amines with benzylic C-H bonds through direct deamination and C-H bond activation.

    Science.gov (United States)

    Gong, Liang; Xing, Li-Juan; Xu, Tong; Zhu, Xue-Ping; Zhou, Wen; Kang, Ning; Wang, Bin

    2014-09-14

    An oxidative olefination reaction between aliphatic primary amines and benzylic sp(3) C-H bonds has been achieved using N-bromosuccinimide as catalyst and tert-butyl hydroperoxide as oxidant. The olefination proceeds under mild metal-free conditions through direct deamination and benzylic C-H bond activation, and provides easy access to biologically active 2-styrylquinolines with (E)-configuration.

  15. A Bioinspired Catalytic Aerobic Oxidative C–H Functionalization of Primary Aliphatic Amines: Synthesis of 1,2-Disubstituted Benzimidazoles

    Science.gov (United States)

    Nguyen, Khac Minh Huy; Largeron, Martine

    2015-01-01

    Aerobic oxidative C–H functionalization of primary aliphatic amines has been accomplished with a biomimetic cooperative catalytic system to furnish 1,2-disubstituted benzimidazoles that play an important role as drug discovery targets. This one-pot atom-economical multistep process, which proceeds under mild conditions, with ambient air and equimolar amounts of each coupling partner, constitutes a convenient environmentally friendly strategy to functionalize non-activated aliphatic amines that remain challenging substrates for non-enzymatic catalytic aerobic systems. PMID:26206475

  16. Biodiesel production using calcium manganese oxide as catalyst and different raw materials

    International Nuclear Information System (INIS)

    Dias, Joana Maia; Conceição Machado Alvim-Ferraz, Maria; Fonseca Almeida, Manuel; Méndez Díaz, José Diego; Sánchez Polo, Manuel; Rivera Utrilla, José

    2013-01-01

    Highlights: ► Biodiesel production using a calcium manganese oxide catalyst was studied. ► The active specie was Ca 0.9 Mn 0.1 O and its deactivation occurred by hydration. ► The studied catalyst presented lower activation temperature than CaO. ► Biodiesel production and quality using different raw materials is reported. ► Compared to the conventional process, biodiesel water content improved. - Abstract: The use of heterogeneous catalysts for biodiesel production aims to simplify the production process as well as to reduce purification costs and related environmental impacts. Calcium manganese oxide was recently identified by the authors as an interesting heterogeneous catalyst for biodiesel production from animal fat; however, the difference between this and other catalysts, the catalyst activation/deactivation mechanisms, its behaviour in the synthesis using different raw materials as well as the impacts of its use on product quality remained unclear. Therefore, the present work: (i) compared biodiesel production using calcium manganese oxide and other catalysts (CaO and NaOH); (ii) studied the reasons leading to activation/deactivation of the heterogeneous catalyst; (iii) analysed biodiesel heterogeneous synthesis using calcium manganese oxide and different raw materials (lard, waste frying oil and a mixture); and (iv) evaluated raw material and catalyst impact on the product quality. Considering the use of different catalysts, the results showed that, after 8 h of reaction, product purity was similar using the different catalysts, being 92.5 wt.% using both NaOH and calcium manganese oxide and 93.8 wt.% using CaO. The active species of the heterogeneous catalysts were CaO, in the case of calcinated calcium carbonate, and Ca 0.9 Mn 0.1 O, in the case of calcinated calcium manganese oxide. Because the deactivating species were different for both catalysts, the calcium manganese oxide required lower activation temperature, which should be an advantage

  17. The degradation of lining of rotary furnaces in the production of zinc oxide

    OpenAIRE

    Natália Luptáková; Evgeniy Anisimov; Františka Pešlová

    2014-01-01

    This paper is closely connected with the complex problem of degradation relating to the refractories of rotary furnace linings in the production of zinc oxide. Zinc oxide can be produced by variety of ways, but the most common method of production which is used in Europe is indirect, i.e. pyrolytic combustion of zinc. This method is also called "French process" of manufacturing ZnO. But this mentioned method of preparation leads to the creation of the enormous amount of zinc slag including ch...

  18. The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters

    Science.gov (United States)

    2016-01-04

    AFRL-AFOSR-VA-TR-2016-0075 The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters KIT BOWEN JOHNS HOPKINS UNIV BALTIMORE MD...2. REPORT TYPE Final Performance 3. DATES COVERED (From - To) 30-09-2014 to 29-09-2015 4. TITLE AND SUBTITLE The Oxidation Products of Aluminum ...Hydride and Boron Aluminum Hydride Clusters 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-14-1-0324 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) KIT

  19. Photoinduced Coherent Spin Fluctuation in Primary Dynamics of Insulator to Metal Transition in Perovskite Cobalt Oxide

    Directory of Open Access Journals (Sweden)

    Arima T.

    2013-03-01

    Full Text Available Coherent spin fluctuation was detected in the photoinduced Mott insulator-metal transition in perovskite cobalt oxide by using 3 optical-cycle infrared pulse. Such coherent spin fluctuation is driven by the perovskite distortion changing orbital gap.

  20. The Effect of Improving Primary Care Depression Management on Employee Absenteeism and Productivity A Randomized Trial

    Science.gov (United States)

    Rost, Kathryn; Smith, Jeffrey L.; Dickinson, Miriam

    2005-01-01

    Objective: To test whether an intervention to improve primary care depression management significantly improves productivity at work and absenteeism over 2 years. Setting and Subjects: Twelve community primary care practices recruiting depressed primary care patients identified in a previsit screening. Research Design: Practices were stratified by depression treatment patterns before randomization to enhanced or usual care. After delivering brief training, enhanced care clinicians provided improved depression management over 24 months. The research team evaluated productivity and absenteeism at baseline, 6, 12, 18, and 24 months in 326 patients who reported full-or part-time work at one or more completed waves. Results: Employed patients in the enhanced care condition reported 6.1% greater productivity and 22.8% less absenteeism over 2 years. Consistent with its impact on depression severity and emotional role functioning, intervention effects were more observable in consistently employed subjects where the intervention improved productivity by 8.2% over 2 years at an estimated annual value of $1982 per depressed full-time equivalent and reduced absenteeism by 28.4% or 12.3 days over 2 years at an estimated annual value of $619 per depressed full-time equivalent. Conclusions: This trial, which is the first to our knowledge to demonstrate that improving the quality of care for any chronic disease has positive consequences for productivity and absenteeism, encourages formal cost-benefit research to assess the potential return-on-investment employers of stable workforces can realize from using their purchasing power to encourage better depression treatment for their employees. PMID:15550800

  1. The effect of improving primary care depression management on employee absenteeism and productivity. A randomized trial.

    Science.gov (United States)

    Rost, Kathryn; Smith, Jeffrey L; Dickinson, Miriam

    2004-12-01

    To test whether an intervention to improve primary care depression management significantly improves productivity at work and absenteeism over 2 years. Twelve community primary care practices recruiting depressed primary care patients identified in a previsit screening. Practices were stratified by depression treatment patterns before randomization to enhanced or usual care. After delivering brief training, enhanced care clinicians provided improved depression management over 24 months. The research team evaluated productivity and absenteeism at baseline, 6, 12, 18, and 24 months in 326 patients who reported full-or part-time work at one or more completed waves. Employed patients in the enhanced care condition reported 6.1% greater productivity and 22.8% less absenteeism over 2 years. Consistent with its impact on depression severity and emotional role functioning, intervention effects were more observable in consistently employed subjects where the intervention improved productivity by 8.2% over 2 years at an estimated annual value of US 1982 dollars per depressed full-time equivalent and reduced absenteeism by 28.4% or 12.3 days over 2 years at an estimated annual value of US 619 dollars per depressed full-time equivalent. This trial, which is the first to our knowledge to demonstrate that improving the quality of care for any chronic disease has positive consequences for productivity and absenteeism, encourages formal cost-benefit research to assess the potential return-on-investment employers of stable workforces can realize from using their purchasing power to encourage better depression treatment for their employees.

  2. Modelling and numerical simulation of the corrosion product transport in the pressurised water reactor primary circuit

    International Nuclear Information System (INIS)

    Marchetto, C.

    2002-05-01

    During operation of pressurised water reactor, corrosion of the primary circuit alloys leads to the release of metallic species such as iron, nickel and cobalt in the primary fluid. These corrosion products are implicated in different transport phenomena and are activated in the reactor core where they are submitted to neutron flux. The radioactive corrosion products are afterwards present in the out of flux parts of primary circuit where they generate a radiation field. The first part of this study deals with the modelling of the corrosion: product transport phenomena. In particular, considering the current state of the art, corrosion and release mechanisms are described empirically, which allows to take into account the material surface properties. New mass balance equations describing the corrosion product behaviour are thus obtained. The numerical resolution of these equations is implemented in the second part of this work. In order to obtain large time steps, we choose an implicit time scheme. The associated system is linearized from the Newton method and is solved by a preconditioned GMRES method. Moreover, a time step auto-adaptive management based on Newton iterations is performed. Consequently, an efficient resolution has been implemented, allowing to describe not only the quasi-steady evolutions but also the fast transients. In a last step, numerical simulations are carried out in order to validate the new corrosion product transport modelling and to illustrate the capabilities of this modelling. Notably, the numerical results obtained indicate that the code allows to restore the on-site observations underlining the influence of material surface properties on reactor contamination. (author)

  3. Oxidant production and SOD1 protein expression in single skeletal myofibers from Down syndrome mice

    Directory of Open Access Journals (Sweden)

    Patrick M. Cowley

    2017-10-01

    Full Text Available Down syndrome (DS is a genetic condition caused by the triplication of chromosome 21. Persons with DS exhibit pronounced muscle weakness, which also occurs in the Ts65Dn mouse model of DS. Oxidative stress is thought to be an underlying factor in the development of DS-related pathologies including muscle dysfunction. High-levels of oxidative stress have been attributed to triplication and elevated expression of superoxide dismutase 1 (SOD1; a gene located on chromosome 21. The elevated expression of SOD1 is postulated to increase production of hydrogen peroxide and cause oxidative injury and cell death. However, it is unknown whether SOD1 protein expression is associated with greater oxidant production in skeletal muscle from Ts65Dn mice. Thus, our objective was to assess levels of SOD1 expression and oxidant production in skeletal myofibers from the flexor digitorum brevis obtained from Ts65Dn and control mice. Measurements of oxidant production were obtained from myofibers loaded with 2′,7′-dichlorodihydrofluorescein diacetate (DCFH2-DA in the basal state and following 15 min of stimulated unloaded contraction. Ts65Dn myofibers exhibited a significant decrease in basal DCF emissions (p 0.05. Myofibers from Ts65Dn mice tended to be smaller and myonuclear domain was lower (p < 0.05. In summary, myofibers from Ts65Dn mice exhibited decreased basal DCF emissions that were coupled with elevated protein expression of SOD1. Stimulated contraction in isolated myofibers did not affect DCF emissions in either group. These findings suggest the skeletal muscle dysfunction in the adult Ts65Dn mouse is not associated with skeletal muscle oxidative stress.

  4. Short exposure to acetylene to distinguish between nitrifier and denitrifier nitrous oxide production in soil and sediment samples

    OpenAIRE

    Kester, R.A.; Boer, W. de; Laanbroek, H.J.

    1996-01-01

    The contribution of nitrifiers and denitrifiers to the nitrous oxide production in slurries of calcareous silt loam and river bank sediment at different oxygen concentrations was determined using acetylene as nitrification inhibitor. The addition of 10 Pa acetylene resulted in inhibition of nitrous oxide production at oxic conditions, but strongly enhanced the nitrous oxide production at oxygen-poor and anoxic conditions. Inhibition of nitrification by short exposure (1 to 24 h) to high conce...

  5. Clinical and radiographic evaluation of zinc oxide eugenol and metapex in root canal treatment of primary teeth

    Directory of Open Access Journals (Sweden)

    S Gupta

    2011-01-01

    Full Text Available Objectives: The aim of this study was to evaluate clinically and radiographically zinc oxide eugenol (ZOE and Metapex as root canal filling material in primary teeth. Materials and Methods: Forty-two necrotic primary teeth in two groups of children in the age group of 4−7 years were obturated with ZOE and Metapex and were followed up clinically and radiographically for a period of 6 months postoperatively. Results: The overall success rates of ZOE and Metapex were 85.71% and 90.48%, respectively. Conclusion: Both ZOE and Metapex gave encouraging results; however, Metapex can be used more safely whenever there is a doubt about the patient′s return for follow-up.

  6. Fission product plateout and liftoff in the MHTGR primary system: A review

    International Nuclear Information System (INIS)

    Wichner, R.P.

    1991-04-01

    A review is presented of the technical basis for predicting radioactivity release resulting from depressurization of an MHTGR primary system. Consideration is restricted to so called dry events with no involvement of the steam system. The various types of deposition mechanisms effective for iodine, cesium, strontium, and silver are discussed in terms of their chemical characteristics and the nature of the materials in the primary system. Emphasis is given to iodine behavior, including means for estimating the quantity available for release, the types of plateout locations in the primary system, and the effect of dust on distribution and release. The behavior of fission products cesium, strontium, and silver in such accidents is presented qualitatively. A major part of the review deals with expected dust levels, types, and transport. Available information on the level and nature of dust in the HTGR primary system is reviewed. A summary is presented of dust deposition and liftoff mechanisms. It was concluded that recent approaches to dust liftoff modeling, based on turbulent burst concepts for removal from surfaces, probably offer advantages over the current shear ratio approach. This study concludes that iodine releases from dry depressurization events are likely to be extremely low, on the order of millicuries, due to a predictably low degree of chemical desorption, a low degree of dust liftoff, and a low involvement of iodine with dust. It was also concluded that deposition mechanisms controlling the distribution of fission product material in the primary system, and hence also controlling the degree of liftoff, depend strongly on the chemical nature of the individual elements. Therefore contrary to the current practice, both plateout and liftoff models should reflect those unique chemical and physical properties. 56 refs., 16 figs., 23 tabs

  7. Ochratoxin A: induction of (oxidative) DNA damage, cytotoxicity and apoptosis in mammalian cell lines and primary cells

    International Nuclear Information System (INIS)

    Kamp, Hennicke G.; Eisenbrand, Gerhard; Schlatter, Josef; Wuerth, Kirsten; Janzowski, Christine

    2005-01-01

    Ochratoxin A (OTA) is a nephrotoxic/-carcinogenic mycotoxin, produced by several Aspergillus- and Penicillium-strains. Humans are exposed to OTA via food contamination, a causal relationship of OTA to human endemic Balkan nephropathy is still under debate. Since DNA-adducts of OTA or its metabolites could not be identified unambiguously, its carcinogenic effectiveness might be related to secondary effects, such as oxidative cell damage or cell proliferation. In this study, OTA mediated induction of (oxidative) DNA damage, cytotoxicity (necrosis, growth inhibition, apoptosis) and modulation of glutathione were investigated in cell lines (V79, CV-1) and primary rat kidney cells. After 24 h incubation, viability of V79 cells was strongly decreased by OTA concentrations >2.5 μmol/L, whereas CV-1 cells were clearly less sensitive. Strong growth inhibition occurred in both cell lines (IC 50 ∼2 μmol/L). Apoptosis, detected with an immunochemical test and with flow cytometry, was induced by >1 μmol/L OTA. Oxidative DNA damage, detected by comet assay after additional treatment with repair enzymes, was induced in all cell systems already at five-fold lower concentrations. Glutathione in CV-1 cells was depleted after 1 h incubation (>100 μmol/L). In contrast, an increase was measured after 24 h incubation (>0.5 μmol/L). In conclusion, OTA induces oxidative DNA damage at low, not yet cytotoxic concentrations. Oxidative DNA damage might initiate cell transformation eventually in connection with proliferative response following cytotoxic cell death. Both events might represent pivotal factors in the chain of cellular events leading into nephro-carcinogenicity of OTA

  8. Retrieval of daily gross primary production over Europe and Africa from an ensemble of SEVIRI/MSG products

    Science.gov (United States)

    Martínez, B.; Sanchez-Ruiz, S.; Gilabert, M. A.; Moreno, A.; Campos-Taberner, M.; García-Haro, F. J.; Trigo, I. F.; Aurela, M.; Brümmer, C.; Carrara, A.; De Ligne, A.; Gianelle, D.; Grünwald, T.; Limousin, J. M.; Lohila, A.; Mammarella, I.; Sottocornola, M.; Steinbrecher, R.; Tagesson, T.

    2018-03-01

    The main goal of this paper is to derive a method for a daily gross primary production (GPP) product over Europe and Africa taking the full advantage of the SEVIRI/MSG satellite products from the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) sensors delivered from the Satellite Application Facility for Land Surface Analysis (LSA SAF) system. Special attention is paid to model the daily GPP response from an optimized Montheith's light use efficiency model under dry conditions by controlling water shortage limitations from the actual evapotranspiration and the potential evapotranspiration (PET). The PET was parameterized using the mean daily air temperature at 2 m (Ta) from ERA-Interim data. The GPP product (MSG GPP) was produced for 2012 and assessed by direct site-level comparison with GPP from eddy covariance data (EC GPP). MSG GPP presents relative bias errors lower than 40% for the most forest vegetation types with a high agreement (r > 0.7) when compared with EC GPP. For drylands, MSG GPP reproduces the seasonal variations related to water limitation in a good agreement with site level GPP estimates (RMSE = 2.11 g m-2 day-1; MBE = -0.63 g m-2 day-1), especially for the dry season. A consistency analysis against other GPP satellite products (MOD17A2 and FLUXCOM) reveals a high consistency among products (RMSD Africa. The major GPP disagreement arises over moist biomes in central Africa (RMSD > 3.0 g m-2 day-1) and over dry biomes with MSG GPP estimates lower than FLUXCOM (MBD up to -3.0 g m-2 day-1). This newly derived product has the potential for analysing spatial patterns and temporal dynamics of GPP at the MSG spatial resolutions on a daily basis allowing to better capture the GPP dynamics and magnitude.

  9. Distortion product otoacoustic emissions: comparison of sequential vs. simultaneous presentation of primary tones.

    Science.gov (United States)

    Kumar, U Ajith; Maruthy, Sandeep; Chandrakant, Vishwakarma

    2009-03-01

    Distortion product otoacoustic emissions are one form of evoked otoacoustic emissions. DPOAEs provide the frequency specific information about the hearing status in mid and high frequency regions. But in most screening protocols TEOAEs are preferred as it requires less time compared to DPOAE. This is because, in DPOAE each stimulus is presented one after the other and responses are analyzed. Grason and Stadler Incorporation 60 (GSI-60) offer simultaneous presentation of four sets of primary tones at a time and checks for the DPOAE. In this mode of presentation, all the pairs are presented at a time and following that response is extracted separately whereas, in sequential mode primaries are presented in orderly fashion one after the other. In this article simultaneous and sequential protocols were used to compare the Distortion product otoacoustic emission amplitude, noise floor and administration time in individuals with normal hearing and mild sensori-neural (SN) hearing loss. In simultaneous protocols four sets of primary tones (i.e. 8 tones) were presented together whereas, in sequential presentation mode one set of primary tones was presented each time. Simultaneous protocol was completed in less than half the time required for the completion of sequential protocol. Two techniques yielded similar results at frequencies above 1000 Hz only in normal hearing group. In SN hearing loss group simultaneous presentation yielded signifi cantly higher noise floors and distortion product amplitudes. This result challenges the use of simultaneous presentation technique in neonatal hearing screening programmes and on other pathologies. This discrepancy between two protocols may be due to some changes in biomechanical process in the cochlear and/or due to higher distortion/noise produced by the system during the simultaneous presentation mode.

  10. Primary souring: A novel bacteria-free method for sour beer production.

    Science.gov (United States)

    Osburn, Kara; Amaral, Justin; Metcalf, Sara R; Nickens, David M; Rogers, Cody M; Sausen, Christopher; Caputo, Robert; Miller, Justin; Li, Hongde; Tennessen, Jason M; Bochman, Matthew L

    2018-04-01

    In the beverage fermentation industry, especially at the craft or micro level, there is a movement to incorporate as many local ingredients as possible to both capture terroir and stimulate local economies. In the case of craft beer, this has traditionally only encompassed locally sourced barley, hops, and other agricultural adjuncts. The identification and use of novel yeasts in brewing lags behind. We sought to bridge this gap by bio-prospecting for wild yeasts, with a focus on the American Midwest. We isolated 284 different strains from 54 species of yeast and have begun to determine their fermentation characteristics. During this work, we found several isolates of five species that produce lactic acid and ethanol during wort fermentation: Hanseniaspora vineae, Lachancea fermentati, Lachancea thermotolerans, Schizosaccharomyces japonicus, and Wickerhamomyces anomalus. Tested representatives of these species yielded excellent attenuation, lactic acid production, and sensory characteristics, positioning them as viable alternatives to lactic acid bacteria (LAB) for the production of sour beers. Indeed, we suggest a new LAB-free paradigm for sour beer production that we term "primary souring" because the lactic acid production and resultant pH decrease occurs during primary fermentation, as opposed to kettle souring or souring via mixed culture fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore Emiliania huxleyi

    Science.gov (United States)

    Borchard, C.; Engel, A.

    2015-02-01

    Extracellular release (ER) by phytoplankton is the major source of fresh dissolved organic carbon (DOC) in marine ecosystems and accompanies primary production during all growth phases. Little is known, so far, on size and composition of released molecules, and to which extent ER occurs passively, by leakage, or actively, by exudation. Here, we report on ER by the widespread and bloom-forming coccolithophore Emiliania huxleyi grown under steady-state conditions in phosphorus-controlled chemostats (N:P = 29, growth rate of μ = 0.2 d-1) at present-day and high-CO2 concentrations. 14C incubations were performed to determine primary production (PP), comprised of particulate (PO14C) and dissolved organic carbon (DO14C). Concentration and composition of particulate combined carbohydrates (pCCHO) and high-molecular-weight (>1 kDa, HMW) dissolved combined carbohydrates (dCCHO) were determined by ion chromatography. Information on size distribution of ER products was obtained by investigating distinct size classes (10 kDa was significantly different, with a higher mol% of arabinose. The mol% of acidic sugars increased and that of glucose decreased with increasing size of HMW-dCCHO. We conclude that larger polysaccharides follow different production and release pathways than smaller molecules, potentially serving distinct ecological and biogeochemical functions.

  12. Satellite remote sensing for estimating leaf area index, FPAR and primary production. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Boresjoe Bronge, Laine [SwedPower AB, Stockholm (Sweden)

    2004-03-01

    Land vegetation is a critical component of several biogeochemical cycles that have become the focus of concerted international research effort. Most ecosystem productivity models, carbon budget models, and global models of climate, hydrology and biogeochemistry require vegetation parameters to calculate land surface photosynthesis, evapotranspiration and net primary production. Therefore, accurate estimates of vegetation parameters are increasingly important in the carbon cycle, the energy balance and in environmental impact assessment studies. The possibility of quantitatively estimating vegetation parameters of importance in this context using satellite data has been explored by numerous papers dealing with the subject. This report gives a summary of the present status and applicability of satellite remote sensing for estimating vegetation productivity by using vegetation index for calculating leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR). Some possible approaches for use of satellite data for estimating LAI, FPAR and net primary production (NPP) on a local scale are suggested. Recommendations for continued work in the Forsmark and Oskarshamn investigation areas, where vegetation data and NDVI-images based on satellite data have been produced, are also given.

  13. Satellite remote sensing for estimating leaf area index, FPAR and primary production. A literature review

    International Nuclear Information System (INIS)

    Boresjoe Bronge, Laine

    2004-03-01

    Land vegetation is a critical component of several biogeochemical cycles that have become the focus of concerted international research effort. Most ecosystem productivity models, carbon budget models, and global models of climate, hydrology and biogeochemistry require vegetation parameters to calculate land surface photosynthesis, evapotranspiration and net primary production. Therefore, accurate estimates of vegetation parameters are increasingly important in the carbon cycle, the energy balance and in environmental impact assessment studies. The possibility of quantitatively estimating vegetation parameters of importance in this context using satellite data has been explored by numerous papers dealing with the subject. This report gives a summary of the present status and applicability of satellite remote sensing for estimating vegetation productivity by using vegetation index for calculating leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR). Some possible approaches for use of satellite data for estimating LAI, FPAR and net primary production (NPP) on a local scale are suggested. Recommendations for continued work in the Forsmark and Oskarshamn investigation areas, where vegetation data and NDVI-images based on satellite data have been produced, are also given

  14. Durable solid oxide electrolysis cells for hydrogen production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang

    2014-01-01

    production is required for promoting commercialization of the SOEC technology. In this work, we report a recent 4400 hours test of a state-of-the-art Ni-YSZ electrode supported SOEC cell. The cell consists of a Ni-YSZ (YSZ: yttria stabilized zirconia) support and active fuel electrode, an YSZ electrolyte...... that except for the first 250 hours fast initial degradation, for the rest of the testing period, the cell showed rather stable performance with an moderate degradation rate of around 25 mV/1000 h. The electrochemical impedance spectra show that both serial resistance and polarization resistance of the cell...... and changing of porosity inside the active layer. The degree of these microstructural changes becomes less and less severe along the hydrogen-steam flow path. The present test results show that this type of cell can be used for early demonstration electrolysis at 1A/cm2. Future work should be focus on reducing...

  15. A multi-sites analysis on the ozone effects on Gross Primary Production of European forests

    Energy Technology Data Exchange (ETDEWEB)

    Proietti, C. [Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome (Italy); Anav, A. [Italian National Agency for New Technologies, Energy and the Environment (ENEA), C.R. Casaccia, Via Anguillarese 301, 00123 S. Maria di Galeria, Rome (Italy); University of Exeter, College of Engineering, Mathematics and Physical Sciences, Exeter (United Kingdom); De Marco, A. [Italian National Agency for New Technologies, Energy and the Environment (ENEA), C.R. Casaccia, Via Anguillarese 301, 00123 S. Maria di Galeria, Rome (Italy); Sicard, P. [ACRI-HE, 260 route du Pin Montard BP234, 06904 Sophia Antipolis-cedex (France); Vitale, M., E-mail: marcello.vitale@uniroma1.it [Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome (Italy)

    2016-06-15

    Ozone (O{sub 3}) is both a greenhouse gas and a secondary air pollutant causing adverse impacts on forests ecosystems at different scales, from cellular to ecosystem level. Specifically, the phytotoxic nature of O{sub 3} can impair CO{sub 2} assimilation that, in turn affects forest productivity. This study aims to evaluate the effects of tropospheric O{sub 3} on Gross Primary Production (GPP) at 37 European forest sites during the time period 2000–2010. Due to the lack of carbon assimilation data at O{sub 3} monitoring stations (and vice-versa) this study makes a first attempt to combine high resolution MODIS Gross Primary Production (GPP) estimates and O{sub 3} measurement data. Partial Correlations, Anomalies Analysis and the Random Forests Analysis (RFA) were used to quantify the effects of tropospheric O{sub 3} concentration and its uptake on GPP and to evaluate the most important factors affecting inter-annual GPP changes. Our results showed, along a North-West/South-East European transect, a negative impact of O{sub 3} on GPP ranging from 0.4% to 30%, although a key role of meteorological parameters respect to pollutant variables in affecting GPP was found. In particular, meteorological parameters, namely air temperature (T), soil water content (SWC) and relative humidity (RH) are the most important predictors at 81% of test sites. Moreover, it is interesting to highlight a key role of SWC in the Mediterranean areas (Spanish, Italian and French test sites) confirming that, soil moisture and soil water availability affect vegetation growth and photosynthesis especially in arid or semi-arid ecosystems such as the Mediterranean climate regions. Considering the pivotal role of GPP in the global carbon balance and the O{sub 3} ability to reduce primary productivity of the forests, this study can help in assessing the O{sub 3} impacts on ecosystem services, including wood production and carbon sequestration. - Highlights: • Assessment of the surface O{sub 3

  16. The Puzzle of HCN in Comets: Is it both a Product and a Primary Species?

    Science.gov (United States)

    Mumma, Michael J.; Bonev, Boncho P.; Charnley, Steven B.; Cordiner, Martin A.; DiSanti, Michael A.; Gibb, Erika L.; Magee-Sauer, Karen; Paganini, Lucas; Villanueva, Geronimo L.

    2014-11-01

    Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: 1. HCN is often used as a proxy for water when the dominant species (H2O) is not available for simultaneous measurement, as at radio wavelengths. 2. HCN is one of the few volatile carriers of nitrogen accessible to remote sensing. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. 3. The stereoisomer HNC is now confirmed as a product species. Could reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? 4. The production rate for CN greatly exceeds that of HCN in some comets, demonstrating the presence of another (more important) precursor of CN. Several puzzling lines of evidence raise issues about the origin of HCN: a. The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets - in others the infrared rate exceeds the radio rate substantially. b. With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H2O, CH3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). c. The nucleus-centered rotational temperatures measured for H2O and other species (C2H6, CH3OH) usually agree within error, but those for HCN are often slightly smaller. d. In comet ISON, ALMA maps of HCN and the dust continuum show a slight displacement 80 km) in the centroids. We will

  17. Small phytoplankton contribution to the standing stocks and the total primary production in the Amundsen Sea

    Directory of Open Access Journals (Sweden)

    S. H. Lee

    2017-08-01

    Full Text Available Small phytoplankton are anticipated to be more important in a recently warming and freshening ocean condition. However, little information on the contribution of small phytoplankton to overall phytoplankton production is currently available in the Amundsen Sea. To determine the contributions of small phytoplankton to total biomass and primary production, carbon and nitrogen uptake rates of total and small phytoplankton were obtained from 12 productivity stations in the Amundsen Sea. The daily carbon uptake rates of total phytoplankton averaged in this study were 0.42 g C m−2 d−1 (SD  =  ± 0.30 g C m−2 d−1 and 0.84 g C m−2 d−1 (SD  =  ± 0.18 g C m−2 d−1 for non-polynya and polynya regions, respectively, whereas the daily total nitrogen (nitrate and ammonium uptake rates were 0.12 g N m−2 d−1 (SD  =  ± 0.09 g N m−2 d−1 and 0.21 g N m−2 d−1 (SD  =  ± 0.11 g N m−2 d−1, respectively, for non-polynya and polynya regions, all of which were within the ranges reported previously. Small phytoplankton contributed 26.9 and 27.7 % to the total carbon and nitrogen uptake rates of phytoplankton in this study, respectively, which were relatively higher than the chlorophyll a contribution (19.4 % of small phytoplankton. For a comparison of different regions, the contributions for chlorophyll a concentration and primary production of small phytoplankton averaged from all the non-polynya stations were 42.4 and 50.8 %, which were significantly higher than those (7.9 and 14.9 %, respectively in the polynya region. A strong negative correlation (r2 = 0. 790, p<0. 05 was found between the contributions of small phytoplankton and the total daily primary production of phytoplankton in this study. This finding implies that daily primary production decreases as small phytoplankton contribution increases, which is

  18. Large-scale Modeling of Nitrous Oxide Production: Issues of Representing Spatial Heterogeneity

    Science.gov (United States)

    Morris, C. K.; Knighton, J.

    2017-12-01

    Nitrous oxide is produced from the biological processes of nitrification and denitrification in terrestrial environments and contributes to the greenhouse effect that warms Earth's climate. Large scale modeling can be used to determine how global rate of nitrous oxide production and consumption will shift under future climates. However, accurate modeling of nitrification and denitrification is made difficult by highly parameterized, nonlinear equations. Here we show that the representation of spatial heterogeneity in inputs, specifically soil moisture, causes inaccuracies in estimating the average nitrous oxide production in soils. We demonstrate that when soil moisture is averaged from a spatially heterogeneous surface, net nitrous oxide production is under predicted. We apply this general result in a test of a widely-used global land surface model, the Community Land Model v4.5. The challenges presented by nonlinear controls on nitrous oxide are highlighted here to provide a wider context to the problem of extraordinary denitrification losses in CLM. We hope that these findings will inform future researchers on the possibilities for model improvement of the global nitrogen cycle.

  19. Epiphytes modulate Posidonia oceanica photosynthetic production, energetic balance, antioxidant mechanisms and oxidative damage

    Directory of Open Access Journals (Sweden)

    Monya Mendes Costa

    2015-12-01

    Full Text Available Epiphytes impose physical barriers to light penetration into seagrass leaves causing shading, which may decrease the production of oxygen reactive species (ROS, but also constitute a physical aggression that may trigger the production of ROS, leading to oxidative damage. Here we investigate the effects of epiphytes on Posidonia oceanica under both interactive perspectives, light attenuation and oxidative stress. Specifically the role of epiphytes in net photosynthesis, chlorophyll a and b, photoprotection (Violaxanthin+Anteraxanthin+Zeaxanthin cycle, soluble sugar and starch contents, enzymatic (ascorbate peroxidase (APX and dehydroascorbate reductase (DHAR and global (trolox equivalent antioxidant capacity (TEAC and oxygen radical antioxidant capacity (ORAC antioxidant responses, phenolics and oxidative damage (malondialdehyde are tested. Leaves with epiphytes showed higher chlorophyll b and lower content in VAZ cycle carotenoids. Epiphyte shading was the probable reason for the lower VAZ de-epoxidation-ratio of leaves with epiphytes. In spite of being shaded, leaves with epiphytes showed higher antioxidant levels, indicating that epiphytes trigger the production of ROS. Both ORAC and TEAC and also APX and DHAR activities were higher in leaves with epiphytes, indicating that this response was related with its presence. Malondialdehyde concentrations also suggest oxidative damage caused by epiphytes. We conclude that the epiphyte load causes oxidative stress in P. oceanica and the mechanisms to scavenge ROS were not completely effective to avoid cell damage.

  20. Study on the production mechanism of Co-60 in the primary loop of HTR-10

    International Nuclear Information System (INIS)

    Wang Shouang; Xie Feng; Li Hong; Cao Jianzhu; Li Fu; Wei Liqiang

    2015-01-01

    Co-60 is an activated metallic erosion product, which is very important for waste management and decommissioning work of pressurized water reactor (PWR) power plants. Recent measurement on the samples from the primary loop of HTR-10 indicates the existence of Co-60. In current paper, the preliminary experimental results in HTR-10 will be introduced, and the production mechanism of Co-60 in the pebble bed high temperature gas-cooled reactors will be summarized and compared with that in PWRs and Germany High Temperature Nuclear Reactor (AVR). The further experiments with decomposing the post-irradiation graphite spheres of HTR-10 are put forward, which will promote the further study to testify the production sources of Co-60 and be of great significance in the waste minimization and the decommissioning work of HTR-10. (author)