WorldWideScience

Sample records for carbon 14 target

  1. Carbonate as sputter target material for rapid {sup 14}C AMS

    Energy Technology Data Exchange (ETDEWEB)

    Longworth, Brett E., E-mail: blongworth@whoi.edu [Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Robinson, Laura F. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Roberts, Mark L.; Beaupre, Steven R.; Burke, Andrea [Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Jenkins, William J. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA (United States)

    2013-01-15

    This paper describes a technique for measuring the {sup 14}C content of carbonate samples by producing C{sup -} ions directly in the negative ion sputter source of an accelerator mass spectrometer (AMS) system. This direct analysis of carbonate material eliminates the time and expense of graphite preparation. Powdered carbonate is mixed with titanium powder, loaded into a target cartridge, and compressed. Beam currents for optimally-sized carbonate targets (0.09-0.15 mg C) are typically 10-20% of those produced by optimally-sized graphite targets (0.5-1 mg C). Modern (>0.8 Fm) samples run by this method have standard deviations of 0.009 Fm or less, and near-modern samples run as unknowns agree with values from traditional hydrolysis/graphite to better than 2%. Targets with as little as 0.06 mg carbonate produce useable ion currents and results, albeit with increased error and larger blank. In its current state, direct sputtering is best applied to problems where a large number of analyses with lower precision are required. These applications could include age surveys of deep-sea corals for determination of historic population dynamics, to identify samples that would benefit from high precision analysis, and for growth rate studies of organisms forming carbonate skeletons.

  2. Carbon 14

    International Nuclear Information System (INIS)

    2002-03-01

    Carbon 14 is one of the most abundant radionuclides of natural and artificial origin in the environment. The aim of this conference day organized by the French society of radioprotection (SFRP) was to take stock of our knowledge about this radionuclide (origins, production, measurement, management, effects on health..): state-of-the-art of 14 C metrology; dating use of 14 C; 14 C management and monitoring of the Hague site environment; Electricite de France (EdF) and 14 C; radiological and sanitary impact of 14 C contamination at the Ganagobie site (Haute-Provence, France); metabolism and biological effects of 14 C; 14 C behaviour in the marine environment near Cogema-La Hague plant; distribution of 14 C activities in waters, mud and sediments of the Loire river estuary; dynamical modeling of transfers in the aquatic and terrestrial environment of 14 C released by nuclear power plants in normal operation: human dose calculation using the Calvados model and application to the Loire river; 14 C distribution in continents; modeling of 14 C transfers in the terrestrial environment from atmospheric sources. (J.S.)

  3. Carbon-14 waste management

    International Nuclear Information System (INIS)

    Bush, R.P.; Smith, G.M.; White, I.F

    1984-01-01

    Carbon-14 occurs in nature, but is also formed in nuclear reactors. Because of its long half-life and the biological significance of carbon, releases from nuclear facilities could have a significant radiological impact. Waste management strategies for carbon-14 are therefore of current concern. Carbon-14 is present in a variety of waste streams both at reactors and at reprocessing plants. A reliable picture of the production and release of carbon-14 from various reactor systems has been built up for the purposes of this study. A possible management strategy for carbon-14 might be the reduction of nitrogen impurity levels in core materials, since the activation of 14 N is usually the dominant source of carbon-14. The key problem in carbon-14 management is its retention of off-gas streams, particularly in the dissolver off-gas stream at reprocessing plants. Three alternative trapping processes that convert carbon dioxide into insoluble carbonates have been suggested. The results show that none of the options considered need be rejected on the grounds of potential radiation doses to individuals. All exposures should be as low as reasonably achievable, economic and social factors being taken into account. If, on these grounds, retention and disposal of carbon-14 is found to be beneficial, then, subject to the limitations noted, appropriate retention, immobilization and disposal technologies have been identified

  4. Carbon-14 waste management

    International Nuclear Information System (INIS)

    Bush, R.P.

    1984-01-01

    As part of their research programme on Radioactive Waste Management, the Commission of the European Communities has provided financial support for a detailed study of wastes containing 14 C and the options for their management. The main results of this study are outlined. Carbon-14 is formed by neutron activation reactions in core materials and is therefore present in a variety of waste streams both at reactors and at reprocessing plants. Data on the production and release of 14 C from various reactor systems are presented. A possible management strategy for 14 C might be reduction of 14 N impurity levels in core materials, but only reductions of about a factor of five in arisings could be achieved in this way. The key problem in 14 C management is its retention in off-gas streams, particularly in the dissolver off-gas stream at reprocessing plants. In this stream the nuclide is present as carbon dioxide and is extensively isotopically diluted by the carbon dioxide content of the air. Processes for trapping 14 C from these off-gases must be integrated with the other processes in the overall off-gas treatment system, and should provide for conversion to a stable solid compound of carbon, suitable for subsequent immobilization and disposal. Three trapping processes that convert carbon dioxide into insoluble carbonates can be identified: the double alkali (NaOH/Ca(OH) 2 ) process, the direct calcium hydroxide slurry process, and the barium ocathydrate gas/solid process. Calcium or barium carbonates, produced in the above processes, could probably be incorporated into satisfactory immobilized waste forms. However, the stability of such waste forms to prolonged irradiation and to leaching remains to be investigated. (author)

  5. Carbon-14 Graphitization Chemistry

    Science.gov (United States)

    Miller, James; Collon, Philippe; Laverne, Jay

    2014-09-01

    Accelerator Mass Spectrometry (AMS) is a process that allows for the analysis of mass of certain materials. It is a powerful process because it results in the ability to separate rare isotopes with very low abundances from a large background, which was previously impossible. Another advantage of AMS is that it only requires very small amounts of material for measurements. An important application of this process is radiocarbon dating because the rare 14C isotopes can be separated from the stable 14N background that is 10 to 13 orders of magnitude larger, and only small amounts of the old and fragile organic samples are necessary for measurement. Our group focuses on this radiocarbon dating through AMS. When performing AMS, the sample needs to be loaded into a cathode at the back of an ion source in order to produce a beam from the material to be analyzed. For carbon samples, the material must first be converted into graphite in order to be loaded into the cathode. My role in the group is to convert the organic substances into graphite. In order to graphitize the samples, a sample is first combusted to form carbon dioxide gas and then purified and reduced into the graphite form. After a couple weeks of research and with the help of various Physics professors, I developed a plan and began to construct the setup necessary to perform the graphitization. Once the apparatus is fully completed, the carbon samples will be graphitized and loaded into the AMS machine for analysis.

  6. Compilation of carbon-14 data

    International Nuclear Information System (INIS)

    Paasch, R.A.

    1985-01-01

    A review and critical analysis was made of the original sources of carbon-14 in the graphite moderator and reflector zones of the eight Hanford production reactors, the present physical and chemical state of the carbon-14, pathways (other than direct combustion) by which the carbon-14 could be released to the biosphere, and the maximum rate at which it might be released under circumstances which idealistically favor the release. Areas of uncertainty are noted and recommendations are made for obtaining additional data in three areas: (1) release rate of carbon-14 from irradiated graphite saturated with aerated water; (2) characterization of carbon-14 deposited outside the moderator and reflector zones; and (3) corrosion/release rate of carbon-14 from irradiated steel and aluminum alloys

  7. Apportioning bacterial carbon source utilization in soil using 14 C isotope analysis of FISH-targeted bacterial populations sorted by fluorescence activated cell sorting (FACS): 14 C-FISH-FACS.

    Science.gov (United States)

    Gougoulias, Christos; Meade, Andrew; Shaw, Liz J

    2018-02-19

    An unresolved need in microbial ecology is methodology to enable quantitative analysis of in situ microbial substrate carbon use at the population level. Here, we evaluated if a novel combination of radiocarbon-labelled substrate tracing, fluorescence in situ hybridisation (FISH) and fluorescence-activated cell sorting (FACS) to sort the FISH-targeted population for quantification of incorporated radioactivity ( 14 C-FISH-FACS) can address this need. Our test scenario used FISH probe PSE1284 targeting Pseudomonas spp. (and some Burkholderia spp.) and salicylic acid added to rhizosphere soil. We examined salicylic acid- 14 C fate (mineralized, cell-incorporated, extractable and non-extractable) and mass balance (0-24 h) and show that the PSE1284 population captured ∼ 50% of the Nycodenz extracted biomass 14 C. Analysis of the taxonomic distribution of the salicylic acid biodegradation trait suggested that PSE1284 population success was not due to conservation of this trait but due to competitiveness for the added carbon. Adding 50KBq of 14 C sample -1 enabled detection of 14 C in the sorted population at ∼ 60-600 times background; a sensitivity which demonstrates potential extension to analysis of rarer/less active populations. Given its sensitivity and compatibility with obtaining a C mass balance, 14 C-FISH-FACS allows quantitative dissection of C flow within the microbial biomass that has hitherto not been achieved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Carbon 14 dating; La datation par le carbone 14

    Energy Technology Data Exchange (ETDEWEB)

    Laj, C.; Mazaud, A.; Duplessy, J.C. [CEA Saclay, Lab. des Sciences du Climat et de l' Environnement, 91 - Gif-sur-Yvette (France)

    2004-03-01

    In this article time dating based on carbon 14 method is reviewed, its limits are explained and recent improvements are presented. Carbon 14 is a by-product of the interactions of cosmic protons with air molecules. The fluctuations of the quantity of carbon 14 present in the atmosphere are responsible for the shift observed between the result given by the method and the real age. This shift appears for ages greater than 2000 years and is estimated to 1000 years for an age of 10.000 years. As a consequence carbon 14 dating method requires calibration by comparing with other methods like dendrochronology (till 11.000 years) and time dating of fossil corals (till 26.000 years and soon till 50.000 years). It is assumed that the fluctuations of carbon 14 in the atmosphere are due to: - the changes in the intensity and composition of cosmic radiations itself (due to the motion of the sun system through the galaxy or due to the explosion of a super-novae in the surroundings of the sun system); - the changes of the earth magnetic field that diverts cosmic rays; and - the changes in the interactions between the atmosphere and the oceans knowing that 40 tons of carbon 14 are dissolved in seas while only 1 ton belongs to the atmosphere. (A.C.)

  9. Carbon 14 dating method

    International Nuclear Information System (INIS)

    Fortin, Ph.

    2000-01-01

    This document gives a first introduction to 14 C dating as it is put into practice at the radiocarbon dating centre of Claude-Bernard university (Lyon-1 univ., Villeurbanne, France): general considerations and recalls of nuclear physics; the 14 C dating method; the initial standard activity; the isotopic fractioning; the measurement of samples activity; the liquid-scintillation counters; the calibration and correction of 14 C dates; the preparation of samples; the benzene synthesis; the current applications of the method. (J.S.)

  10. Carbon-14 in sludge

    International Nuclear Information System (INIS)

    Fowler, J.R.; Coleman, C.J.

    1983-01-01

    The level of C-14 in high-level waste is needed to establish the amount of C-14 that will be released to the environment either as off-gas from the Defense Waste Processing Facility (DWPF) or as a component of saltstone. Available experimental data confirmed a low level of C-14 in soluble waste, but no data was available for sludge. Based on the processes used in each area, Purex LAW sludge in F-area and HM HAW sludge in H-area will contain the bulk of any sludge produced by the cladding. Accordingly, samples from Tank 8F containing Purex LAW and Tank 15H containing HM HAW were obtained and analyzed for C-14. These two waste types constitute approximately 70% of the total sludge inventory now stored in the waste tanks. Results from analyses of these two sludge types show: the total C-14 inventory in sludge now stored in the waste tanks is 6.8 Ci; C-14 releases to the atmosphere from the DWPF will average approximately 0.6 Ci annually at the projected sludge processing rate in the DWPF. 4 references, 2 tables

  11. Carbon-14 in tree rings

    International Nuclear Information System (INIS)

    Cain, W.F.; Suess, H.E.

    1976-01-01

    In order to investigate how reliably the carbon 14 content of tree rings reflects that of atmospheric carbon dioxide, two types of determinations were carried out: (1) carbon 14 determinations in annual rings from the beginning of this century until 1974 and (2) carbon 14 determinations in synchronous wood from the North American bristlecone pine and from European oak trees, dendrochronologically dated to have grown in the third and fourth century B.C. The first series of measurements showed that bomb-produced radiocarbon was incorporated in wood at a time when it was converted from sapwood to heartwood, whenever radiocarbon from bomb testing was present in the atmosphere. The second series showed that wood more than 2000 years old and grown on two different continents at different altitudes had, within the limits of experimental error, the same radiocarbon content. This work and other experimental evidence, obtained in part by other laboratories, show that tree rings reflect the average radiocarbon content of global atmospheric carbon dioxide accurately within several parts per mil. In rare cases, deviations of up to 10 parts per thousand may be possible. This means that a typical single radiocarbon date for wood or charcoal possesses an intrinsic uncertainty (viz., an estimated ''one-sigma error'' in addition to all the other errors) of the order of +-50 years. This intrinsic uncertainty is independent of the absolute age of the sample. More accurate dates can, in principle, be obtained by the so-called method of ''wiggle matching.''

  12. Selection of a carbon-14 fixation form

    International Nuclear Information System (INIS)

    Scheele, R.D.; Burger, L.L.

    1982-09-01

    This report summarizes work on the selection of a disposal form for carbon-14 produced during the production of nuclear power. Carbon compounds were screened on the basis of solubility, thermal stability, resistance to oxidation, cost and availability, compatibility with the selected disposal matrix, leach resistance when incorporated in concrete, and compatibility with capture technologies. Carbonates are the products of the various technologies presently considered for carbon-14 capture. The alkaline earth carbonates exhibit the greatest thermal stabilities, lowest solubilities, lowest raw material cost, and greatest raw material availabilities. When reactions with cement and its impurities are considered, calcium and strontium carbonates are the only alkaline earth carbonates resistant to hydrolysis and reaction with sulfate. Leaching tests of barium, calcium, lead, potassium, and strontium carbonates in concrete showed calcium carbonate concrete to be slightly superior to the other alkaline earth carbonates, and greatly superior to a soluble carbonate, potassium carbonate, and lead carbonate. None of the additives to the concrete reduced the carbonate leaching. Acidic CO 2 -containing waters were found to greatly increase carbonate leaching from concrete. Sea water was found to leach less carbon from carbonate concretes than either distilled water or Columbia River water, which showed nearly equivalent leaching. Based on our work, calcium, barium, and strontium carbonates in concrete are the most suitable waste forms for carbon-14, with calcium carbonate concrete slightly superior to the others. If the waste form is to be exposed to natural waters, sea water will have the lowest leach rate. 6 figures, 7 tables

  13. Adsorption of carbon-14 on mortar

    International Nuclear Information System (INIS)

    Matsumoto, Junko; Banba, Tsunetaka; Muraoka, Susumu

    1995-01-01

    The sorption experiments of carbon-14 on the mortar grain (grain size: 0.50--1.0 mm) focused on the chemical form of the carbon-14 were carried out by the batch method. Three kinds of carbon-14 chemical form were used for the experiments: sodium carbonate (Na 2 14 CO 3 ) as the inorganic radiocarbon, and sodium acetate (CH 3 14 COONa) and acetaldehyde ( 14 CH 3 14 CHO) as the organic radiocarbons. 0.30 gram samples of mortar were soaked in the solution with carbon-14 at 15 C for periods of up to 160 days. At the end of each run, carbon-14 concentrations in the supernatants were determined before and after centrifugation (3,500 rpm., 1 hr). In the mortar-sodium carbonate system, the retention process of carbon-14 related to reaction on the surface of the mortar was speculated as follows. First, 3CaO-SiO 2 and 2CaO-SiO 2 of the mortar components contact with water and produce Ca(OH) 2 . Ca(OH) 2 produces Ca 2+ and OH - in the solution. Then, calcite forms from Ca 2+ and CO 3 2- in the solution. Thus, the sorption ratio of carbon-14 onto mortar will be high until mortar has been completely carbonated because Ca 2+ is rich in the mortar and the solubility of calcite is low. In the mortar-organic carbon system, the soluble organic carbon-14 is hardly sorbed on the surface of the mortar. Therefore, the cementitious materials may not inhibit the release of organic radiocarbons from the low-level radioactive wastes, contrary to the case of inorganic radiocarbon

  14. Carbon-14 as an hydrology tool

    International Nuclear Information System (INIS)

    Garcia y G, E.; Albarran B, R.

    1977-01-01

    Carbon-14 and tritium results from the action of cosmic radiation and of nuclear tests also. In general carbon-14 resulting from nuclear arms tests is of no interest from the hydrological point-of view, as tritium is a more efficient marker of juvenile waters through having a much shorter disintegration period. Radioactive carbon oxidizes and forms carbon dioxide which mixes with atmospheric carbon dioxide and enters the global carbon cycle. Use of carbon-14 in the dating of subterranean waters is based on the fact that the carbon dioxide found in the soil zone is of biologic origin arising from the respiration and decomposition of plant roots. Therefore it contains carbon-14 taken from the atmosphere by the plants. This carbon dioxide of biogenic origin is dissolved in infiltrating water and is borne along towards the water bearing strata. Its carbon-14 content decrease through radioactive loss and the fractional remainder of the original contents indicates the time which has passed since it left the supply zone in the soil, that is, the time passed since it filtrated the water. (author)

  15. Carbon-14 Bomb-Pulse Dating

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, B A

    2007-12-16

    Atmospheric testing of nuclear weapons during the 1950s and early 1960s doubled the concentration of carbon-14 atmosphere and created a pulse that labeled everything alive in the past 50 years as carbon moved up the food chain. The variation in carbon-14 concentration in time is well-documented and can be used to chronologically date all biological materials since the mid-1950s.

  16. The carbon 14 and environment; Le carbone 14 et l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This article resume the history and the properties of the carbon 14 ({sup 14}C). We also find the different origins and the produced quantities. The carbon transfers in environment are explained and so the {sup 14}C. The biological effects and the sanitary aspects are clarified. The measurements of carbon 14 are given as well its application through the dating. The waste management is tackled. (N.C.)

  17. Carbon and carbon-14 in lunar soil 14163

    International Nuclear Information System (INIS)

    Fireman, E.L.; Stoenner, R.W.

    1981-01-01

    Carbon is removed from the surface of lunar soil 14163 size fractions by combustions at 500 and 1000 0 C in an oxygen stream and the carbon contents and the carbon-14 activities are measured. The carbon contents are inversely correlated with grain size. A measured carbon content of 198 ppM for bulk 14163, obtained by combining the size fraction results, is modified to 109 +- 12 ppM by a carbon contamination correction. This value is in accord with a previous determination, 110 ppM, for bulk 14163. The small ( 53 μ) grains, 11.2 +- 2.0 dpm/kg. The combusted carbon and carbon-14 are attributed mainly to solar-wind implantation. Melt extractions of carbon-14 from the combusted soil samples gave essentially identical activities, 21.0 +- 1.5 and 19.2 +- 2.0 dpm/kg for the small and large grains, and are attributed to cosmic-ray spallation-produced carbon-14

  18. Carbon 14 and tritium radioactivity of alcohols

    International Nuclear Information System (INIS)

    Guerain, J.; Tourliere, S.

    1975-01-01

    The method of measuring carbon 14 radioactivity of alcohols has been perfected in order to establish the correct determination of synthetic alcohol added to fermentation alcohol. The specific carbon and tritium activity of alcohol of different origins have been determined for 1973 and 1974. The Suess effect and nuclear fall-out are observed [fr

  19. Carbon-14 measurements in aquifers with methane

    International Nuclear Information System (INIS)

    Barker, J.F.; Fritz, P.; Brown, R.M.

    1979-01-01

    A survey of various groundwater systems indicates that methane is a common trace constituent and occasionally a major carbon species in groundwaters. Thermocatalytic methane had delta 13 Csub(CH 4 )>-45 per mille and microbially produced or biogenic methane had delta 13 Csub(CH 4 ) 13 C values for the inorganic carbon. Thermocatalytic methane had no apparent effect on the inorganic carbon. Because methanogenesis seriously affects the carbon isotope geochemistry of groundwaters, the correction of raw 14 C ages of affected groundwaters must consider these effects. Conceptual models are developed which adjust the 14 C activity of the groundwater for the effects of methanogenesis and for the dilution of carbon present during infiltration by simple dissolution of rock carbonate. These preliminary models are applied to groundwaters from the Alliston sand aquifer where methanogenesis has affected most samples. In this system, methanogenic bacteria using organic matter present in the aquifer matrix as substrate have added inorganic carbon to the groundwater which has initiated further carbonate rock dissolution. These processes have diluted the inorganic carbon 14 C activity. The adjusted groundwater ages can be explained in terms of the complex hydrogeology of this aquifer, but also indicate that these conceptual models must be more rigorously tested to evaluate their appropriateness. (author)

  20. Production of carbon-14 and preparation of some key precursors for labeling organic molecules

    International Nuclear Information System (INIS)

    Moriya, T.; Motoishi, S.

    1992-01-01

    Production of carbon-14 on 50 GBq scale has been performed by neutron irradiation of aluminium nitride target in the JMTR. This nuclide is separated in carbon dioxide form by combustion of the irradiated target at 1100degC with oxygen. The [ 14 C] carbon dioxide liberated thus is trapped in caustic solution and finally recovered as [ 14 C] barium carbonate. Some precursors useful for incorporating carbon-14 into a given organic molecule have been prepared. Precursors such as [1- 14 C] sodium acetate, [ 14 C] methanol and [ 14 C] potassium cyanide are prepared by rather conventional methods involving carbonation of methyl magnesium iodine, reduction of carbon dioxide with lithium aluminium hydride and reduction of carbonate with metallic potassium in the presence of ammonium salt, respectively. A catalytic polymerization of acetylene is used to prepare benzene. (author)

  1. Synthesis of carbon-14 labeled vigabatrin. [Antieplileptic

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, A.J.; Wagner, E.R. (Marion Merrell Dow Inc, Indianapolis, IN (United States))

    1993-01-01

    Carbon-14 labeled vigabatrin was synthesized in 5 steps from 5-hydroxymethyl-2-pyrrolidone tosylate and NaCN-[[sup 14]C]. A key step involved reduction of the resulting nitrile in the presence of excess dimethylamine to give the dimethylamino-ethyl 2-pyrrolidone derivative in one step. This afforded an overall radiochemical yield of 22% and radiochemical purity greater than 98%. (Author).

  2. Synthesis of carbon-14 labelled ethyl chloride

    International Nuclear Information System (INIS)

    Kanski, R.

    1976-01-01

    A new efficient method of synthesis of ethyl chloride (1,2- 14 C), based on the Ba 14 CO 3 and dry hydrogen chloride as starting materials has been developed and described. Addition of the hydrogen chloride to ethylene (1,2- 14 C), obtained from Ba 14 CO 3 , has been carried out in the presence of the AlCl 3 as catalyst. The outlined method leads to ethyl chloride (1,2- 14 C) of high specific activity. The radiochemical yield of the reaction based on the activity of barium carbonate used was 72%. (author)

  3. Carbon-14 production in nuclear reactors

    International Nuclear Information System (INIS)

    Davis, W. Jr.

    1977-01-01

    The radioactive nuclide 14 C is formed in all nuclear reactors due to absorption of neutrons by carbon, nitrogen, or oxygen. These may be present as components of the fuel, moderator, or structural hardware, or they may be present as impurities. Most of the 14 C formed in the fuels or in the graphite of HTGRs will be converted to a gaseous form at the fuel reprocessing plant, primarily as carbon dioxide; this will be released to the environment unless special equipment is installed to collect it and convert it to a solid for essentially permanent storage. If the 14 C is released as carbon dioxide or in any other chemical form, it will enter the biosphere, be inhaled or ingested as food by nearly all living organisms including man, and will thus contribute to the radiation burden of these organisms. Detailed estimates are presented of the amounts of 14 C formed in LWRs, HTGR, and LMFBR with emphasis on those pathways that are likely to lead to the release of this nuclide, either at the reactor site or at the fuel reprocessing plant. 83 references

  4. Concentration of carbon-14 in plants

    International Nuclear Information System (INIS)

    1978-01-01

    The carbon-14 survey program initiated 1960 to gather data on current levels of carbon-14 in environments. Plants essential oil and fermented alcohol were selected as sample materials. The carbon contained in these materials is fixed from atmospheric carbon dioxide by anabolism, so they well reflect the variation of carbon-14 in biosphere. Thymol; Thymol was obtained from the essential oil of Orthodon Japonicium Benth which was cultivated and harvested every year in the experimental field of NIRS and Chiba University. The methylation was carried out to eliminate the strong quenching action of the phenolic group of thymol. Eighteen grams of thymol methyl ether was used as liquid scintillator by adding 0.4% PPO and 0.01% POPOP. Menthol; Menthol was obtained from Mentha arvensis L which was cultivated in the east part of Hokkaido and prepared by Kitami Factory of Federation of Agricultural Cooperative Society of Hokkaido. The chemical conversion of menthol to p-cymene was carried out and used as liquid scintillator as same as above sample. Lemongrass oil; Lemongrass oil was obtained from Cymbopogon citratus Stapf which was cultivated in Izu Experimental Station of Medicinal Plants, National Institute of Hygienic Science located Minami-Izu, Shizuoka Pref. The p-cymene derived from Lemongrass oil was used as liquid scintillator. Alcohol; All sample of fermented alcohol were obtained from the Alcohol Factories of Ministry of Trade and Industry. Raw materials of alcohol were sweet potatos cultivated in several prefectures in Japan ''high test'' molasses and blackstrap molasses imported from several countries of Asia, South America and South Africa, crude alcohol imported from U.S.A., Argentina and Brazil. Mixed solvent of 10 ml sample alcohol and 10 ml toluene or p-xylene containing 0.8% PPO and 0.1% dimethyl POPOP was used as liquid scintillator. (author)

  5. On the Chinese Carbon Reduction Target

    Directory of Open Access Journals (Sweden)

    Michinori Uwasu

    2010-06-01

    Full Text Available In November 2009, China pledged a 40–45% decrease in CO2 emissions per GDP by 2020, as compared with the 2005 level. Although carbon intensity (emission targets by nature are ambiguous, this study demonstrates that China’s pledge is consistent with the current Chinese domestic agenda that simultaneously pursues economic growth and energy security. The target numbers in the pledge seem reasonable, given the technological feasibility and measures, considered along with the assumption that moderate economic growth will occur. However, the study also argues that financial and institutional constraints exist as potential obstacles to achieving the target if the trend of the current economic tendencies continues.

  6. A gaseous measurement system for carbon-14 dioxide and carbon-14 methane: An analytical methodology to be applied in the evaluation of the carbon-14 dioxide and carbon-14 methane produced via microbial activity in volcanic tuff

    International Nuclear Information System (INIS)

    Dolan, M.M.

    1987-01-01

    The objectives of this study were to develop a gaseous measurement system for the carbon-14 dioxide and carbon-14 methane produced via microbial activity or geochemical action on leachate in tuff; to determine the trapping efficiency of the system for carbon-14 dioxide; to determine the trapping efficiency of the system for carbon-14 methane; to apply the experimentally determined factors regarding the system's trapping efficiency for carbon-14 dioxide and carbon-14 methane to a trapping algorithm to determine the activity of the carbon-14 dioxide and carbon-14 methane in a mixed sample; to determine the minimum detectable activity of the measurement process in picocuries per liter; and to determine the lower limit or detection of the measurement process in counts per minute

  7. LDEO Carbon 14 Data from Selected Sea floor Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Carbon-14 data in this file were compiled by W.F. Ruddiman and staff at the Lamont-Doherty Earth Observatory of Columbia University. Data include 974 carbon-14 dates...

  8. Global impact of carbon-14 from nuclear power reactors

    International Nuclear Information System (INIS)

    Moghissi, A.A.; Carter, M.W.

    1977-01-01

    Carbon-14 is produced by nuclear power reactors, predominently as a result of the interaction of a neutron and nitrogen-14 both in the fuel and in the coolant. Several other reactions also contribute to the production of carbon-14. Present operational procedures, in general, for reactors and fuel reprocessing plants result in the release of carbon-14 into the environment. Combustion of fossil fuels and certain industrial operations contribute to the supply of CO 2 in the atmosphere and this contribution is essentially free of carbon-14. Future carbon-14 burdens by assuming a thorough mixing of all CO 2 in the atmosphere is predicted. Available data on electric power generation, fossil fuel combustion and certain other information are used to calculate the projected specific activity of carbon-14 by the year 2000 and the twenty-first century. According to these calculations, the global population dose from carbon-14 can be substantial. Also, carbon-14 in the vicinity of nuclear power reactors is considered. Because of the chemistry of carbon-14, it is shown that local problems may be more significant around BWR's as compared to PWR's. Based on environmental considerations of carbon-14, its increasing production and discharge into the atmosphere, and available control technology, it is recommended that nitrogen use and its presence be minimized in pertinent reactor components and operations

  9. Carbon 14 in the aquatic food chain

    International Nuclear Information System (INIS)

    Mueller, H.; Fischer, E.

    1983-01-01

    In the links of the food chain consisting of water, water plants, and fish from 6 several aquatic ecosystems, the specific C-14 activity of the carbon was determined from 1979 to 1981 and compared with values of the terrestrial food chain. The mean values obtained from the specific acitivities of the links were between 203 and 321 mBq/g C (5.5 and 8.7 pCi/g C). Four of the six mean values differ from the values for the terrestrial food chain of 260 to 240 mBg/g C (7.0 to 6.5 pCi/g C) investigated for 1979 to 1980. The specific-acitivity model is valid for the aquatic food chain only if atmosphere and man are not included as chain links. (orig.) [de

  10. An improved synthesis of carbon-14 labelled carboxylic acids from carbon-14 labelled amino acids

    International Nuclear Information System (INIS)

    Ramamurthy, T.V.; Ravi, S.; Viswanathan, K.V.

    1988-01-01

    Various carbon-14 labelled amino acids including the aromatic ones viz., tyrosine, phenylalanine and tryptophan are converted to the corresponding carboxylic acids in high yield (70-90%) on a micromolar scale synthesis by reaction with hydroxyl-amine-O-sulphonic acid and in a short reaction time. The improvement in yield has been achieved by using aqeuous alcohol as solvent in lieu of water alone as the medium of reaction. (author)

  11. The lichens, tritium and carbon 14 integrators; Les lichens, integrateurs de tritium et de carbone 14

    Energy Technology Data Exchange (ETDEWEB)

    Daillant, O

    2007-07-01

    The present report concerns a research for the tritium and for the carbon 14 in lichens in a spirit of bio-indication: the first results appear in Daillant and al (2004 ) and additional results were presented to the congress B.I.O.M.A.P. in Slovenia, organized collectively by the institute Josef Stefan from Ljubljana and the international atomic energy agency from Vienna (Daillant and al 2003). (N.C.)

  12. Measurement of carbon-14 in hydrological samples

    International Nuclear Information System (INIS)

    Hussain, S.D.

    1991-11-01

    Thermal neutrons produced by cosmic rays or nuclear weapon tests interact with atmospheric nitrogen resulting in the formation of radiocarbon which, after oxidation into carbon dioxide, follows the natural carbon cycle. The partial pressure of carbon dioxide in the soil is several times that in the atmosphere due to plant root respiration and decay of organic matter. Water absorbs biogenic carbon dioxide while percolating through the unsaturated zone. The carbon content of groundwater is mainly in the form of bicarbonate ions. The extraction of carbon from water sample as barium carbonate is carried out in the field. Benzene is synthesised from the carbonate sample. The activity of radiocarbon in the synthesised benzene is determined by using a liquid scintillation analyzer. Details of sampling procedure, benzene synthesis, counter calibration and treatment of sample data have been given. 7 figs. (author)

  13. Dual labelling of Lobuprofen with tritium and carbon-14

    International Nuclear Information System (INIS)

    Santamaria, J.; Rivera, P.; Esteban, M.; Martin, J.L.; Carretero, J.M.

    1988-01-01

    Dual labelling of Lobuprofen with tritium and carbon-14 was performed. The synthesis between 2-(4-isobutylphenyl)propionic acid (Ibuprofen), randomly labelled with tritium, and 2-[4-(3-chlorophenyl)-1-piperazinyl]ethanol (Cl-Alkanol) labelled with carbon-14 in the piperazine ring was achieved. Prior to this synthesis, the [ 14 C]Cl-Alkanol was obtained using 2-amino-[2- 14 C]ethanol as a precursor. (author)

  14. Quality of Graphite Target for Biological/Biomedical/Environmental Applications of 14C-Accelerator Mass Spectrometry

    Science.gov (United States)

    2010-01-01

    Catalytic graphitization for 14C-accelerator mass spectrometry (14C-AMS) produced various forms of elemental carbon. Our high-throughput Zn reduction method (C/Fe = 1:5, 500 °C, 3 h) produced the AMS target of graphite-coated iron powder (GCIP), a mix of nongraphitic carbon and Fe3C. Crystallinity of the AMS targets of GCIP (nongraphitic carbon) was increased to turbostratic carbon by raising the C/Fe ratio from 1:5 to 1:1 and the graphitization temperature from 500 to 585 °C. The AMS target of GCIP containing turbostratic carbon had a large isotopic fractionation and a low AMS ion current. The AMS target of GCIP containing turbostratic carbon also yielded less accurate/precise 14C-AMS measurements because of the lower graphitization yield and lower thermal conductivity that were caused by the higher C/Fe ratio of 1:1. On the other hand, the AMS target of GCIP containing nongraphitic carbon had higher graphitization yield and better thermal conductivity over the AMS target of GCIP containing turbostratic carbon due to optimal surface area provided by the iron powder. Finally, graphitization yield and thermal conductivity were stronger determinants (over graphite crystallinity) for accurate/precise/high-throughput biological, biomedical, and environmental14C-AMS applications such as absorption, distribution, metabolism, elimination (ADME), and physiologically based pharmacokinetics (PBPK) of nutrients, drugs, phytochemicals, and environmental chemicals. PMID:20163100

  15. Cell Nucleus-Targeting Zwitterionic Carbon Dots.

    Science.gov (United States)

    Jung, Yun Kyung; Shin, Eeseul; Kim, Byeong-Su

    2015-12-22

    An innovative nucleus-targeting zwitterionic carbon dot (CD) vehicle has been developed for anticancer drug delivery and optical monitoring. The zwitterionic functional groups of the CDs introduced by a simple one-step synthesis using β-alanine as a passivating and zwitterionic ligand allow cytoplasmic uptake and subsequent nuclear translocation of the CDs. Moreover, multicolor fluorescence improves the accuracy of the CDs as an optical code. The CD-based drug delivery system constructed by non-covalent grafting of doxorubicin, exhibits superior antitumor efficacy owing to enhanced nuclear delivery in vitro and tumor accumulation in vivo, resulting in highly effective tumor growth inhibition. Since the zwitterionic CDs are highly biocompatible and effectively translocated into the nucleus, it provides a compelling solution to a multifunctional nanoparticle for substantially enhanced nuclear uptake of drugs and optical monitoring of translocation.

  16. Carbon-14 labelling of biomolecules induced by 14CO ionized gas

    International Nuclear Information System (INIS)

    Lier, J.E. van; Sanche, L.

    1979-01-01

    Ionized 14 CO gas provides a rapid method for producing 14 C-labelled biomolecules. The apparatus consists of a high vacuum system in which a small amount of 14 CO is ionized by electron impact. The resulting species drift towards a target where they interact with the molecule of interest to produce 14 C-labelled compounds. Since the reaction time is only 2 minutes, the method is particularly promising for producing tracer biomolecules with short-lived 11 C at high specific activities. The applicability of the method to various classes of compounds of biological importance, including steroids, alkaloids, prostaglandins, nucleosides, amino acids and proteins has been studied. All compounds treated gave rise to 14 C addition and degradation products. Furthermore, for some compounds, chromatographic analysis in multiple systems followed by derivatization and crystallization to constant specific activity, indicated that carbon exchange may occur to produce the labelled, but otherwise unaltered substrate in yields of the order of 10-100 mCi/mol. More conclusive proof of radiochemical identity must await production of larger quantities of material and rigorous purification including at least two different chromatographic techniques. (author)

  17. The EC CAST project (carbon-14 source term)

    International Nuclear Information System (INIS)

    Williams, S. J.

    2015-01-01

    Carbon-14 is a key radionuclide in the assessment of the safety of underground geological disposal facilities for radioactive wastes. It is possible for carbon-14 to be released from waste packages in a variety of chemical forms, both organic and inorganic, and as dissolved or gaseous species The EC CAST (CArbon-14 Source Term) project aims to develop understanding of the generation and release of carbon-14 from radioactive waste materials under conditions relevant to packaging and disposal. It focuses on the release of carbon-14 from irradiated metals (steels and zirconium alloys), from irradiated graphite and from spent ion-exchange resins. The CAST consortium brings together 33 partners. CAST commenced in October 2013 and this paper describes progress to March 2015. The main activities during this period were reviews of the current status of knowledge, the identification and acquisition of suitable samples and the design of experiments and analytical procedures. (authors)

  18. The synthesis of carbon-14 labeled pravastatin

    International Nuclear Information System (INIS)

    Wallace, M.A.; Dean, D.C.; Ellsworth, R.L.; Melillo, D.G.; Marks, T.; White, R.F.

    1993-01-01

    An asymmetric route to [ 14 C]β-hydroxycompactin 1 bearing the (S)-2-methyl-[1- 14 C]butanoate side chain has been developed. Methylation of [N-[1- 14 C]butyryl]-4-(S)-phenylmethyl-2-oxazolidinone 4 afforded a 95:5 mixture of diastereomeric [N-(S,R)-2-methyl-[1- 14 C]butyryl]-4-(S)-phenylmethyl-2-oxazolidi nones 5,6 which were separated by preparative HPLC. Oxidative cleavage of 5 afforded optically pure (S)-2-methyl-[1- 14 C]butanoic acid. Acylation of alcohol 9 with optically pure (S)-2-methyl-[1- 14 C] butyryl chloride afforded ester 10. Removal of the silyl ether produced diastereomerically pure compactin 11. Hydroxylation was carried out by biotransformation with Mucor hiemelus to afford diastereomerically pure [[1- 14 C]butanoate]β-hydroxycompactin, [ 14 C]Pravastatin 1. (Author)

  19. Preparation of carbon-14-labelled gallic acid

    International Nuclear Information System (INIS)

    Kozak, I.; Prochazka, M.

    1977-01-01

    Gallic acid labelled with 14 C was prepared for the needs of biological studies. A lithium derivative of trimethoxybenzene was treated with 14 CO 2 and then demethylated to yeld [carboxyl- 14 C]gallic acid. The preparation scheme and the individual steps of the synthesis are described in detail

  20. Distribution of carbon-14 assimilated by wheat awns

    International Nuclear Information System (INIS)

    Olugbemi, L.B.

    1978-01-01

    The pattern of distribution of carbon assimilated by awns was investigated in two lines of Triticum aestivum. Single awns on basal florets of spikelets in the central part of the ear were dosed with 14 C0 2 . Five days after dosing, 99% of the carbon-14 recovered was in the spikelet bearing the awn. Of the carbon-14 exported from the treated awn 57% went to the grain of the first floret, 1% to the second, 28% to the third and 7% to the fourth. (author)

  1. Gases and carbon in metals. Pt. 14

    International Nuclear Information System (INIS)

    Jehn, H.; Speck, H.; Hehn, W.; Fromm, E.; Hoerz, G.

    1981-01-01

    This issue is part of a series of data on 'Gases and Carbon in Metals' which supplements the data compilation in the book 'Gase und Kohlenstoff in Metallen' (Gases and Carbon in Metals), edited by E. Fromm and E. Gebhardt, Springer-Verlag, Berlin 1976. The present survey includes results from papers published after the copy deadline and recommends critically selected data. Furthermore, it comprises a bibliography of relevant literature. For each element, firstly data on binary systems are presented, starting with hydrogen and followed by carbon, nitrogen, oxygen, and rare gases. Within one metal-metalloid system the data are listed under topics such as solubility, solubility limit, dissociation pressure of compounds, vapour pressure of volatile oxides, thermodynamic data, diffusion, transport parameters (effective valence, heat of transport), permeation of gases through metals, gas absorption and gas desorption kinetics, compound formation kinetics, precipitation kinetics, and property changes. Following the data on binary systems, the data of ternary systems are presented, beginning with systems which contain one metal and two gases or one gas and carbon and continuing with systems with two metals and one gas or carbon. (orig./GE)

  2. Quantifying Carbon-14 for Biology Using Cavity Ring-Down Spectroscopy

    OpenAIRE

    McCartt, A. Daniel; Ognibene, Ted J.; Bench, Graham; Turteltaub, Kenneth W.

    2016-01-01

    A cavity ring-down spectroscopy (CRDS) instrument was developed using mature, robust hardware for the measurement of carbon-14 in biological studies. The system was characterized using carbon-14 elevated glucose samples and returned a linear response up to 387 times contemporary carbon-14 concentrations. Carbon-14 free and contemporary carbon-14 samples with varying carbon-13 concentrations were used to assess the method detection limit of approximately one-third contemporary carbon-14 levels...

  3. Isotopic labelling with carbon-14 and tritium

    International Nuclear Information System (INIS)

    Evans, E.A.

    1980-01-01

    In this paper general methods of isotopic labelling with 14 C and with 3 H are briefly reviewed with special attention to examples of compounds likely to be of wide interest in biological research. (author)

  4. Chemoenzymatic synthesis of carbon-14 labelled antioxidants

    International Nuclear Information System (INIS)

    Deigner, H.P.; Freyberg, C.; Heck, R.

    1993-01-01

    The syntheses of [ 14 C] labelled antioxidants are described. We developed an efficient synthetic methodology to prepare a series of labelled amides with antioxidant activity, starting from [ 14 C] KCN and alkyl or aryl halides. By a combination of nucleophilic displacement of halides by [ 14 C] cyanide, mediated by ultrasound and subsequent mild and selective enzymatic hydrolysis of the resulting nitriles, labelled carboxylic acids were obtained. Labelled amines were prepared by reduction of the respective nitriles. Availability of [ 14 C] KCN, efficient introduction of the label by ultrasound mediated reaction and selective and mild hydrolysis by commercially available nitrilase (Rhodococcus sp.), makes possible a wide range of applications of this methodology in the synthesis of functionalized labelled compounds. (Author)

  5. The preparation of glucose uniformly labelled with carbon-14

    International Nuclear Information System (INIS)

    Garcia Pineda, M.D.; Suarez Contreras, C.; Rodrigo Gonzalez, M.E.

    1978-01-01

    The plant, (Zea mais, L) and culture conditions for an optimum production of glucose has been chosen. To achieve the labelling of glucose, photosynthesis and carboxylation are carried on, under an artificial atmosphere of 14CO 2 produced from 14 C -barium carbonate. Following photosynthesis the sugars are extracted, and then the extract purified by several methods. The purified glucose is finally, degraded and the specific radioactivity is determined in each of its carbon atoms. (Author) 37 refs

  6. Carbon-14 in reactor plant water

    International Nuclear Information System (INIS)

    Knowles, G.K.

    1979-01-01

    The method for the analysis of 14 C in reactor plant water and various waste streams previously used at the Idaho National Engineering Laboratory has been shown to be ineffective for samples which contain organic compounds. The previous method consisted of acidification and refluxing of the sample, precipitation of the liberated CO 2 , and subsequent analysis by the liquid scintillation method. The method was simple but it did not convert all compounds containing 14 C in the sample to CO 2 . The new method, while it is based on the previous method, has been improved by employing a strong oxidant, potassium persulfate and silver nitrate, for more complete oxidation of the organics to CO 2 . The new method yields 14 C values that have typically been one to two orders of magnitude higher than the values obtained using the former method. This indicates that most of the 14 C present in the current reactor water samples being analyzed is associated with trace amounts of organics

  7. Dynamics of carbon 14 in soils: a review

    International Nuclear Information System (INIS)

    Tamponnet, C.

    2004-01-01

    In terrestrial ecosystems, soil is the main interface between atmosphere, hydrosphere, lithosphere and biosphere. Its interactions with carbon cycle are primordial. Information about carbon 14 dynamics in soils is quite dispersed and an up-to-date status is therefore presented in this paper. Carbon 14 dynamics in soils are governed by physical processes (soil structure, soil aggregation, soil erosion) chemical processes (sequestration by soil components either mineral or organic), and soil biological processes (soil microbes, soil fauna, soil biochemistry). The relative importance of such processes varied remarkably among the various biomes (tropical forest, temperate forest, boreal forest, tropical savannah, temperate pastures, deserts, tundra, marshlands, agro ecosystems) encountered in the terrestrial eco-sphere. Moreover, application for a simplified modelling of carbon 14 dynamics in soils is proposed. (author)

  8. Carbon-14 labeling of phytoplankton carbon and chlorophyll a carbon: determination of specific growth rates

    International Nuclear Information System (INIS)

    Welschmeyer, N.A.; Lorenzen, C.J.

    1984-01-01

    The pattern of photosynthetic 14 C labeling over time is described for phytoplankton. The carbon-specific growth rate (d -1 ) is defined explicitly by changes in the specific activity (dpm μg -1 C) of the algae. For Skeletonema costatum, growing in axenic batch culture, the specific activities of both total cellular carbon and chlorophyll carbon increase at equal rates and the change in specific activity with time follows the predicted pattern. The specific activity of 14 C-labeled chlorophyll a was used to estimate phytoplankton growth rates and C:Chl ratios of field samples in Dabob Bay (Puget Sound), Washington. Growth rates decreased with depth and C:Chl ratios were higher for samples incubated under high light intensity. In several instances the C:Chl ratio increased from the beginning to the end of the incubation; this trend was most conspicuous near surface light intensities and for days of high total incident radiation. On these occasions, Chl a was actively 14 C labeled, yet little (or even negative) change was noted in the concentration of Chl a. These results suggest that some process (or processes) of chlorophyll degradation must be active at the same time that chlorophyll is being synthesized

  9. Determination of carbon-14 environmental samples by mixing 14CO2 with a liquid scintillator

    International Nuclear Information System (INIS)

    Garcia Sanz, M.R.; Gomez, V.; Heras, M.C.; Beltran, M.A.

    1990-01-01

    A method for the determination of Carbon-14 ( 14 CO 2 ) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO 2 ) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discused and compared. The method of collection of atmospheric samples is also described. (Author)

  10. Determination of Carbon-14 in environmental samples by mixing 14CO2 with a liquid scintillator

    International Nuclear Information System (INIS)

    Garcia, M. R.; Gomez, V.; Heras, M. C.; Beltran, M. A.

    1990-01-01

    A method for the determination of Carbon-14 (14CO2) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO2) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discussed and compared. The method of collection of atmospheric samples is also described. (Author) 10 refs

  11. Syntheses of carbon-14 and sulfur-35 labeled 2-(Morpholinothio)-benzothiazoles and carbon-14 labeled 2-(Cyclohexylaminothio)-benzothiazoles

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, A.; Fukuoka, M.; Adachi, T.; Yamaha, T.

    1986-04-01

    Some vulcanizing accelerators, mercaptobenzothiazole derivatives labeled with carbon-14 or sulfur-35 were prepared. 2-(Morpholinothio)benzothiazole labeled with carbon-14 or sulfur-35 of the sulfhydryl group at position 2 was synthesized by oxidative condensation with sodium hypochlorite from a mixture of morpholine and 2-mercaptobenzothiazole-2-/sup 14/C or 2-mercaptobenzothiazole-2-/sup 35/S. The same method was applicable to the synthesis of 2-(morpholino-U-/sup 14/C-thio) -benzothiazole using morpholine-U-/sup 14/C as starting material. 2-(Cyclohexylaminothio)benzothiazole-2-/sup 14/C was prepared, by oxidation with a mixture of iodine and potassium iodide, from cyclohexylamine and 2-mercapto-benzothiazole-2-/sup 14/C, which was synthesized from carbon-/sup 14/C disulfide and 2-mercaptoaniline in the presence of trace sodium sulfide in dimethylformamide. 2-(Cyclohexyl-U-/sup 14/C-aminothio)benzothiazole was also obtained from cylcohexyl-amine-U-/sup 14/C and 2-mercaptobenzothiazole.

  12. Synthesis of carbon-13 and carbon-14 labeled paldimycin tri-sodium salt

    International Nuclear Information System (INIS)

    Hsi, R.S.P.; Witz, D.F.; Visser, J.; Stolle, W.T.; Ditto, C.L.

    1989-01-01

    Carbon-14 labeled paldimycin trisodium salt was prepared by addition of N-acetyl-L-cysteine to [ 14 C]paulomycin, the radioactive antibiotic produced by fermentation of Streptomyces paulus in the presence of L-methionine labeled with carbon-14 in the S-methyl group. Carbon-13 nuclear magnetic resonance (NMR) spectra of paulomycin produced when the fermentation was carried out in the presence of L-[S-methyl- 13 C]methionine showed that the isotope incorporation had occurred specifically at the methoxy group of ring C, i.e., the 2-deoxy sugar portion of paulomycin. With sustained slow feed of labeled precursors during the optimum antibiotic production period, carbon-14 isotope yields of up to 17.5% with specific activity of up to 11.4 μCi per milligram of paulomycin, and carbon-13 isotope yields of up to 24% with 17-fold isotope enrichment over natural abundance, were achieved. (author)

  13. Fine-Grained Targets for Laser Synthesis of Carbon Nanotubes

    Science.gov (United States)

    Smith, Michael W. (Inventor); Park, Cheol (Inventor)

    2017-01-01

    A mechanically robust, binder-free, inexpensive target for laser synthesis of carbon nanotubes and a method for making same, comprising the steps of mixing prismatic edge natural flake graphite with a metal powder catalyst and pressing the graphite and metal powder mixture into a mold having a desired target shape.

  14. Evaluation of carbon-14 life cycle in reactors VVER-1000

    International Nuclear Information System (INIS)

    Lysakova, Katerina; Neumann, Jan; Vonkova, Katerina

    2012-09-01

    This work is aimed at the evaluation of carbon-14 life cycle in light water reactors VVER-1000. Carbon-14 is generated as a side product in different systems of nuclear reactors and has been an issue not only in radioactive waste management but mainly in release into the environment in the form of gaseous effluents. The principal sources of this radionuclide are in primary cooling water and fuel. Considerable amount of C-14 is generated by neutron reactions with oxygen 17 O and nitrogen 14 N present in water coolant and fuel. The reaction likelihood and consequently volume of generated radioisotope depends on several factors, especially on the effective cross-section, concentrations of parent elements and conditions of power plant operating strategies. Due to its long half-life and high capability of integration into the environment and thus into the living species, it is very important to monitor the movement of carbon-14 in all systems of nuclear power plant and to manage its release out of NPP. The dominant forms of radioactive carbon-14 are the hydrocarbons owing to the combinations with hydrogen used for absorption of radiolytic oxygen. These organic compounds, such as formaldehyde, methyl alcohol, ethyl alcohol and formic acid can be mostly retained on ion exchange resins used in the system for purifying primary cooling water. The gaseous carbon compounds (CH 4 and CO 2 ) are released into the atmosphere via the ventilation systems of NPP. Based on the information and data obtained from different sources, it has been designed a balance model of possible carbon-14 pathways throughout the whole NPP. This model includes also mass balance model equations for each important node in system and available sampling points which will be the background for further calculations. This document is specifically not to intended to describe the best monitoring program attributes or technologies but rather to provide evaluation of obtained data and find the optimal way to

  15. Carbon-14 measurements and characterization of dissolved organic carbon in ground water

    International Nuclear Information System (INIS)

    Murphy, E.M.

    1987-01-01

    Carbon-14 was measured in the dissolved organic carbon (DOC) in ground water and compared with 14 C analyses of dissolved inorganic carbon (DIC). Two field sites were used for this study; the Stripa mine in central Sweden, and the Milk River Aquifer in southern Alberta, Canada. The Stripa mine consists of a Precambrian granite dominated by fracture flow, while the Milk River Aquifer is a Cretaceous sandstone aquifer characterized by porous flow. At both field sites, 14 C analyses of the DOC provide additional information on the ground-water age. Carbon-14 was measured on both the hydrophobic and hydrophilic organic fractions of the DOC. The organic compounds in the hydrophobic and hydrophilic fractions were also characterized. The DOC may originate from kerogen in the aquifer matrix, from soil organic matter in the recharge zone, of from a combination of these two sources. Carbon-14 analyses, along with characterization of the organics, were used to determine this origin. Carbon-14 analyses of the hydrophobic fraction in the Milk River Aquifer suggest a soil origin, while 14 C analyses of the hydrophilic fraction suggest an origin within the Cretaceous sediments (kerogen) or from the shale in contact with the aquifer

  16. The 14 mu m band of carbon stars

    NARCIS (Netherlands)

    Yamamura, [No Value; de Jong, T; Waters, LBFM; Cami, J; Justtanont, K; LeBertre, T; Lebre, A; Waelkens, C

    1999-01-01

    We have studied the absorption bands around 14 mum in the spectra of 11 carbon stars with mass-loss rates ranging from 10(-8) to 10(-4) M-circle dot yr(-1), based on data obtained with the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory (ISO). All stars clearly show a

  17. The metabolism and dosimetry of carbon-14 labelled compounds

    International Nuclear Information System (INIS)

    Crawley, F.E.H.

    1977-01-01

    The number of compounds labelled at high specific activity with carbon-14 has greatly increased over the last few years. There are limited biological data available to enable an assessment of the internal radiation dose and to identify the critical tissues after an intake of such compounds. The ICRP consider two Model Systems for deriving dose. Both Models assume a total elimination of the carbon-14 in the breath and only bone or whole body as critical tissues and are not representative of the majority of the compounds now available. A research programme has been established to study the rate of excretion and tissue distribution of selected carbon-14 labelled compounds in the rat after intravenous injection, pulmonary and gastric intubation and skin absorption. These metabolic data have been used to calculate the committed dose equivalent and maximum permissible annual intake (MPAI) for various tissues in man on the assumption that the experimental data obtained in the rat are true for man. To date potassium 14 C-cyanide and 14 C-methanol have been studied. The values for the MPAI's derived from the doses to individual tissues are more restrictive than values calculated from the whole body doses. The MPAI calculated from excretion data in terms of whole body dose is 31 mCi for 14 C-cyanide and 25 mCi for 14 C-methanol. However, the critical tissue for 14 C-cyanide is the stomach with an MPAI of 1.5 mCi based on a dose of 10.7 rem mCi -1 . This was an order of magnitude greater than the dose to any other region of the GI tract and 5 times that to the testis. The critical organs for 14 C-methanol are the testis (MPAI 2.5 mCi) for males and the ovaries (MPAI 6.2 mCi) for females

  18. Terrestrial carbon storage dynamics: Chasing a moving target

    Science.gov (United States)

    Luo, Y.; Shi, Z.; Jiang, L.; Xia, J.; Wang, Y.; Kc, M.; Liang, J.; Lu, X.; Niu, S.; Ahlström, A.; Hararuk, O.; Hastings, A.; Hoffman, F. M.; Medlyn, B. E.; Rasmussen, M.; Smith, M. J.; Todd-Brown, K. E.; Wang, Y.

    2015-12-01

    Terrestrial ecosystems have been estimated to absorb roughly 30% of anthropogenic CO2 emissions. Past studies have identified myriad drivers of terrestrial carbon storage changes, such as fire, climate change, and land use changes. Those drivers influence the carbon storage change via diverse mechanisms, which have not been unified into a general theory so as to identify what control the direction and rate of terrestrial carbon storage dynamics. Here we propose a theoretical framework to quantitatively determine the response of terrestrial carbon storage to different exogenous drivers. With a combination of conceptual reasoning, mathematical analysis, and numeric experiments, we demonstrated that the maximal capacity of an ecosystem to store carbon is time-dependent and equals carbon input (i.e., net primary production, NPP) multiplying by residence time. The capacity is a moving target toward which carbon storage approaches (i.e., the direction of carbon storage change) but usually does not attain. The difference between the capacity and the carbon storage at a given time t is the unrealized carbon storage potential. The rate of the storage change is proportional to the magnitude of the unrealized potential. We also demonstrated that a parameter space of NPP, residence time, and carbon storage potential can well characterize carbon storage dynamics quantified at six sites ranging from tropical forests to tundra and simulated by two versions (carbon-only and coupled carbon-nitrogen) of the Australian Community Atmosphere-Biosphere Land Ecosystem (CABLE) Model under three climate change scenarios (CO2 rising only, climate warming only, and RCP8.5). Overall this study reveals the unified mechanism unerlying terrestrial carbon storage dynamics to guide transient traceability analysis of global land models and synthesis of empirical studies.

  19. Chinas carbon-intensity target: climate actors and policy developments

    Energy Technology Data Exchange (ETDEWEB)

    Stensdal, Iselin

    2012-11-01

    China has become the largest GHG emitting country, and announced in 2009 its first policy objective measured in carbon emissions. The carbon-intensity target is to reduce the carbon intensity by 40-45 % by 2020 compared to 200 levels. Since then there has been further policy developments in order to attain the reduction carbon intensity and steer China towards a low-carbon development. The 12th 5-year plan (2011-2015) is strong on incentives for reducing China's carbon intensity such as energy conservation measures and the establishment of new market-based mechanisms. While the central government forms the policies, the implementation is dependent on a range of actors. In addition to the climate change bureaucracy, the positive forces and actors on GHG mitigation is presented. All in all, there are promising developments in China for the years to come.(auth)

  20. Carbon-14 dating of groundwater under Christchurch, 1976 samples

    International Nuclear Information System (INIS)

    Stewart, M.K.; Brenninkmeijer, C.A.M.; Brown, L.J.

    1986-06-01

    Four samples of groundwater from deep aquifers under Christchurch have been analysed for carbon-14, tritium, oxygen-18 and chemical contents. Interpretation of the carbon-14 results requires two steps, (1) correction of the measured 14 C values for input of dead ( 14 C-free) carbon underground (indicating that the measured values of 80 PMC* should be increased to about 120 PMC), and (2) determination of water residence times for given flow models of the groundwater system. Interpretation of tritium results involves step 2 only. Three models are considered, of which the third is considered most appropriate to Christchurch. In this model, the 14 C and T results indicate that a small proportion of young water (post-1954) mixes with a larger proportion of older water (probably at least several hundred years). The oxygen-18 content indicates that recharge is mainly from the Waimakariri River and possibly from rainfall and streams near the foothills of the Canterbury Plains. Other aspect of the groundwater flow under Christchurch are discussed

  1. Preparation of pyridostigmine bromide labeled with carbon-14 and tritium

    Energy Technology Data Exchange (ETDEWEB)

    Kepler, J.A.; Twine, C.E.; Austin, R.D. (Research Triangle Inst., Research Triangle Park, NC (United States))

    1992-08-01

    [2-[sup 14]C]Pyridostigmine bromide was prepared in 17.6% radiochemical yield with specific activity of 18 mCi/mmol. The reaction sequence involved preparation of 2-furan[[sup 14]C]carboxylic acid by carbonation of 2-lithiofuran, followed by conversion to 2-amino[[sup 14]C]methylfuran by lithium aluminium hydride reduction of its carboxamide. Oxidative rearrangement of 2-amino[[sup 14]C]methylfuran gave 3-hydroxy[2-[sup 14]C]pyridine which was converted to [2-[sup 14]C]pyridostigmine bromide by reaction with dimethylcarbamyl chloride and quarternization with bromomethane. Pyridostigmine bromide labeled in the methyl group of the carbamate function was prepared in 73% yield with specific activity of 37.6 mCi/mmol by reaction of bis-3-pyridyl carbonate with [[sup 14]C]dimethylamine followed by quarternization with bromomethane. [6-[sup 3]H]-Pyridostigmine bromide with specific activity of 22.5 mCi/mmol was prepared by catalytic halogen-tritium replacement of 2,6-dibromo-3-dimethylcarbamyloxypyridine followed by quarternization with bromomethane and back-exchanging the labile 2-tritium. (author).

  2. Preparation of pyridostigmine bromide labeled with carbon-14 and tritium

    International Nuclear Information System (INIS)

    Kepler, J.A.; Twine, C.E.; Austin, R.D.

    1992-01-01

    [2- 14 C]Pyridostigmine bromide was prepared in 17.6% radiochemical yield with specific activity of 18 mCi/mmol. The reaction sequence involved preparation of 2-furan[ 14 C]carboxylic acid by carbonation of 2-lithiofuran, followed by conversion to 2-amino[ 14 C]methylfuran by lithium aluminium hydride reduction of its carboxamide. Oxidative rearrangement of 2-amino[ 14 C]methylfuran gave 3-hydroxy[2- 14 C]pyridine which was converted to [2- 14 C]pyridostigmine bromide by reaction with dimethylcarbamyl chloride and quarternization with bromomethane. Pyridostigmine bromide labeled in the methyl group of the carbamate function was prepared in 73% yield with specific activity of 37.6 mCi/mmol by reaction of bis-3-pyridyl carbonate with [ 14 C]dimethylamine followed by quarternization with bromomethane. [6- 3 H]-Pyridostigmine bromide with specific activity of 22.5 mCi/mmol was prepared by catalytic halogen-tritium replacement of 2,6-dibromo-3-dimethylcarbamyloxypyridine followed by quarternization with bromomethane and back-exchanging the labile 2-tritium. (author)

  3. Carbon-14 geochemistry at the Savannah River Site

    International Nuclear Information System (INIS)

    Roberts, Kimberly A.; Kaplan, Daniel I.

    2013-01-01

    Carbon-14 is among the key radionuclides driving risk at the E-Area Low-Level Waste Disposal Facility on the Savannah River Site (SRS). Much of this calculated risk is believed to be the result of having to make conservative assumptions in risk calculations because of the lack of site-specific data. The original geochemical data package (Kaplan 2006) recommended that performance assessments and composite analyses for the SRS assume that 14 C did not sorbed to sediments or cementitious materials, i.e., that C-14 K d value (solid:liquid concentration ratio) be set to 0 mL/g (Kaplan 2006). This recommendation was based primarily on the fact that no site-specific experimental work was available and the assumption that the interaction of anionic 14 C as CO 2 2- ) with similarly charged sediments or cementitious materials would be minimal. When used in reactive transport equations, the 0 mL/g Kd value results in 14 C not interacting with the solid phase and moving quickly through the porous media at the same rate as water. The objective of this study was to quantify and understand how aqueous 14 C, as dissolved carbonate, sorbs to and desorbs from SRS sediments and cementitious materials. Laboratory studies measuring the sorption of 14 C, added as a carbonate, showed unequivocally that 14 C-carbonate K d values were not equal to 0 mL/g for any of the solid phases tested, but they required several months to come to steady state. After six months of contact, the apparent K d values for a clayey sediment was 3,000 mL/g, for a sandy sediment was 10 mL/g, for a 36-year-old concrete was 30,000 mL/g, and for a reducing grout was 40 mL/g. Furthermore, it was demonstrated that (ad)sorption rates were appreciably faster than desorption rates, indicating that a kinetic sorption model, as opposed to the steady-state K d model, may be a more accurate description of the 14 C-carbonate sorption process. A second study demonstrated that the 14 C-carbonate sorbed very strongly onto the

  4. Carbon 14 dating method; Methode de datation par le carbone 14

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, Ph

    2000-07-01

    This document gives a first introduction to {sup 14}C dating as it is put into practice at the radiocarbon dating centre of Claude-Bernard university (Lyon-1 univ., Villeurbanne, France): general considerations and recalls of nuclear physics; the {sup 14}C dating method; the initial standard activity; the isotopic fractioning; the measurement of samples activity; the liquid-scintillation counters; the calibration and correction of {sup 14}C dates; the preparation of samples; the benzene synthesis; the current applications of the method. (J.S.)

  5. Carbon budget of a marine phytoplankton-herbivore system with carbon-14 as a tracer

    International Nuclear Information System (INIS)

    Copping, A.E.; Lorenzen, C.J.

    1980-01-01

    Adult female and stage V Calanus pacificus were fed 14 C-labeled phytoplankton in the laboratory in the form of monospecific cultures and natural populations. A carbon budget was constructed by following the 14 C activity and the specific activity, over 48 h, in the phytoplankton, copepod, dissolved organic, dissolved inorganic, and fecal carbon compartments. The average incorporation of carbon into the copepod's body was 45% of the phytoplankton carbon available. Of the phytoplankton carbon, 27% appeared as dissolved organic carbon, 24% as dissolved inorganic carbon, and 3 to 4% in the form of fecal pellets. All of the tracer was recovered at the end of the experiments. The specific activity of the phytoplankton compartment was constant throughout each experiment. The other compartments had initial specific activities of zero, or close to zero, and increased throughout the experiment. In most experiments, the copepod specific activity equalled that of the phytoplankton at the end of 48 h, while the dissolved organic carbon, dissolved inorganic carbon, and fecal specific activities remained well below that of the phytoplankton

  6. Accelerator mass analyses of meteorites - carbon-14 terrestrial ages

    International Nuclear Information System (INIS)

    Miura, Y.; Rucklidge, J.; Beukens, R.; Fireman, E.

    1988-01-01

    Carbon-14 terrestrial ages of ten Antarctic meteorites have been measured by the IsoTrace accelerator mass spectrometry (AMS). The 14 C terrestrial age of 1 gram sample was determined from 14 C concentrations collected at melt and re-melt temperatures, compared with the 14 C concentration of the known Bruderheim chondrite. Yamato-790448 (LL3) chondrite was found to be the oldest terrestrial age of 3x10 4 years in the nine Yamato chondrites, whereas Yamato-791630 (L4) chondrite is considered to be the youngest chondrites less than thousand years. Allan Hills chondrite of ALH-77231 (L6) shows older terrestrial age than the nine Yamato chondrites. New accelerator data of the terrestrial age show higher accuracy with smaller sample than the previous counting method. (author)

  7. Synthesis of carbon-14 analogue of 1,5 diaryl-5-[14C]-1,2,3-triazoles

    International Nuclear Information System (INIS)

    Matloubi, Hojatollah; Shafiee, Abbas; Saemian, Nader; Shirvani, Gholamhossein; Daha, Fariba Johari

    2004-01-01

    Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-methyl-phenyl)-1,2,3-triazole and 1-(4-methylsulfone-phenyl)-5-phenyl-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-tolunitrile-[cyano- 14 C] and benzonitrile-[cyano- 14 C], respectively

  8. The management of carbon-14 in Canadian nuclear facilities

    International Nuclear Information System (INIS)

    1995-07-01

    In Canada, Derived Emission Limits (DELs) for the release of radionuclides from nuclear facilities are set to ensure that the dose to a member of a critical group from one year's release does not exceed the limit on annual dose to a member of the public set by the Atomic Energy Control Regulations. The Advisory Committee on Radiological Protection (ACRP) has expressed concerns as to whether this procedure provides adequate protection to members of the public, including future generations, for certain radionuclides such as a carbon-14 ( 14 C), which can accumulate in the environment and which can be dispersed, through environmental processes, beyond the local region where the critical group is assumed to live. The ACRP subsequently established a Working Group to review the production, release, environmental levels, and waste management of 14 C arising in CANDU power reactors. The ACRP recommendations resulting from this review can be summarized as · Given the current levels of emissions from CANDU nuclear power stations resulting from the use of a carbon dioxide annulus gas and the limitations in the calculation and use of collective dose, the ACRP sees no need for and additional collective dose limit to be applied to these sources. · The AECB should require licensees of power reactors and waste management sites to provide an annual inventory of 14 C held within reactor buildings and waste management sites; to provide information on the stability of the ion exchange resins and their continuing ability to retain the 14 C; to demonstrate on an ongoing basis that releases of 14 C are maintained at a small fraction of the emission limits; and to report annually the critical group and local collective doses arising from releases of 14 C. 61 refs., 25 tabs., 4 figs

  9. Carbon-14 dating of tree rings for tritium measurement

    International Nuclear Information System (INIS)

    Yamada, Y.; Yasuike, K.; Kiriyama, N.; Komura, K.; Ueno, K.

    1998-01-01

    The carbon-14 concentration in tree-ring cellulose of an 80-year-old pine tree which has been used for tritium measurement was measured during the 1941-1987 period. This was done to determine the formation year of each tree ring in order to study the pathway of tritium uptake into the tree rings. In the 1941 to 1953 period, the δ 14 C value remained slightly lower than 0 per mille. It began to increase from 1954 to a small broad peak of 250 per mille between 1959 and 1961, followed by rapid increase to the highest value of approximately 800 per mille in 1964. Since 1964, it had been diminishing year by year to reach a level of 190 per mille in 1987. The two peak years coincided with those in the known carbon-14 patterns in tree rings. However, there existed a difference in the amplitude of the δ 14 C values during the period of 1963-1967. (author)

  10. Monitoring and removal of gaseous carbon-14 species

    International Nuclear Information System (INIS)

    Kabat, M.J.

    1979-01-01

    A simple and efficient method was developed for the monitoring of low level carbon-14 in nuclear power station areas and gaseous effluent. Gaseous carbon compounds (hydrocarbons and CO) are catalytically oxidized to CO 2 , which is then absorbed on solid Ca(OH) 2 at elevated temperatures. The 14 C collected is quantitatively liberated by thermal decomposition of CaCO 3 as CO 2 , which is either measured directly by flow-through detectors or absorbed in alkali hydroxide followed by liquid scintillation counting. The method can also be used for the removal of gaseous 14 C. The Ca 14 CO 3 can be immobilized in concrete for long term disposal. Ca(OH) 2 is an inexpensive absorber. It is selective for CO 2 and has high capacity and efficiency for its absorption and retention. A theoretical evaluation of thee optium conditions for CO 2 absorption and liberation is discussed and experimental investigations are described. There is good agreement between theoretical predictions and experimental findings

  11. Carbon-14 discharges from the nuclear fuel cycle: Pt. 1

    International Nuclear Information System (INIS)

    McCartney, M.; Baxter, M.S.; Scott, E.M.

    1988-01-01

    The radiological impact of 14 C produced by the nuclear fuel cycle is assessed using an advanced 25-box model of the carbon cycle coupled with a range of feasible energy-use scenarios. In particular, this study estimates both the short- and long-term dose implications to the global population. In the former context, it is predicted that the atmospheric 14 C specific activity in the year 2050 will be 234 Bq kg -1 (carbon), corresponding to delivery of an individual effective dose equivalent rate of 15 μSv year -1 . The contribution of reactor-derived 14 C to the individual dose rate increases steadily throughout this period, reaching 1.8 μSv year -1 in 2050, well within ICRP limits. In the longer term, however, the collective effective dose equivalent commitment is conservatively estimated at 141 man Sv TBq -1 , corresponding to 480 man Sv (GW(e) year) -1 . These figures indicate that 14 C could generate one of the largest contributions to the total dose to man from nuclear power production. (author)

  12. A detective from the past called carbon 14; Un detective del pasado llamado carbono 14

    Energy Technology Data Exchange (ETDEWEB)

    Trintan, R. M.

    2015-07-01

    The analysis is carried out using Radiometry or Accelerator mass spectrometry. After the system allowing to date the age of any organic rest - whether a fossil, a wood fragment, a parchment or a seed - is an isotope called carbon-14. An atom that comes from reactions nuclear produced in the atmosphere and cosmic-ray-induced they interact with oxygen to form carbon dioxide. This element they absorb it plants in photosynthesis and then passes to the animals remained almost unchanged during the life of the organism. to the meet the initial ratio of c-14 that had been in the atmosphere before his death, the remains that are left in it determine the elapsed time. (Author)

  13. Investigations on the biokinetics of carbon 14 in algae cultures

    International Nuclear Information System (INIS)

    Leister, W.

    1981-01-01

    The uptake of 14 C by Scenedesmus quadricauda is quantitatively investigated by simulation models of radio ecological relevance. Due to the complexing of the procedures in the natural ecosystem, it was only possible to consider idealized conditions. The batch culture ressembles the conditons of still waters or relatively still waters without notable water exchange. The effect of the 14 C enrichment, as well as the drastic carbon reduction in the substrate as a result of algae growth, was avoided in the modified batch culture under conditions of simultaneous substrate diffusion by means of a permeation system. The 14 C and 12 C uptake of the cells thus took place solely under the conditions of constant concentration in the culture medium. The consequences for flowing water resulting from a nuclear power plant accident are to be simulated for the extent of the 14 C uptake by green algae using the continuous culture model with dynamic 14 C exposure. The continuous infusion of 14 C in the continuous culture corresponds to the possible cases where 14 C escapes into a flowing water at a constant rate over a long period of time, whether this may be via chronical release from a nuclear power plant or by 'fallout' resulting from nuclear arms testing. The results shown lead to the conclusion that the emission of 14 C to the environment, which according to prognoses will be considerably higher after the year 2000, presents a serious radioactivity potential which man and environment will have to live with should these developments continue and the prognoses come true. (orig./MG) [de

  14. Carbon 14 distribution in irradiated BWR fuel cladding and released carbon 14 after aqueous immersion of 6.5 years

    Energy Technology Data Exchange (ETDEWEB)

    Sakuragi, T. [Radioactive Waste Management Funding and Research Center, Tsukishima 1-15-7, Chuo City, Tokyo, 104-0052 (Japan); Yamashita, Y.; Akagi, M.; Takahashi, R. [TOSHIBA Corporation, Ukishima Cho 4-1, Kawasaki Ward, Kawasaki, 210-0862 (Japan)

    2016-07-01

    Spent fuel cladding which is highly activated and strongly contaminated is expected to be disposed of in an underground repository. A typical activation product in the activated metal waste is carbon 14 ({sup 14}C), which is mainly generated by the {sup 14}N(n,p){sup 14}C reaction and produces a significant exposure dose due to the large inventory, long half-life (5730 years), rapid release rate, and the speciation and consequent migration parameters. In the preliminary Japanese safety case, the release of radionuclides from the metal matrix is regarded as the corrosion-related congruent release, and the cladding oxide layer is regarded as a source of instant release fraction (IRF). In the present work, specific activity of {sup 14}C was measured using an irradiated BWR fuel cladding (Zircaloy-2, average rod burnup of 41.6 GWd/tU) which has an external oxide film having a thickness of 25.3 μm. The {sup 14}C specific activity of the base metal was 1.49*10{sup 4} Bq/g, which in the corresponding burnup is comparable to values in the existing literature, which were obtained from various irradiated claddings. Although the specific activity in oxide was 2.8 times the base metal activity due to the additive generation by the {sup 17}O(n,α){sup 14}C reaction, the {sup 14}C abundance in oxide was less than 10% of total inventory. A static leaching test using the cladding tube was carried out in an air-tight vessel filled with a deoxygenated dilute NaOH solution (pH of 12.5) at room temperature. After 6.5 years, {sup 14}C was found in each leachate fraction of gas phase and dissolved organics and inorganics, the total of which was less than 0.01% of the {sup 14}C inventory of the immersed cladding tube. A simple calculation based on the congruent release with Zircaloy corrosion has suggested that the 96.7% of released {sup 14}C was from the external oxide layer and 3.3% was from the base Zircaloy metal. However, both the {sup 14}C abundance and the low leaching rate

  15. S14 as a Therapeutic Target in Breast Cancer

    National Research Council Canada - National Science Library

    Kinlaw, William

    2004-01-01

    .... Our aims are first to develop a model of anti-S14 breast cancer therapy in mice. Intratumoral adenoviral delivery of an S14-antisense gene into human breast cancer cell xenografts caused a significant inhibition of tumor growth...

  16. S14 as a Therapeutic Target in Breast Cancer

    Science.gov (United States)

    2006-08-01

    recombinant adenoviruses. The blot (25 Ag protein/lane) was probed with an antibody specific for rat S14. Lane 1— Hyperthyroid , carbohydrate-fed rat liver...to that observed in liver from a hyperthyroid rat fed a fat-free, high carbohydrate diet (lane 1). Infection with Ad-rS14 accelerated the accumulation...1]). Insight into the metabolic function of S14 came from studies of rat he- patocytes, where inhibition of its expression prevented activation of

  17. Synthesis of carbon-14 analogue of 1,5 diaryl-5-[{sup 14}C]-1,2,3-triazoles

    Energy Technology Data Exchange (ETDEWEB)

    Matloubi, Hojatollah E-mail: hmatloubi@aeoi.org.ir; Shafiee, Abbas; Saemian, Nader; Shirvani, Gholamhossein; Daha, Fariba Johari

    2004-05-01

    Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-methyl-phenyl)-1,2,3-triazole and 1-(4-methylsulfone-phenyl)-5-phenyl-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-tolunitrile-[cyano-{sup 14}C] and benzonitrile-[cyano-{sup 14}C], respectively.

  18. Tests of intestinal absorption using carbon-14-labeled isotopes

    International Nuclear Information System (INIS)

    Fromm, H.; Sarva, R.P.

    1983-01-01

    Beta radiation-emitting isotopes are being used increasingly in diagnostic gastroenterology for the study of absorption. The major reason for the popularity of radioisotopes is that their use is convenient for patient and physician alike. They often obviate naso- or orointestinal intubation and the collection, storage, and analysis of stool. The radioactivity used for the studies of digestive and absorptive processes is small and is not hazardous. In spite of the safety of the radiolabeled compounds, their use is restricted in children and pregnant women. Therefore, for most tests, promising alternative methods that make use of the stable isotope of carbon, /sup 13/C, instead of the radioactive /sup 14/C have been developed. The analysis of stable isotopes requires more sophisticated technology than that of radioactive compounds, however. Only a few centers presently are equipped and staffed to analyze stable isotopes on a routine basis. In contrast, the analysis of radioactive isotopes has become a routine procedure in almost ever major laboratory. The last decade has brought the development of several radioactive absorption tests. The clinically most useful tests relate to the study of bile acid, fat, lactose, and xylose absorption. All of these tests utilize the excretion rate of /sup 14/CO/sub 2/ in breath after ingestion of a /sup 14/C-labeled compound as a measure of the rate of its absorption or malabsorption

  19. Dating of archaeological objects using Carbon-14 facilities

    International Nuclear Information System (INIS)

    Kamisah Hj Alias; Noraishah Othman; Nasasni Nasrol

    2004-01-01

    Dating is the key to organising all archaeological evidence. Furthermore, the development of dating methods, whether traditional or scientific, illustrates the ingenuity and lateral thinking that make archaeological problem-solving such a fascinating exercise. The development of MINT radiocarbon dating procedures is reviewed. Basic principles and counting techniques are discussed. A sample is converted by chemical methods into a suitable form, such as carbon dioxide followed by the acetylene gas, and the benzene end-product is placed inside a proportional counter to measure the radioactivity of 14 C. Not until some years ago did absolute dates by radiocarbon dating become a reality for prehistoric archaeology in Malaysia where thermoluminescence and fission-track dating had begun to provide a locally applicable dating method some decades earlier. Applications of radiocarbon dating procedures in the fields of archaeology are also discussed. (Author)

  20. Carbon Nanotubes: An Emerging Drug Carrier for Targeting Cancer Cells

    Science.gov (United States)

    Bhattacharya, Shiv Sankar; Mishra, Arun Kumar; Verma, Navneet; Verma, Anurag; Pandit, Jayanta Kumar

    2014-01-01

    During recent years carbon nanotubes (CNTs) have been attracted by many researchers as a drug delivery carrier. CNTs are the third allotropic form of carbon-fullerenes which were rolled into cylindrical tubes. To be integrated into the biological systems, CNTs can be chemically modified or functionalised with therapeutically active molecules by forming stable covalent bonds or supramolecular assemblies based on noncovalent interactions. Owing to their high carrying capacity, biocompatibility, and specificity to cells, various cancer cells have been explored with CNTs for evaluation of pharmacokinetic parameters, cell viability, cytotoxicty, and drug delivery in tumor cells. This review attempts to highlight all aspects of CNTs which render them as an effective anticancer drug carrier and imaging agent. Also the potential application of CNT in targeting metastatic cancer cells by entrapping biomolecules and anticancer drugs has been covered in this review. PMID:24872894

  1. Improved quality control of carbon-14 labelled compounds

    International Nuclear Information System (INIS)

    Leonhardt, J.W.; Fuchs, P.; Standtke, K.

    1997-01-01

    IUT Ltd is a producer of carbon-14 labelled organic compounds like benzene, methanol, phenol, formaldehyde, Na-acetates and also special ordered compounds. The quality control of these compounds is carried out by means of HPLC and GC-MS due to chemical purity. Molar activity was determined by Liquid Scintillation Counting and HPLC being equipped by a radioactivity detector. Unfortunately the accuracy of the activity determination was arrived only ±4% relatively. This error is too high because of the large dilution factors. In respect of the IUT accreditation as an analytical laboratory in Germany the accuracy had to be improved remarkably. Therefore the GC-MS-determination of molar activities of labelled compounds is used as the 14 C-labelled compound. A special evaluation code is used to determine the enrichment values relative to the unlabelled molecules. Taking into account the results of GC-MS the accuracy of molar activity determination is improved to ±2%. The spectra evaluation is demonstrated and some examples are discussed

  2. The preparation of glucose uniformly labelled with carbon-14; Preparacion de glucosa uniformemente marcada con carbono-14

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M D; Suarez, C; Rodrigo, M E

    1978-07-01

    The plant, (Zea mais, L) and culture conditions for an optimum production of glucose has been chosen. To achieve the labelling of glucose, photosynthesis and carboxylation are carried on, under an artificial atmosphere of 14CO{sub 2} produced from 14{sup C}-barium carbonate. Following photosynthesis the sugars are extracted, and then the extract purified by several methods. The purified glucose is finally, degraded and the specific radioactivity is determined in each of its carbon atoms. (Author) 37 refs.

  3. Study of the biogenesis of flavones and cinnamic acids by using molecules labelled with carbon 14

    International Nuclear Information System (INIS)

    Chabannes, Bernard

    1970-01-01

    This research thesis reports the study of flavones, flavonoid compounds and cinnamic acids which are very common as natural pigments in plant species. The author first reports the study of the synthesis of shikimic acid labelled with carbon 14 (biological methods of preparation, synthesis), and then the synthesis of prunin labelled with carbon 14. The next part reports the study of the transformation of prunin labelled with carbon 14 into cosmosiine in flowers with white cosmos. The author finally compares the introduction of cinnamic acid and of shikimic acid (both labelled with carbon 14) into the sinapic acid of red cabbage leaves

  4. The synthesis of SL-75.212 (Betaxolol) labelled with carbon 14: 1-[4-(2-cyclopropyl methoxyethyl-[1-14C]) phenoxy]-3-isopropyl amino-2-propanol

    International Nuclear Information System (INIS)

    Aubert, F.; Beaucourt, J.P.; Pichat, L.

    1982-01-01

    Carbonation with 14 CO 2 of the Grigard reagent 1 gave 4-benzyloxy [carboxyl- 14 C] benzoic acid: 2 (87 % yield). 2 was successively treated in diethyl ether solution with diazomethane and lithium aluminium hydride giving rise to [7- 14 C] 4 benzyloxybenzyl alcohol 4 (82 % yield). Alcohol 4 was transformed into the corresponding chloride 5 when exposed to thionylchloride in ether. 5 was condensed with NaCN in DMF to give the nitrile 6 which was hydrolysed into the acid 7 isolated in a 75 % overall yield from Ba 14 CO 3 . 7 gave the alcohol 9 by successive treatments with diazomethane and LiAlH 4 in ether. 9 with NaH gave the corresponding alkoxide which when condensed with bromomethylcyclopropane gave the ether 10 purified by silicagel column chromatography and isolated with an overall yield of 71 % from Ba 14 CO 3 . Hydrogenolysis of 10 gave the phenol 11. The epoxide 12 was secured by condensation with epichlorhydrin in presence of NaOH. After purification by silicagel column chromatography 10 was opened with isopropylamine leading to the target compound BETAXOLOL 13 isolated as the hydrochloride. After extensive purification by Sephadex G-10 column chromatography, SL 75.212 [ethyl-1- 14 C] was obtained in an overall yield of 26 % from barium [ 14 C] carbonate and a radiochemical purity better than 99 % (specific activity 57 mCi/mole). (author)

  5. Use of carbon-14 in soil organic matter studies

    International Nuclear Information System (INIS)

    Vimal, O.P.; Kamath, M.B.

    1974-01-01

    Despite a great deal of research work on various aspects of soil organic matter, there are many gaps in the knowledge of the process of humus formation. These limitations arise mainly from the complex and heterogenous nature of soil humus substances, analytical problems in separating the fresh and decomposable materials from the old stabilized true humus substances and the lack of a clear understanding of the chemical structure of the humic acid molecule. During recent years, the use of carbon-14 has helped to trace within soil, transformation of a number of metabolites upto the point where they turn into humus. These studies have changed the concepts of the formation and stability of soil humus substances, their colloidal chemical properties and the uptake of organomolecules by plant roots. The present paper presents a synoptic view of the use of radiocarbon in studying the kinetics of humification, nature of precursors in humic acid formation, turnover of soil organic matter and the direct effects of humus substances on plant growth. (author)

  6. Legionella pneumophila Carbonic Anhydrases: Underexplored Antibacterial Drug Targets

    Directory of Open Access Journals (Sweden)

    Claudiu T. Supuran

    2016-06-01

    Full Text Available Carbonic anhydrases (CAs, EC 4.2.1.1 are metalloenzymes which catalyze the hydration of carbon dioxide to bicarbonate and protons. Many pathogenic bacteria encode such enzymes belonging to the α-, β-, and/or γ-CA families. In the last decade, enzymes from some of these pathogens, including Legionella pneumophila, have been cloned and characterized in detail. These enzymes were shown to be efficient catalysts for CO2 hydration, with kcat values in the range of (3.4–8.3 × 105 s−1 and kcat/KM values of (4.7–8.5 × 107 M−1·s−1. In vitro inhibition studies with various classes of inhibitors, such as anions, sulfonamides and sulfamates, were also reported for the two β-CAs from this pathogen, LpCA1 and LpCA2. Inorganic anions were millimolar inhibitors, whereas diethyldithiocarbamate, sulfamate, sulfamide, phenylboronic acid, and phenylarsonic acid were micromolar ones. The best LpCA1 inhibitors were aminobenzolamide and structurally similar sulfonylated aromatic sulfonamides, as well as acetazolamide and ethoxzolamide (KIs in the range of 40.3–90.5 nM. The best LpCA2 inhibitors belonged to the same class of sulfonylated sulfonamides, together with acetazolamide, methazolamide, and dichlorophenamide (KIs in the range of 25.2–88.5 nM. Considering such preliminary results, the two bacterial CAs from this pathogen represent promising yet underexplored targets for obtaining antibacterials devoid of the resistance problems common to most of the clinically used antibiotics, but further studies are needed to validate them in vivo as drug targets.

  7. Preparation of 14C-labelled poly(l-menthyl isopropenyl carbonates)

    International Nuclear Information System (INIS)

    Comes, R.A.; Grubbs, H.J.

    1981-01-01

    The synthesis of 14 C-labelled poly(l-menthyl isopropenyl carbonate) is described. Experimental conditions are included for incorporation of 14 C into each of the carbon atoms in the molecule. High pressure liquid chromatography conditions are given for separation and purification of the labelled intermediates. (author)

  8. Hydrogen Transfer from Hantzsch 1,4-Dihydropyridines to Carbon-Carbon Double Bonds under Microwave Irradiation

    OpenAIRE

    Jean Jacques Vanden Eynde; Didier Barbry; Guy Cordonnier; Séverine Torchy

    2002-01-01

    1,4-Dihydropyridines (DHPs) have been used in the reduction of carbon-carbon double bonds under microwave irradiation without solvent. The efficiency of the reactions is dramatically dependent on the steric effects in the DHPs and on the electronic effects in the olefins.

  9. Environmental release of carbon-14 gas from a hypothetical nuclear waste repository

    International Nuclear Information System (INIS)

    Lehto, M.A.; Merrell, G.B.

    1994-01-01

    Radioisotopes may form gases in a spent nuclear fuel waste package due to elevated temperatures or degradation of the fuel rods. Radioactive carbon-14, as gaseous carbon dioxide, is one of the gaseous radioisotopes of concern at an underground disposal facility for spent nuclear fuel and high-level radioactive waste. Carbon-14 dioxide may accumulate inside an intact waste container. Upon breach of the container, a potentially large pulse of carbon-14 dioxide gas may be released to the surrounding environment, followed by a lower, long-term continuous release. If the waste were disposed of in an unsaturated geologic environment, the carbon-14 gas would begin to move through the unsaturated zone to the accessible environment. This study investigates the transport of radioactive carbon-14 gas in geologic porous media using a one-dimensional analytical solution. Spent nuclear fuel emplaced in a deep geologic repository located at a generic unsaturated tuff site is analyzed. The source term for the carbon-14 gas and geologic parameters was obtained from previously published materials. The one-dimensional analytical solution includes diffusion, advection, radionuclide retardation, and radioactive decay terms. Two hypothetical sites are analyzed. One is dominated by advective transport, and the other is dominated by diffusive transport. The dominant transport mechanism at an actual site depends on the site characteristics. Results from the simulations include carbon-14 dioxide travel times to the accessible environment and the total release to the environment over a 10,000-year period. The results are compared to regulatory criteria

  10. An efficient synthesis of carbon-14 labelled vigabatrin

    International Nuclear Information System (INIS)

    Gill, H.S.

    1995-01-01

    Vigabatrin-[6- 14 C] ((R,S)-4-amino-5-hexenoic-[6- 14 C] acid) was synthesized by employing Wittig condensation of 1-(1-butenyl) -2-oxo-5-pyrrolidinecarboxaldehyde with methyl-[ 14 C]-triphenyl-phosphonium iodide as the key step. The synthetic sequence involved 3 steps and produced the title compound in 70% overall yield with a radiochemical purity of 100%. (author)

  11. Laboratory Experiments to Evaluate Matrix Diffusion of Dissolved Organic Carbon Carbon-14 in Southern Nevada Fractured-rock Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Hershey, Ronald L. [Nevada University, Reno, NV (United States). Desert Research Institute; Fereday, Wyatt [Nevada University, Reno, NV (United States). Desert Research Institute

    2016-05-01

    Dissolved inorganic carbon (DIC) carbon-14 (14C) is used to estimate groundwater ages by comparing the DIC 14C content in groundwater in the recharge area to the DIC 14C content in the downgradient sampling point. However, because of chemical reactions and physical processes between groundwater and aquifer rocks, the amount of DIC 14C in groundwater can change and result in 14C loss that is not because of radioactive decay. This loss of DIC 14C results in groundwater ages that are older than the actual groundwater ages. Alternatively, dissolved organic carbon (DOC) 14C in groundwater does not react chemically with aquifer rocks, so DOC 14C ages are generally younger than DIC 14C ages. In addition to chemical reactions, 14C ages may also be altered by the physical process of matrix diffusion. The net effect of a continuous loss of 14C to the aquifer matrix by matrix diffusion and then radioactive decay is that groundwater appears to be older than it actually is. Laboratory experiments were conducted to measure matrix diffusion coefficients for DOC 14C in volcanic and carbonate aquifer rocks from southern Nevada. Experiments were conducted using bromide (Br-) as a conservative tracer and 14C-labeled trimesic acid (TMA) as a surrogate for groundwater DOC. Outcrop samples from six volcanic aquifers and five carbonate aquifers in southern Nevada were used. The average DOC 14C matrix diffusion coefficient for volcanic rocks was 2.9 x 10-7 cm2/s, whereas the average for carbonate rocks was approximately the same at 1.7 x 10-7 cm2/s. The average Br- matrix diffusion coefficient for volcanic rocks was 10.4 x 10-7 cm2/s, whereas the average for carbonate rocks was less at 6.5 x 10-7 cm2/s. Carbonate rocks exhibited greater variability in

  12. Modelling accidental releases of carbon 14 in the environment: application as an excel spreadsheet

    International Nuclear Information System (INIS)

    Le Dizes, S.; Tamponnet, C.

    2004-01-01

    An application as an Excel spreadsheet of the simplified modelling approach of carbon 14 transfer in the environment developed by Tamponnet (2002) is presented. Based on the use of growth models of biological systems (plants, animals, etc.), the one-pool model (organic carbon) that was developed estimates the concentration of carbon 14 within the different compartments of the food chain and in fine the dose to man by ingestion in the case of a chronic or accidental release of carbon 14 in a river or the atmosphere. Data and knowledge have been implemented on Excel using the object-oriented programming language VisualBasic (Microsoft Visual Basic 6.0). The structure of the conceptual model and the Excel sheet are first briefly exposed. A numerical application of the model under a scenario of an accidental release of carbon 14 in the atmosphere is then presented. Simulation results and perspectives are discussed. (author)

  13. The metabolism and dosimetry of carbon-14 labelled diethylenetriaminepentaacetic acid (DTPA)

    International Nuclear Information System (INIS)

    Crawley, F.E.H.; Haines, J.W.

    1978-01-01

    Male rats were given carbon-14 labelled Ca-DTPA either by intravenous injection or by pulmonary intubation. The elimination of the carbon-14 by excretion in urine, faeces and breath was followed, Chromatographic examination of the urine showed that no metabolic degradation of the 14 C-DTPA had occurred. The distribution of activity between lung, kidneys, bone, muscle and GI tract was also followed. The data obtained have been used to assess the radiation dose to man from an intake of 14 C-DTPA on the assumption that the behaviour of 14 C-DTPA in man is the same as in the rat. The results are discussed. (U K.)

  14. The preparation of glucosa uniformly labelled with carbon-14

    International Nuclear Information System (INIS)

    Garcia Pineda, D.; Suarez, C.; Rodrigo Gonzalez, E.

    1978-01-01

    The plant, (Zea mais, L) and culture conditions for an optimun production of glucose has been chosen. To achieve the labelling of glucose, photosynthesis and carboxilation are carried on under an artificial atmosphere of 1 4CO 2 produced from 1 4C-barium carbonate. Following photosynthesis, the sugars are extracted and then the extract purified by several methods. The purified glucose is, finally, degraded and the specific radiactivity is determined in each of its carbon atoms. (author)

  15. Metabolism and risks from tritium and carbon-14 in the developing organism

    International Nuclear Information System (INIS)

    Gerber, G.B.; Kirchmann, R.; Hoek, J. van den

    1987-01-01

    In this review the risks are considered from tritium and carbon-14 to the developing organs of mammals. It mainly deals with H-3 but the conclusions are largely valid also for C-14. The metabolism and average tissue of THO as well as of organically bound tritium are discussed. Dosimetry of radiosensitive structures is also considered. 14 refs.; 2 figs.; 1 table

  16. Uranium targets sandwiched between carbon layers for use on target wheels and on a Wobbler in heavy-ion bombardments

    International Nuclear Information System (INIS)

    Folger, H.; Hartmann, W.; Klemm, J.; Thalheimer, W.

    1989-01-01

    Uranium layers of ≅ 0.4 mg/cm 2 are evaporated by means of a 6 kW electron-beam gun onto 0.04 mg/cm 2 thick carbon films in a high-vacuum process; a protecting layer of ≅ 0.01 mg/cm 2 of carbon is added in the same vacuum cycle. The evaporation- and deposition yields are discussed and measurements of target characteristics are described. C/U/C sandwich targets in the shape of a sector of an annulus are prepared for use on rotating target wheels of 155 mm radius to be bombarded with a pulsed beam of heavy ions. One type of circular targets of 20 mm in diameter is mounted to a target wobbler. Both, wheel and wobbler, distribute the intensity of the heavy-ion beam to a larger area to reduce radiation damages. Examples of target applications will be mentioned. (orig.)

  17. Restoring degraded land: contributing to Aichi Targets 14, 15, and beyond

    DEFF Research Database (Denmark)

    Navarro, Laetitia M.; Marques, Alexandra; Ceausu, Silvia

    2018-01-01

    Restoration ecology is gaining momentum on the international conservation scene. In particular, restoring degraded ecosystems is central to Aichi Biodiversity Targets 14 and 15 set by the Convention on Biological Diversity. Depending on the definition of degradation, from 2 to 47% of the global...... for restoration. Finally, we assess national conservation targets to examine the potential multifaceted impacts of achieving Aichi Targets 14 and 15 on biodiversity and society....... land surface could require restoration. Here, we review the range of goals and approaches to restoration, from active interventions to more passive approaches such as rewilding. We identify biodiversity offsets, payments for ecosystem services and agri-enviromental schemes as enabling policy mechanisms...

  18. An efficient synthesis of carbon-14 labelled vigabatrin

    Energy Technology Data Exchange (ETDEWEB)

    Gill, H.S. [Marion Merrell Dow Research Inst., Cincinnati, OH (United States)

    1995-12-31

    Vigabatrin-[6-{sup 14}C] ((R,S)-4-amino-5-hexenoic-[6-{sup 14}C] acid) was synthesized by employing Wittig condensation of 1-(1-butenyl) -2-oxo-5-pyrrolidinecarboxaldehyde with methyl-[{sup 14}C]-triphenyl-phosphonium iodide as the key step. The synthetic sequence involved 3 steps and produced the title compound in 70% overall yield with a radiochemical purity of 100%. (author).

  19. Measurement of pion double charge exchange on carbon-13, carbon-14, magnesium-26, and iron-56

    International Nuclear Information System (INIS)

    Seidl, P.A.

    1985-02-01

    Cross sections for the /sup 13,14/C, 26 Mg, 56 Fe(π + ,π - )/sup 13,14/O, 26 Si, 56 Ni reactions were measured with the Energetic Pion Channel and Spectrometer at the Clinton P. Anderson Meson Physics Facility for 120 less than or equal to T/sub π/ less than or equal to 292 MeV and 0 less than or equal to theta less than or equal to 50. The double isobaric analog states (DIAS) are of primary interest. In addition, cross sections for transitions to 14 O(0 + , 5.92 MeV), 14 O(2 + , 7.77 MeV), 56 Ni(gs), 13 O(gs), and 13 O(4.21 MeV) are presented. The 13 O(4.21 MeV) state is postulated to have J/sup π/ = 1/2 - . The data are compared to previously measured double-charge-exchange cross sections on other nuclei, and the systematics of double charge exchange on T greater than or equal to 1 target nuclei leading to the DIAS are studied. Near the Δ 33 resonance, cross sections for the DIAS transitions are in disagreement with calculations in which the reaction is treated as sequential charge exchange through the free pion-nucleon amplitude, while for T/sub π/ > 200 MeV the anomalous features of the 164 MeV data are not apparent. This is evidence for significant higher order contributions to the double-charge-exchange amplitude near the reasonable energy. Two theoretical approaches that include two nucleon processes are applied to the DIAS data. 64 references

  20. Radiocarbon 14C differentiation of sparkling and carbonated wines

    International Nuclear Information System (INIS)

    Martin, G.E.; Krueger, H.W.; Burggraff, J.M.

    1985-01-01

    Specific 14 C-activities, percent of modern 14 C-activity, and calculated percent of fermentation CO 2 are presented for CO 2 contained in commercial sparkling wines, labeled as champagne or produced by the bulk (charmat) process. These data are given for the production years 1976-1982. The survey encompassed effervescent wines produced in Spain, Italy, West Germany, California, and New York. Addition of synthetic CO 2 to approximately 40 samples represented as sparkling wines was indicated by low 14 C-activities of CO 2 in these wines. Data for 14 C-activity were also presented for the ethanol distilled from sparkling wines for the years 1977-1980. In all cases, the 14 C-activity of ethanol was appropriate to the year of vintage

  1. Synthesis of bisaramil labelled with carbon-14 and deuterium

    International Nuclear Information System (INIS)

    Szammer, J.; Simon-Trompler, E.; Mlinko, S.

    1994-01-01

    [6,8- 14 C 2 ]-Bisaramil: 3-methyl-7-ethyl-9α-(4-chlorobenzoyloxy)-3,7-diazabicyclo/3. 3.1./nonane-[6,8- 14 C 2 ] monohydrochloride and [7-N-D 5 -ethyl]-Bisaramil: 3-methyl-7-[D 5 -ethyl]-9α-(4-chlorobenzoyloxy)-3,7-diazabicy clo/3.3.1./nonane monohydrochloride were synthesized in four steps from 14 CO 2 (6% overall yield) and in six steps from [D 6 ]-ethanol (4% overall yield), respectively. (Author)

  2. Synthesis of pyrimidinic nucleotides and nucleosides labelled with carbon 14, through tri-methylsilylated and lithiated derivatives

    International Nuclear Information System (INIS)

    Godbillon, Jacques

    1972-01-01

    After a presentation of the trimethysilylation, lithiation, and methylation processes, this research thesis reports the synthesis of methyl carbon 14 - 5 - uridine, of ethyl carbon 14 - 5 - desoxy - 2' - uridine, and of thymidine monophosphate - 5' (methyl carbon 14) by using silylated and lithiated derivatives. The author also reports preliminary studies of biological studies of the trimethylsilyl-5-uridine and of the iodine-6-thymine

  3. Model study of atmospheric transport using carbon 14 and strontium 90 as inert tracers

    Science.gov (United States)

    Kinnison, D. E.; Johnston, H. S.; Wuebbles, D. J.

    1994-10-01

    The observed excess carbon 14 in the atmosphere from 1963 to 1970 provides unique, but limited, data up to an altitude of about 35 km for testing the air motions calculated by 11 multidimensional atmospheric models. Strontium 90 measurements in the atmosphere from 1964 to mid-1967 provide data that have more latitude coverage than those of carbon 14 and are useful for testing combined models of air motions and aerosol settling. Model calculations for carbon 14 begin at October 1963, 9 months after the conclusion of the nuclear bomb tests; the initial conditions for the calculations are derived by three methods, each of which agrees fairly well with measured carbon 14 in October 1963 and each of which has widely different values in regions of the stratosphere where there were no carbon 14 measurements. The model results are compared to the stratospheric measurements, not as if the observed data were absolute standards, but in an effort to obtain new insight about the models and about the atmosphere. The measured carbon 14 vertical profiles at 31°N are qualitatively different from all of the models; the measured vertical profiles show a maximum mixing ratio in the altitude range of 20 to 25 km from October 1963 through July 1966, but all modeled profiles show mixing ratio maxima that increase in altitude from 20 km in October 1963 to greater than 40 km by April 1966. Both carbon 14 and strontium 90 data indicate that the models differ substantially among themselves with respect to stratosphere-troposphere exchange rate, but the modeled carbon 14 stratospheric residence times indicate that differences among the models are small with respect to transport rate between the middle stratosphere and the lower stratosphere. Strontium 90 data indicate that aerosol settling is important up to at least 35 km altitude. Relative to the measurements, about three quarters of the models transport carbon 14 from the lower stratosphere to the troposphere too rapidly, and all models

  4. Behavior of environmental carbon-14 and tritium in Japan

    International Nuclear Information System (INIS)

    Iwakura, T.; Kasida, Y.; Inoue, Y.; Tanaka, K.; Arai, K.

    1979-01-01

    The 14 C activity in plants began to rise appreciably above normal in 1957, and the level rose almost linearly with the rate of 7% per year to the level in 1959. Steep increase of the level to a peak in 1963, between 85% and 90% above normal, shows the effect of large scale nuclear explosions through the end of 1962. Liquid scintillation counting was used as a sensitive assay method of 14 C and 3 H. For 14 C determination, the naturally incorporated 14 C into alcohol and essential oils (thymol, menthol and lemongrass oil) and used, and water samples were used for 3 H measurement. The total amount 65 x 10 27 of 14 C atoms has been produced in nuclear tests, and this amount is about 3% of the total amount of 14 C in nature. The 3 H concentration in rivers, streams and ponds decreased exponentially from 600 pCi/l in 1967 to 150 pCi/l in 1972, with the half life of 2.5yr. The difference of the 3 H concentration in surface water according to the sampling locations implies geographical and meteorological variations in fallout 3 H level. It is said conclusively that environmental waters in Japan have not been influenced by the discharge effluent of the facilities with regard to tritium contamination and that tritium content in precipitation still play an important role in reflecting annual variation of tritium concentration to surface waters. (J.P.N.)

  5. Determination of 14C age of inorganic and organic carbon in ancient Siberian permafrost

    Science.gov (United States)

    Onstott, T. C.; Liang, R.; Lau, M.; Vishnivetskaya, T. A.; Lloyd, K. G.; Pfiffner, S. M.; Hodgins, G.; Rivkina, E.

    2017-12-01

    Permafrost represents a large reservoir of ancient carbon that could have an important impact on the global carbon budget during climate warming. Due to the low turnover rate of carbon by microorganisms at subzero temperatures, the persistence of ancient carbon in younger permafrost deposits could also pose challenges for radiocarbon dating of permafrost sediment. We utilized Accelerator Mass Spectrometry to determine the 14C age of inorganic carbon, labile and recalcitrant organic carbon in Siberian permafrost sediment sampled at various depths from 2.9 to 5.6m. The fraction of inorganic carbon (CO2) was collected after acidification using phosphoric acid. The labile (younger) and recalcitrant (old) organic carbon in the subsequent residues were collected after combustion at 400 ºC and 800 ºC, respectively. The percentages of inorganic carbon increased from the youngest (2.9m) to the oldest (5.6m), whereas the fractions for organic carbon varied significantly at different depths. The 14C age determined in the inorganic fraction in the top sample (2.9 m) was 21,760 yr BP and gradually increased to 33,900 yr BP in the relative deeper sediment (3.5 and 5.6 m). Surprisingly, the fraction of "younger" carbon liberated at 400 oC was older than the more recalcitrant and presumably older organic carbon liberated at 800 oC in all cases. Moreover, the 14C age of the younger and older organic carbon fractions did not increase with depth as observed in the carbonate fraction. In particular, the 14C age of the organic carbon in the top sample (38,590-41,700 yr BP) was much older than the deeper samples at depth of 3.5m (18,228-20,158 yr BP) and 5.6m (29,040-38,020 yr BP). It should be noticed that the metabolism of ancient carbon in frozen permafrost may vary at different depths due to the different proportion of necromass and metabolically active microbes. Therefore, additional knowledge about the carbon dynamics of permafrost and more investigation would be required to

  6. Biogenic Carbon Fraction of Biogas and Natural Gas Fuel Mixtures Determined with 14C

    NARCIS (Netherlands)

    Palstra, Sanne W. L.; Meijer, Harro A. J.

    2014-01-01

    This study investigates the accuracy of the radiocarbon-based calculation of the biogenic carbon fraction for different biogas and biofossil gas mixtures. The focus is on the uncertainty in the C-14 reference values for 100% biogenic carbon and on the C-13-based isotope fractionation correction of

  7. Carbon 14 absorption and translocation in sugar cane

    International Nuclear Information System (INIS)

    Pimentel, R.M.M.; Sampaio, E.V.S.; Salcedo, I.H.

    1990-01-01

    Plant-cane stools were labelled with sup(14) CO sub(2), in the field, at Goiana-PE, Brazil, when 3, 7 and 11 months old. Each stool was enclosed in a chamber with sup(14) CO sub(2) for 90 minutes. The sub(14) C photosynthetic were measured in leaves, stalks, roots and soil 24 hours after labelling. Roots were divided into alive and dead and soil into rhizosphere and outer soil. At the end of the labelling period at 3, 7 and 11 months, 2, 19 and 1% of the initial sup(14) CO sub(2) were recovered in the plant and the soil. The low recovery of sub(14) C at 3 months could be attribute to losses by respiration and lack of sampling of the top growing point. The low CO sub(2) fixation and losses at first sampling in the 7 month old labelling were attributed to low light intensity during the day of labelling. Most of the recovered sub(14) C (>80%) was founded in the leaves but all plant parts received labelled photosynthetic. At 3 months, most of the sub(14) C translocated from the leaves went to the living roots (83%); at 7 and 11 months it went to the stalks (69 and 66%). While the roots received less than 2%. Root masses did not vary consistently along the plant cycle and dead root masses were always less than 10% of the total root mass. Radioactivity in the dead roots was always very low. These results suggest that the root system have a low turnover rate after 3 months old. (author)

  8. Results of interagency effort to determine carbon-14 source term in low-level radioactive waste

    International Nuclear Information System (INIS)

    Gruhlke, J.M.; Meyer, G.L.; Neiheisel, J.

    1987-01-01

    A preliminary estimate of the risks from the shallow land disposal of low-level radioactive wastes by EPA in 1984-1985 indicated that Carbon-14 caused virtually all of the risk and that these risks were relatively high. Therefore, an informal interagency group, which included the US Department of Energy, US Geological Survey, US Nuclear Regulatory Commission, and US Environmental Protection Agency, formed in 1985 to obtain up-to-date information on the activity and chemical form of Carbon-14 in the different types of LLW and how Carbon-14 behaves after disposal. The EPA acted as a focal point for collating the information collected by all of the Agencies and will publish a report in Fall 1986 on the results of the Carbon-14 data collection effort. Of particular importance, the study showed that Carbon-14 activity in LLW was overestimated approximately 2000%. This paper summarizes results of the Carbon-14 data collection effort. 40 references, 1 figure, 3 tables

  9. Estimating the Contribution of Industry Structure Adjustment to the Carbon Intensity Target: A Case of Guangdong

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2016-04-01

    Full Text Available Industry structure adjustment is an effective measure to achieve the carbon intensity target of Guangdong Province. Accurately evaluating the contribution of industry structure adjustment to the carbon intensity target is helpful for the government to implement more flexible and effective policies and measures for CO2 emissions reduction. In this paper, we attempt to evaluate the contribution of industry structure adjustment to the carbon intensity target. Firstly, we predict the gross domestic product (GDP with scenario forecasting, industry structure with the Markov chain model, CO2 emissions with a novel correlation mode based on least squares support vector machine, and then we assess the contribution of industry structure adjustment to the carbon intensity target of Guangdong during the period of 2011–2015 under nine scenarios. The obtained results show, in the ideal scenario, that the economy will grow at a high speed and the industry structure will be significantly adjusted, and thus the carbon intensity in 2015 will decrease by 25.53% compared to that in 2010, which will make a 130.94% contribution to the carbon intensity target. Meanwhile, in the conservative scenario, the economy will grow at a low speed and the industry structure will be slightly adjusted, and thus the carbon intensity in 2015 will decrease by 23.89% compared to that in 2010, which will make a 122.50% contribution to the carbon intensity target.

  10. Synthesis of a polycyclic aromatic hydrocarbon marked with carbon-14: (b, d e f) dibenzo-chrysene 14C-7,14

    International Nuclear Information System (INIS)

    Chatelain, G.

    1965-01-01

    (b, d e f) dibenzo-chrysene C-7,14 has been synthesized from radioactive carbon dioxide and the organic magnesium compound derived from 1,5 dibromo naphthalene. The product has been purified by a very precise series of fractionated chromatographs on alumina having a chromatographic activity. This has necessitated the development of a special technique. (author) [fr

  11. Target vs. background discrimination using multispectral data in 1.5-14.5 micron

    Science.gov (United States)

    Cogliandro, Santo; Panizza, Marco; Castelli, Paola

    1987-01-01

    LOWTRAN V model calculations are compared to experimental spectral background radiance and spectral transmittance data in the 1.5 to 14.5-micron band, in order to identify the most important parameters affecting the discrimination of targets from background. Attention is accordingly given to the IR energy emitted by a reference plate at different values of temperature and emissivity vs various previously investigated backgrounds. Targets at near-ambient temperature are also considered.

  12. Carbon-14 as an indicator of CO2 pollution in cities

    International Nuclear Information System (INIS)

    Vogel, J.C.; Uhlitzsch, I.

    1975-01-01

    The combustion of fossil fuels in cities, and especially in industrial areas, releases large quantities of carbon dioxide into the local atmosphere. This carbon dioxide does not contain carbon-14, with the result that the carbon-14 content of the atmospheric carbon dioxide is locally depleted. The degree of depletion provides a measure for the carbon dioxide pollution at the sampling site. Since growing plants represent a convenient average sample of the carbon dioxide in the air, the leaves of deciduous trees can be used for comparing the magnitude of local pollution in different localities during the summer growing period. A series of leaf samples collected in 1973 from Europe, North America and South Africa reveals the expected differences in the degree of pollution. Extreme instances occur in Scholven (Ruhrgebiet, Germany), where the average day-time carbon dioxide content during the summer months is found to be 8.7% above normal, and in Manhatten, New York City, where the corresponding figure is 6.4%. The technique can easily be extended to include the winter months by directly absorbing carbon dioxide in a hydroxide solution during different seasons. The proposed method is sensitive but much less time-consuming than the continuous measurement of the carbon dioxide concentration in the air. It thus lends itself to the monitoring of impact areas of pollution. (author)

  13. Secular variations in carbon-14 and their geophysical implications

    CSIR Research Space (South Africa)

    Vogel

    2002-03-01

    Full Text Available . The identification of the causes and magnitudes of these deviations has created a new too that is contributing to the investigation of different geophysical: phenomena. Variations in the activity of the Sun produce fluctuations of the C-14 level in the atmosphere...

  14. Carbon -14 labelling of terbinafine, an antimycotic agent

    Energy Technology Data Exchange (ETDEWEB)

    Andres, H. (Sandoz Ltd., Basel (Switzerland). Isotope Div.)

    1989-11-01

    Terbinafine is a new antimycotic agent which is currently being tested worldwide in clinical trials. The synthesis of ({sup 14}C)Terbinafine, labelled in the naphthalene methane moiety as well as in the tertiary butyl group is described. The key step of the latter is the aluminium-mediated tertiary butylation of an alkyne. (author).

  15. Carbon -14 labelling of terbinafine, an antimycotic agent

    International Nuclear Information System (INIS)

    Andres, H.

    1989-01-01

    Terbinafine is a new antimycotic agent which is currently being tested worldwide in clinical trials. The synthesis of [ 14 C]Terbinafine, labelled in the naphthalene methane moiety as well as in the tertiary butyl group is described. The key step of the latter is the aluminium-mediated tertiary butylation of an alkyne. (author)

  16. Immobilization of carbon 14 contained in spent fuel hulls through melting-solidification treatment

    International Nuclear Information System (INIS)

    Mizuno, T.; Maeda, T.; Nakayama, S.; Banba, T.

    2004-01-01

    The melting-solidification treatment of spent nuclear fuel hulls is a potential technique to improve immobilization/stabilization of carbon-14 which is mobile in the environment due to its weakly absorbing properties. Carbon-14 can be immobilized in a solid during the treatment under an inert gas atmosphere, where carbon is not oxidized to gaseous form and remains in the solid. A series of laboratory scale experiments on retention of carbon into an alloy waste form was conducted. Metallic zirconium was melted with metallic copper (Zr/Cu=8/2 in weight) at 1200 deg C under an argon atmosphere. Almost all of the carbon remained in the resulting zirconium-copper alloy. (authors)

  17. Atmospheric nuclear weapons test history narrated by carbon-14 in human teeth

    International Nuclear Information System (INIS)

    Nishizawa, Kunihide; Nagatsu, Toshiharu; Togari, Akifumi; Matsumoto, Shosei

    1991-01-01

    The atmospheric testing of nuclear weapons since 1945 caused a significant increase in the concentration of atmospheric 14 C. The 14 C concentration in plants that assimilate 14 C directly by photosynthesis reflects the atmospheric 14 C concentration. Carbon-14 is then transferred into the human body through the food chain. Based on animal experiments, the collagen in human teeth is metabolically inert after its formation. This implies that the collagen of each tooth retains the 14 C concentration which reflects the 14 C concentration in the blood at the time collagen metabolism ceased. The distribution of the 14 C concentration in the collagen of teeth from subjects of various ages would follow a pattern similar to that shown by soft tissues. In this paper the authors elucidate the relationship between the number of nuclear weapon tests and the distribution of 14 C concentration in teeth

  18. Determination of carbon-14 in environmental level, solid reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Blowers, Paul, E-mail: paul.blowers@cefas.co.uk [Cefas Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk, NR33 0HT (United Kingdom); Caborn, Jane, E-mail: jane.a.caborn@nnl.co.uk [NNL, Springfields, Salwick, Preston, Lancashire, PR4 0XJ (United Kingdom); Dell, Tony [Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT15 3NB (United Kingdom); Gingell, Terry [DSTL, Radiation Protection Services, Crescent Road, Alverstoke, Gosport, Hants, PO12 2DL (United Kingdom); Harms, Arvic [National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Long, Stephanie [Radiological Protection Institute of Ireland, 3 Clonskeagh Square, Clonskeagh Road, Dublin 14, Ireland (United Kingdom); Sleep, Darren [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Stewart, Charlie [UKAEA (Waste Management Group), Chemical Support Services, D1310/14, Dounreay, Thurso, Caithness, KW14 7TZ (United Kingdom); Walker, Jill [Radiocarbon Dating, The Old Stables, East Lockinge, Wantage, Oxon OX12 8QY (United Kingdom); Warwick, Phil E. [GAU-Radioanalytical, National Oceanography Centre Southampton, European Way, Southampton, SO14 3ZH (United Kingdom)

    2011-10-15

    An intercomparison exercise to determine the {sup 14}C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing {sup 14}C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

  19. Displacement of carbon-14 labelled amino acids from leaves

    International Nuclear Information System (INIS)

    Schiller, R.

    1973-01-01

    The displacement of amino acids from nature leaves was investigated. The amino acids (Ala, Asn, Asp, Glu, Gln, Val, Leu, Lys, Ser, Pro) were applied on the leaves in L-form, uniformly labelled with 14 C, and the type and direction of displacement have been observed. Most of the studies have been carried out on bush beans aged 3 to 4 weeks. The experiments were carried out in climatic chambers; in one case, barley plants just reaching maturity were used. In order to find out whether the applied amino acids were also displaced in their original form, freeze-dried plants were extracted and the 14 C activity of the various fraction was determined. The radioactivity of some free amino acids was determined after two-dimensional separation by thin film chromatography. (orig./HK) [de

  20. Determination of carbon-14 in environmental level, solid reference materials

    International Nuclear Information System (INIS)

    Blowers, Paul; Caborn, Jane; Dell, Tony; Gingell, Terry; Harms, Arvic; Long, Stephanie; Sleep, Darren; Stewart, Charlie; Walker, Jill; Warwick, Phil E.

    2011-01-01

    An intercomparison exercise to determine the 14 C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing 14 C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

  1. Low carbon and clean energy scenarios for India: Analysis of targets approach

    International Nuclear Information System (INIS)

    Shukla, Priyadarshi R.; Chaturvedi, Vaibhav

    2012-01-01

    Low carbon energy technologies are of increasing importance to India for reducing emissions and diversifying its energy supply mix. Using GCAM, an integrated assessment model, this paper analyzes a targets approach for pushing solar, wind, and nuclear technologies in the Indian electricity generation sector from 2005 to 2095. Targets for these technologies have been constructed on the basis of Indian government documents, policy announcements, and expert opinions. Different targets have been set for the reference scenario and the carbon price scenario. In the reference scenario, wind and nuclear technologies exceed respective targets in the long run without any subsidy push, while solar energy requires subsidy push throughout the century in order to meet its high targets. In the short run, nuclear energy also requires significant subsidy, including a much higher initial subsidy relative to solar power, which is a result of its higher targets. Under a carbon price scenario, the carbon price drives the penetration of these technologies. Still, subsidy is required — especially in the short run when the carbon price is low. We also found that pushing solar, wind, and nuclear technologies leads to a decrease in share of CCS under the carbon price scenario and biomass under both the reference and carbon price scenarios. This is because low carbon technologies compete among themselves and substitute each other, thereby enhancing the need for subsidy or carbon price, highlighting that proposed targets are not set at efficient levels. In light of contemporary debate on external costs of nuclear energy, we also assess the sensitivity of the results to nuclear technology cost. We find that higher cost significantly decreases the share of nuclear power under both the reference and carbon price scenarios.

  2. A novel llama antibody targeting Fn14 exhibits anti-metastatic activity in vivo.

    Science.gov (United States)

    Trebing, Johannes; Lang, Isabell; Chopra, Martin; Salzmann, Steffen; Moshir, Mahan; Silence, Karen; Riedel, Simone S; Siegmund, Daniela; Beilhack, Andreas; Otto, Christoph; Wajant, Harald

    2014-01-01

    Expression of fibroblast growth factor (FGF)-inducible 14 (Fn14), a member of the tumor necrosis factor receptor superfamily, is typically low in healthy adult organisms, but strong Fn14 expression is induced in tissue injury and tissue remodeling. High Fn14 expression is also observed in solid tumors, which is why this receptor is under consideration as a therapeutic target in oncology. Here, we describe various novel mouse-human cross-reactive llama-derived recombinant Fn14-specific antibodies (5B6, 18D1, 4G5) harboring the human IgG1 Fc domain. In contrast to recombinant variants of the established Fn14-specific antibodies PDL192 and P4A8, all three llama-derived antibodies efficiently bound to the W42A and R56P mutants of human Fn14. 18D1 and 4G5, but not 5B6, efficiently blocked TNF-like weak inducer of apoptosis(TWEA K) binding at low concentrations (0.2–2 μg/ml). Oligomerization and Fcγ receptor (FcγR) binding converted all antibodies into strong Fn14 agonists. Variants of 18D1 with enhanced and reduced antibody-dependent cell-mediated cytotoxicity (ADCC) activity were further analyzed in vivo with respect to their effect on metastasis. In a xenogeneic model using human colon carcinoma cancer cells, both antibody variants were effective in reducing metastasis to the liver. In contrast, only the 18D1 variant with enhanced ADCC activity, but not its ADCC-defective counterpart, suppressed lung metastasis in the RE NCA model. In sum, this suggests that Fn14 targeting might primarily act by triggering of antibody effector functions, but also by blockade of TWEA K-Fn14 interaction in some cases

  3. Synthesis of canrenone and related steroids labelled with tritium, carbon-14, and sulfur-35

    International Nuclear Information System (INIS)

    Markos, C.S.; Dorn, C.R.; Zitzwitz, D.J.

    1988-01-01

    The syntheses of [1- 3 H]canrenone, [1- 3 H]spironolactone, [1- 3 H] potassium canrenoate, [22- 14 C]canrenone, [22- 14 C]spironolactone, [22- 14 C]potassium canrenoate, and [ 35 S]spironolactone are reported. Tritium labelled compounds were obtained by catalytic reduction of a 3-keto-1, 4-diene precursor followed by exchange of enolizable label. Carbon-14 compounds were obtained by reaction of a 17-ethynyl steroid with 14 CO 2 . Sulfur-35 spironolactone was synthesized by the in-situ generation of [ 35 S]thiolacetic acid from [ 35 S]sodium sulfide. (author)

  4. Distribution of Δ14C in western North Pacific and tracing carbons of human origin

    International Nuclear Information System (INIS)

    Aramaki, Takafumi; Mizushima, Toshihiko; Togawa, Orihiko; Kuji, Tomoyuki

    2001-01-01

    Seawater were collected at six points, 0deg to 48degN around 165degE. Dissolved inorganic carbonates was reduced into graphite. The ratio C-11/C-12 was measured by the accelerator mass analyzer. 14 C concentration was calculated from δ 13 C value calculated from the 13 C/ 12 C ratio. 14 C resulting from the nuclear weapon test was calculated by comparing estimated 14 C and real 14 C concentration. It was compared with that in 1970s. 14 Cbomb has dissolved into North Pacific Intermediate Water in Arctic latitude, which has moved to Mid-latitude. (A. Yamamoto)

  5. Characteristics study of a system for carbon 14 dating

    International Nuclear Information System (INIS)

    Oikawa, H.

    1978-01-01

    The developing of a radiocarbon dating laboratory, specially built to deal with carbonate samples from underground water, at the Institute de Energia Atomica, required the optimization of a benzene synthetizer, and also of the operative conditions of the liquid scintillator counter, used in sample measurements. An average yield of about 70% was obtained in our benzenic synthesis. If more refined conditions were used, better results could have been obtained, but the reported yield is good enough for our necessities. A comparison of the ages of several shell samples was done between the Geochronology Laboratory, belonging to the Instituto de Geociencias, at Sao Paulo University and our dating laboratory. The agreement between the results was fairly good, according to the precision required [pt

  6. Carbon-14 behavior in a cement-dominated environment: Implications for spent CANDU resin waste disposal

    International Nuclear Information System (INIS)

    Dayal, R.; Reardon, E.J.

    1994-01-01

    Cement based waste forms and concrete engineered barriers are expected to play a key role in providing 14 C waste containment and control 14 C migration for time periods commensurate with its hazardous life of about 50,000 years. The main thrust of this study was, therefore, to evaluate the performance of cement based waste forms with regard to 14 C containment. Of particular importance are the geochemical processes controlling 14 C solubility and release under anticipated cement dominated low and intermediate level waste repository conditions. Immobilization of carbonate-form exchange resin in grout involves transfer of sorbed 14 CO 3 2- ions, through exchange for hydroxyl ions from the grout slurry, followed by localized precipitation of solid calcium carbonate at the cement/resin interface in the grout matrix. Carbon-14 release behavior can be attributed to the dissolution characteristics and solubility of calcite present in the cement based waste form. The groundwater flow regime can exert a pronounced effect both on the near-field chemistry and the leaching behavior of 14 C. For a cement dominated repository, at relatively low-flow or stagnant groundwater conditions, the alkaline near-field chemical environments inhibits the release of 14 C from the cemented waste form. Under high flow conditions, the near-field environment is characterized by relatively neutral pH conditions which promote calcite dissolution, thus resulting in 14 C release from the waste form

  7. Removal of target odorous molecules on to activated carbon cloths.

    Science.gov (United States)

    Le Leuch, L M; Subrenat, A; Le Cloirec, P

    2004-01-01

    Activated carbon materials are adsorbents whose physico-chemical properties are interesting for the treatment of odorous compounds like hydrogen sulfide. Indeed, their structural parameters (pore structure) and surface chemistry (presence of heteroatoms such as oxygen, hydrogen, nitrogen, sulfur, phosphorus) play an important role in H2S removal. The cloth texture of these adsorbents (activated carbon cloths) is particularly adapted for dealing with high flows, often found in the treatment of odor emissions. Thus, this paper first presents the influence of these parameters through adsorption isothermal curves performed on several materials. Secondly, tests in a dynamic system are described. They highlight the low critical thickness of the fabric compared to granular activated carbon.

  8. Precision of Carbon-14 analysis in a single laboratory

    International Nuclear Information System (INIS)

    Nashriyah Mat; Misman Sumin; Holland, P.T.

    2009-01-01

    In a single laboratory, one operator has used a Biological Material Oxidizer (BMO) unit to prepare (combust) solid samples before analyzing (counting) the radioactivity by using various Liquid Scintillation Counters (LSCs). The different batches of commercially available solid Certified Reference Material (CRM, Amersham, UK) standards were analyzed depending on the time of analysis over a period of seven years. The certified radioactivity and accuracy of the C-14 standards as cellulose tabs, designated as the Certified Reference Material (CRM), was 5000 + 3% DPM. Each analysis was carried out using triplicate tabs. The medium of counting was commercially available cocktail containing the sorbent solution for the oxidizer gases, although of different batches were used depending on the date of analysis. The mean DPM of the solutions was measured after correction for quenching by the LSC internal standard procedure and subtracting the mean DPM of control. The precisions of the standard and control counts and of the recovery percentage for the CRM were measured as the coefficients of variation (CV), for the C-14 determination over the seven year period. The results from a recently acquired Sample Oxidizer unit were also included for comparison. (Author)

  9. Carbon-14 releases from an unsaturated repository: A senseless but expensive dilemma

    International Nuclear Information System (INIS)

    Pflum, C.G.

    1993-01-01

    The purpose of the US Environmental Protection Agency (EPA) Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR Part 191 or standards) is to protect public health and safety. The 1985 rule was developed on the basis of the assumption that the repository would be located in a geologic formation that lies below the water table. It is appropriate to examine gaseous releases and transport of pollutants in order to determine site adequacy. When the provisions of the 1985 standard are applied to Yucca Mountain, specifically the limits for carbon-14, we can release in 10,000 years no more than 7,000 curies of carbon-14 in the form of carbon dioxide. Meanwhile, the US Department of Energy (DOE) and others indicate that the repository may release about 8,000 curies of carbon-14 dioxide, an amount that exceeds the standard by 10 to 20 percent. The original basis of the 1985 standards was that, in a site below the water table, the limit for carbon-14 was technically achievable. It was not a standard based on a release level that would prevent a danger to public health. If we examine the danger to public health of the release of 8,000 curies of carbon-14 dioxide during and 8,000-year period, this release would not a pose a significant threat to the average individual. Industry and natural sources release many times this amount of carbon-14 dioxide each year. The question therefore becomes: is it appropriate to spend an additional $3.2 billion on waste packages when the expenditure does not measurably improve the public health?

  10. Determination of Carbon-14 in environmental samples by mixing 14CO{sub 2} with a liquid scintillator; Determinacion de carbono-14 en muestras ambientales por incorporacion de 14CO{sub 2} a un centelleador liquido

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. R.; Gomez, V.; Heras, M. C.; Beltran, M. A.

    1990-07-01

    A method for the determination of Carbon-14 (14CO2) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO2) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discussed and compared. The method of collection of atmospheric samples is also described. (Author) 10 refs.

  11. Two dimensional model study of atmospheric transport using carbon-14 and strontium-90 as inert tracers

    International Nuclear Information System (INIS)

    Kinnison, D.E.; Wuebbles, D.J.; Johnston, H.S.

    1992-02-01

    This study tests the transport processes in the LLNL two-dimensional chemical-radiative-transport model using recently reanalyzed carbon-14 and strontium-90 data. These radioactive tracers were produced bythe atmospheric nuclear bomb tests of 1952--58 and 1961--62, and they were measured at a few latitudes up to 35 kilometers over the period 1955--1970. Selected horizontal and vertical eddy diffusion coefficients were varied in the model to test their sensitivity to short and long term transpose of carbon-14. A sharp transition of K zz and K yy through the tropopause, as opposed to a slow transition between the same limiting values, shows a distinct improvement in the calculated carbon-14 distributions, a distinct improvement in the calculated seasonal and latitudinal distribution of ozone columns (relative to TOMS observations), and a very large difference in the calculated ozone reduction by a possible fleet of High Speed Civil Transports. Calculated northern hemisphere carbon-14 is more sensitive to variation of K yy than are global ozone columns. Strontium-90 was used to test the LLNL tropopause height at four different latitudes. Starting with the 1960 background distribution of carbon-14, we calculate the input of carbon-14 as the sum of each nuclear test of the 1961--62 series, using two bomb-cloud rise models. With the Seitz bomb-rise formulation in the LLNL model, we find good agreement between calculated and observedcarbon-14 (with noticeable exceptions at the north polar tropopause and the short-term mid-latitude mid-stratosphere) between 1963 and 1970

  12. Switching transport modes to meet voluntary carbon emission targets

    NARCIS (Netherlands)

    Hoen, K.M.R.; Tan, T.; Fransoo, J.C.; Houtum, van G.J.J.A.N.

    2014-01-01

    The transport sector is the second largest carbon emissions contributor in Europe and its emissions continue to increase. Many producers are committing themselves to reducing transport emissions voluntarily, possibly in anticipation of increasing transport prices. In this paper we study a producer

  13. Switching transport modes to meet voluntary carbon emission targets

    NARCIS (Netherlands)

    Hoen, K.M.R.; Tan, T.; Fransoo, J.C.; Houtum, van G.J.J.A.N.

    2011-01-01

    The transport sector is the second largest carbon emissions contributor in Europe and its emissions continue to increase. Many shippers are committing themselves to reducing transport emissions voluntarily, possibly in anticipation of increasing transport prices. In this paper we study a shipper

  14. Fate of gaseous tritium and carbon-14 released from buried low-level radioactive waste

    International Nuclear Information System (INIS)

    Striegl, R.G.

    1988-01-01

    Microbial decomposition, chemical degradation, and volatilization of buried low-level radioactive waste results in the release of gases containing tritium ( 3 H) and carbon-14 ( 14 C) to the surrounding environment. Water vapor, carbon dioxide, and methane that contain 3 H or 14 C are primary products of microbial decomposition of the waste. Depending on the composition of the waste source, chemical degradation and volatilization of waste also may result in the production of a variety of radioactive gases and organic vapors. Movement of the gases in materials that surround waste trenches is affected by physical, geochemical, and biological mechanisms including sorption, gas-water-mineral reactions, isotopic dilution, microbial consumption, and bioaccumulation. These mechanisms either may transfer 3 H and 14 C to solids and infiltrating water or may result in the accumulation of the radionuclides in plant or animal tissue. Gaseous 3 H or 14 C that is not transferred to other forms is ultimately released to the atmosphere

  15. Compositions and methods for cancer treatment using targeted carbon nanotubes

    Science.gov (United States)

    Harrison, Jr., Roger G; Resasco, Daniel E; Neves, Luis Filipe Ferreira

    2013-08-27

    The present invention is a method for detecting and destroying cancer tumors. The method is based on the concept of associating a linking protein or linking peptide such as, but not limited to, annexin V or other annexins to carbon nanotubes such as single-walled carbon nanotubes (SWNTs) to form a protein-CNT complex. Said linking protein or peptide can selectively bind to cancerous cells, especially tumor vasculature endothelial cells, rather than to healthy ones by binding to cancer-specific external receptors such as anionic phospholipids including phosphatidylserine expressed on the outer surfaces of cancer cells only. Irradiation of bound CNTs with one or more specific electromagnetic wavelengths is then used to detect and destroy those cells to which the CNTs are bound via the linking protein or peptide thereby destroying the tumor or cancer cells and preferably an immunostimulant is provided to the patient to enhance the immune response against antigens released from the tumor or cancer cells.

  16. Study of a method of detection for natural carbon-14 using a liquid scintillator, recent variations in the natural radio-activity due to artificial carbon-14 (1963); Etude d'une methode de detection du carrons 14 naturel, utilisant un scintillateur liquide - variations recentes de l'activite naturelle dues au carbone 14 artificiel (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Leger, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-06-15

    Among the various natural isotopes of carbon, a radioactive isotope, carbon-14, is formed by the action of secondary neutrons from cosmic rays on nitrogen in the air. Until 1950, the concentration of this isotope in ordinary carbon underwent weak fluctuations of about 2-3 per cent. The exact measurement of this concentration 6 X 10{sup 12} Ci/gm of carbon, and of its fluctuations, are difficult and in the first part of this report a highly sensitive method is given using a liquid scintillator. Since 1950 this natural activity has shown large fluctuations because of the carbon-14 formed during nuclear explosions, and in the second part, the evolution in France of this specific activity of carbon in the atmosphere and biosphere is examined. In the last part is studied the local increase in carbon activity in the atmosphere around the Saclay site, an increase caused by the carbon-14 given off as C{sup 14}O{sub 2}, by the reactors cooled partially with exterior air. (author) [French] Parmi les differents isotopes naturels du carbone, un isotope radioactif, le carbone 14, est forme par l'action de neutrons secondaires due aux rayons cosmiques sir l'azote de l'air. Jusqu'en 1950, la concentration de cet isotope dans le carbone ordinaire est soumise a des fluctuations de faible amplitude, de l'ordre de 2 a 3 pour cent. Les mesures precises de cette concentration, 6. 10{sup -12} Ci/g de carbone, et de ses fluctuations sont delicates, et dans la premiere partie de ce rapport, on decrit une methode de detection a grande sensibilite utilisant un scintillateur liquide. Depuis 1950, cette activite naturelle subit des fluctuations importantes dues au carbone 14 forme lors des explosions nucleaires, et dans la seconde partie, on examine l'evolution en France de l'activite specifique du carbone de l'atmosphere et ce la biosphere. Dans la derniere partie, on etudie l'accroissement local de l'activite du carbone de l'air aux environs du site de Saclay, accroissement provoque par le

  17. Study of a method of detection for natural carbon-14 using a liquid scintillator, recent variations in the natural radio-activity due to artificial carbon-14 (1963); Etude d'une methode de detection du carrons 14 naturel, utilisant un scintillateur liquide - variations recentes de l'activite naturelle dues au carbone 14 artificiel (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Leger, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-06-15

    Among the various natural isotopes of carbon, a radioactive isotope, carbon-14, is formed by the action of secondary neutrons from cosmic rays on nitrogen in the air. Until 1950, the concentration of this isotope in ordinary carbon underwent weak fluctuations of about 2-3 per cent. The exact measurement of this concentration 6 X 10{sup 12} Ci/gm of carbon, and of its fluctuations, are difficult and in the first part of this report a highly sensitive method is given using a liquid scintillator. Since 1950 this natural activity has shown large fluctuations because of the carbon-14 formed during nuclear explosions, and in the second part, the evolution in France of this specific activity of carbon in the atmosphere and biosphere is examined. In the last part is studied the local increase in carbon activity in the atmosphere around the Saclay site, an increase caused by the carbon-14 given off as C{sup 14}O{sub 2}, by the reactors cooled partially with exterior air. (author) [French] Parmi les differents isotopes naturels du carbone, un isotope radioactif, le carbone 14, est forme par l'action de neutrons secondaires due aux rayons cosmiques sir l'azote de l'air. Jusqu'en 1950, la concentration de cet isotope dans le carbone ordinaire est soumise a des fluctuations de faible amplitude, de l'ordre de 2 a 3 pour cent. Les mesures precises de cette concentration, 6. 10{sup -12} Ci/g de carbone, et de ses fluctuations sont delicates, et dans la premiere partie de ce rapport, on decrit une methode de detection a grande sensibilite utilisant un scintillateur liquide. Depuis 1950, cette activite naturelle subit des fluctuations importantes dues au carbone 14 forme lors des explosions nucleaires, et dans la seconde partie, on examine l'evolution en France de l'activite specifique du carbone de l'atmosphere et ce la biosphere. Dans la derniere partie, on etudie l'accroissement local de l'activite du carbone de l'air aux

  18. Proportion of biogenic carbon in flue gas by carbon-14 measurement; Biohiili2: Biohiilen mittaus savukaasusta hiili-14-menetelmaellae

    Energy Technology Data Exchange (ETDEWEB)

    Lehtomaeki, J.; Antson, O.; Hongisto, M.; Knuuttila, M.; Roine, J.; Raesaenen, J.; Tormonen, K. [VTT Technical Research Centre of Finland, Espoo (Finland); Jungner, H. [Helsinki Univ. (Finland)

    2007-07-01

    The subject of this project is closely related to EU's emissions trading system and to the current and future monitoring needs therein. The determination of fossil part of emissions originated from various fuels by stack measurements or by laboratory analyses could possibly find users also in other fields outside the ETS (e.g. waste incineration). After the market analysis and preliminary measurements carried out in the previous Biocarbon project this project focused on the development of the sampling method for stack measurements and to the validation of isotope measurements. The results obtained for fossil proportion of the fuel by current methods will be compared to those obtained by isotope measurements. The operation of the sampling system was tested in long period tests in plant conditions. Moreover, the sample preparation methods and isotope measurements were validated by measuring the proportions of biogenic and fossil carbon of known traffic fuel mixtures. The developed service concept can also be utilised as a fraud prevention measure related to the expanding international biofuels-trade. (orig.)

  19. The synthesis of a tritium, carbon-14, and stable isotope-labeled cathepsin C inhibitors.

    Science.gov (United States)

    Allen, Paul; Bragg, Ryan A; Caffrey, Moya; Ericsson, Cecilia; Hickey, Michael J; Kingston, Lee P; Elmore, Charles S

    2017-02-01

    As part of a medicinal chemistry program aimed at developing a highly potent and selective cathepsin C inhibitor, tritium, carbon-14, and stable isotope-labeled materials were required. The synthesis of tritium-labeled methanesulfonate 5 was achieved via catalytic tritiolysis of a chloro precursor, albeit at a low radiochemical purity of 67%. Tritium-labeled AZD5248 was prepared via a 3-stage synthesis, utilizing amide-directed hydrogen isotope exchange. Carbon-14 and stable isotope-labeled AZD5248 were successfully prepared through modifications of the medicinal chemistry synthetic route, enabling the use of available labeled intermediates. Copyright © 2016 John Wiley & Sons, Ltd.

  20. The PTPN14 Tumor Suppressor Is a Degradation Target of Human Papillomavirus E7.

    Science.gov (United States)

    Szalmás, Anita; Tomaić, Vjekoslav; Basukala, Om; Massimi, Paola; Mittal, Suruchi; Kónya, József; Banks, Lawrence

    2017-04-01

    Activation of signaling pathways ensuring cell growth is essential for the proliferative competence of human papillomavirus (HPV)-infected cells. Tyrosine kinases and phosphatases are key regulators of cellular growth control pathways. A recently identified potential cellular target of HPV E7 is the cytoplasmic protein tyrosine phosphatase PTPN14, which is a potential tumor suppressor and is linked to the control of the Hippo and Wnt/beta-catenin signaling pathways. In this study, we show that the E7 proteins of both high-risk and low-risk mucosal HPV types can interact with PTPN14. This interaction is independent of retinoblastoma protein (pRb) and involves residues in the carboxy-terminal region of E7. We also show that high-risk E7 induces proteasome-mediated degradation of PTPN14 in cells derived from cervical tumors. This degradation appears to be independent of cullin-1 or cullin-2 but most likely involves the UBR4/p600 ubiquitin ligase. The degree to which E7 downregulates PTPN14 would suggest that this interaction is important for the viral life cycle and potentially also for the development of malignancy. In support of this we find that overexpression of PTPN14 decreases the ability of HPV-16 E7 to cooperate with activated EJ-ras in primary cell transformation assays. IMPORTANCE This study links HPV E7 to the deregulation of protein tyrosine phosphatase signaling pathways. PTPN14 is classified as a potential tumor suppressor protein, and here we show that it is very susceptible to HPV E7-induced proteasome-mediated degradation. Intriguingly, this appears to use a mechanism that is different from that employed by E7 to target pRb. Therefore, this study has important implications for our understanding of the molecular basis for E7 function and also sheds important light on the potential role of PTPN14 as a tumor suppressor. Copyright © 2017 American Society for Microbiology.

  1. Coal chemistry. 8. Reactions of tetralin with coal and with some carbon-14-containing model compounds

    International Nuclear Information System (INIS)

    Collins, C.J.; Raaen, V.F.; Benjamin, B.M.; Maupin, P.H.; Roark, W.H.

    1979-01-01

    When coal was treated with tetralin-l- 14 C at 400 0 C, small yields of α- and β-methylnaphthalenes- 14 C were observed. In order to determine the mechanism of the reaction, tetralin was heated with 14 C-labeled 1,3-diphenylpropanes (1), with 1,3-diphenylpropene (2), and with 14 C-labeled phenetoles (3). In each case methylnaphthalenes were observed, and the origins of the methyl groups were determined with carbon-14. In addition to the methylnaphthalenes, 1 and 2 also yielded toluene and ethylbenzene (after 19 h), whereas phenetole-β- 14 C (3-β- 14 C) yielded toluene (unlabeled) plus ethyl- 14 C-benzene, benzene, phenol, and a mixture of α- and β-ethyl- 14 C-naphthalenes. Crossover experiments with labeled phenetole and unlabeled ethyl p-tolyl ether proved the intramolecularity of the reaction phenetole → toluene + ethylbenzene, thus illustrating a 1,2-phenyl shift from oxygen to carbon

  2. Rapid localization of carbon 14-labeled molecules in biological samples by ion mass microscopy

    International Nuclear Information System (INIS)

    Hindie, E.; Escaig, F.; Coulomb, B.; Lebreton, C.; Galle, P.

    1989-01-01

    We report here on the ability of secondary ion mass spectrometry (SIMS) to provide rapid imaging of the intracellular distribution of 14 C-labeled molecules. The validity of this method, using mass discrimination of carbon 14 atoms, was assessed by imaging the distribution of two molecules of well-known metabolism, [ 14 C]-thymidine and [ 14 C]-uridine, incorporated by human fibroblasts in culture. As expected, 14 C ion images showed the presence of [ 14 C]-thymidine in the nucleus of dividing cells, whereas [ 14 C]-uridine was present in the cytoplasm as well as the nucleus of all cells, with a large concentration in the nucleoli. The time required to obtain the distribution images with the SMI 300 microscope was less than 6 min, whereas microautoradiography, the classical method for mapping the tissue distribution of 14 C-labeled molecules, usually requires exposure times of several months. Secondary ion mass spectrometry using in situ mass discrimination is proposed here as a very sensitive method which permits rapid imaging of the subcellular distribution of molecules labeled with carbon 14

  3. Investigations into the post-natal development of demethylating enzyme systems by determination of carbon dioxide 14 in the air exhaled by mice after applications of carbon 14 dimethyl amino-antipyrine

    International Nuclear Information System (INIS)

    Schmidt, H.

    1982-01-01

    Albino mice were subcutaneously injected with carbon 14 dimethyl aminopyrines, the methyl group of which can be metabolised in the organism into carbon dioxide 14. The following results were obtained: In the carbon dioxide 14 exhalation of neonate, young and adult animals after administration of carbon 14 aminopyrine, distinct differences were noted. The maximum of elimination via the lungs occurs after 20-30 minutes in grown-up mice, in neonates or young animals distinctly later (60-90 min). The carbon dioxide 14 exhalation was also measured after additional subcutaneous application of methrotrexate. In mice aged 8 and 10 days a distinct decrease in carbon dioxide 14 exhalation was found. By contrast, a rise in carbon dioxide 14 exhaled was found in mice aged 2 days. The orientating experiments with folic acid and carbon 14 dimethyl aminopyrine show that leucovorin leads to a distinct increase in carbon dioxide 14 exhalation during the first 30 minutes. As a cause of the different degrees of stimulation respectively inhibition of demethylation, different biochemical ways of formaldehyde formation are pointed out. One of these probably includes the folate-dependent reaction. (orig./MG) [de

  4. Dissolved Organic Carbon 14C in Southern Nevada Groundwater and Implications for Groundwater Travel Times

    Energy Technology Data Exchange (ETDEWEB)

    Hershey, Ronald L. [Nevada University, Reno, NV (United States). Desert Research Institute; Fereday, Wyall [Nevada University, Reno, NV (United States). Desert Research Institute; Thomas, James M [Nevada University, Reno, NV (United States). Desert Research Institute

    2016-08-01

    Dissolved inorganic carbon (DIC) carbon-14 (14C) ages must be corrected for complex chemical and physical reactions and processes that change the amount of 14C in groundwater as it flows from recharge to downgradient areas. Because of these reactions, DIC 14C can produce unrealistically old ages and long groundwater travel times that may, or may not, agree with travel times estimated by other methods. Dissolved organic carbon (DOC) 14C ages are often younger than DIC 14C ages because there are few chemical reactions or physical processes that change the amount of DOC 14C in groundwater. However, there are several issues that create uncertainty in DOC 14C groundwater ages including limited knowledge of the initial (A0) DOC 14C in groundwater recharge and potential changes in DOC composition as water moves through an aquifer. This study examines these issues by quantifying A0 DOC 14C in recharge areas of southern Nevada groundwater flow systems and by evaluating changes in DOC composition as water flows from recharge areas to downgradient areas. The effect of these processes on DOC 14C groundwater ages is evaluated and DOC and DIC 14C ages are then compared along several southern Nevada groundwater flow paths. Twenty-seven groundwater samples were collected from springs and wells in southern Nevada in upgradient, midgradient, and downgradient locations. DOC 14C for upgradient samples ranged from 96 to 120 percent modern carbon (pmc) with an average of 106 pmc, verifying modern DOC 14C ages in recharge areas, which decreases uncertainty in DOC 14C A0 values, groundwater ages, and travel times. The HPLC spectra of groundwater along a flow path in the Spring Mountains show the same general pattern indicating that the DOC compound composition does not change along this flow path

  5. Land-Based Mitigation Strategies under the Mid-Term Carbon Reduction Targets in Indonesia

    Directory of Open Access Journals (Sweden)

    Tomoko Hasegawa

    2016-12-01

    Full Text Available We investigated the key mitigation options for achieving the mid-term target for carbon emission reduction in Indonesia. A computable general equilibrium model coupled with a land-based mitigation technology model was used to evaluate specific mitigation options within the whole economic framework. The results revealed three primary findings: (1 If no climate policy were implemented, Indonesia’s total greenhouse gas emissions would reach 3.0 GtCO2eq by 2030; (2 To reduce carbon emissions to meet the latest Intended Nationally-Determined Contributions (INDC target, ~58% of total reductions should come from the agriculture, forestry and other land use sectors by implementing forest protection, afforestation and plantation efforts; (3 A higher carbon price in 2020 suggests that meeting the 2020 target would be economically challenging, whereas the INDC target for 2030 would be more economically realistic in Indonesia.

  6. Laboratory Experiments to Evaluate Diffusion of 14C into Nevada Test Site Carbonate Aquifer Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Hershey; William Howcroft; Paul W. Reimus

    2003-03-01

    Determination of groundwater flow velocities at the Nevada Test Site is important since groundwater is the principal transport medium of underground radionuclides. However, 14C-based groundwater velocities in the carbonate aquifers of the Nevada Test Site are several orders of magnitude slower than velocities derived from the Underground Test Area regional numerical model. This discrepancy has been attributed to the loss or retardation of 14C from groundwater into the surrounding aquifer matrix making 14C-based groundwater ages appear much older. Laboratory experiments were used to investigate the retardation of 14C in the carbonate aquifers at the Nevada Test Site. Three sets of experiments were conducted evaluating the diffusion of 14C into the carbonate aquifer matrix, adsorption and/or isotopic exchange onto the pore surfaces of the carbonate matrix, and adsorption and/or isotopic exchange onto the fracture surfaces of the carbonate aquifer. Experimental results a nd published aquifer matrix and fracture porosities from the Lower Carbonate Aquifer were applied to a 14C retardation model. The model produced an extremely wide range of retardation factors because of the wide range of published aquifer matrix and fracture porosities (over three orders of magnitude). Large retardation factors suggest that groundwater with very little measured 14C activity may actually be very young if matrix porosity is large relative to the fracture porosity. Groundwater samples collected from highly fractured aquifers with large effective fracture porosities may have relatively small correction factors, while samples from aquifers with a few widely spaced fractures may have very large correction factors. These retardation factors were then used to calculate groundwater velocities from a proposed flow path at the Nevada Test Site. The upper end of the range of 14C correction factors estimated groundwater velocities that appear to be at least an order of magnitude too high compared

  7. ORIGIN OF PALMITIC ACID CARBON IN PALMITATES FORMED FROM HEXADECANE-1-C14 AND TETRADECANE-1-C14 BY MICROCOCCUS CERIFICANS

    Science.gov (United States)

    Finnerty, W. R.; Kallio, R. E.

    1964-01-01

    Finnerty, W. R. (University of Iowa, Iowa City), and R. E. Kallio. Origin of palmitic acid carbon in palmitates formed from hexadecane-1-C14 and tetradecane-1-C14 by Micrococcus cerificans. J. Bacteriol. 87:1261–1265. 1964.—Degradation of the palmitic acid moiety of cetyl palmitate and myristyl palmitate formed from hexadecane-1-C14 and tetradecane-1-C14 by Micrococcus cerificans was carried out. The patterns of C14 labeling in palmitic acid from cetyl palmitate showed that hexadecane is oxidized at the C1 position, and cetyl alcohol and palmitic acid thus formed are directly esterified. Palmitic acid arising from tetradecane and esterified to tetradecanol appeared to have been synthesized by the addition of two carbon atoms to an existing 14-carbon atom skeleton. Considerable mixing of C14 occurred in the C1 and C2 positions of palmitic acid thus synthesized. PMID:14188700

  8. Synthesis of δ-aminolevulic acid. Application to the introduction of carbon-14 and of tritium

    International Nuclear Information System (INIS)

    Loheac, J.

    1966-06-01

    Several new syntheses of δ aminolevulic acid (δ A.L.A.) have been studied. 14 C-4 δ - aminolevulic acid has been obtained from 14 C allylacetic carboxylic acid with a yield of 30 per cent with respect to barium carbonate and with a specific activity of 32 mCi/mM. The 14 C-1 or 14 C-2 δ-A.L.A. has been prepared from the 14 C-1 or 14 C-2 acetate with a yield of 55 per cent with respect to the acetate. Finally the tritiated δ-A.L.A. has been obtained for the first time by tritiation of ethyl phthalimidodehydrolevulate. (author) [fr

  9. Carbon-14 urea utilization in diagnosis of the presence Campylobacter pylori in stomach

    International Nuclear Information System (INIS)

    Chausson, Y.

    1989-01-01

    A new method to detect the Campylobacter pylori in the stomach, using carbon-14 urea is presented. The technique consists in after the tracer ingestion, the tracer is recuperated by the expiration way in organic hiamin and after counting and evaluating. (M.L.J.)

  10. The leachability of carbon-14-labelled 3,4-benzopyrene from coal ash into aqueous systems

    NARCIS (Netherlands)

    Besemer, A.C.; Kanij, J.

    1984-01-01

    The leachability of polycyclic aromatic hydrocarbons from coal ash into aqueous systems was studied. Carbon-14-labeled 3,4-Benzopyrene (BaP) was deposited on coal fly ash by adsorption from the liquid phase in quantities of about 10 ??g/g ash. After a thermal treatment in air at 120??C for 2 hours

  11. New method of radiation measurement at carbon isotope 14 low level in an environmental atmospheric sampling

    International Nuclear Information System (INIS)

    Tormos, J.

    2009-01-01

    A new method of preparation is proposed to extract the atmospheric carbon trapped in the solution of soda coming from air sampling in environment with a carbon-14 bubbler (type H.A.G. 7000). It is based on the neutralisation of the global soda solution got from bubbling pots by nitric acid, the complete desorption of the carbon under gaseous oxidized form (CO 2 ) and its trapping in a only capacity containing a reactive. The whole of the device is scanned by air at steady rate. A test catch of the reactive and of the trapped carbon dioxide is then blended to a glistening liquid (Permafluor E+) and measured in beta counting by scintillation in liquid medium with a counter for the measurement of low energy beta emitters at very low level of activity (Quantulus type). this method allows to get a limit of detection equal to 5 mBq/m 3 for the atmospheric organic carbon. The principal interest of this method is its quickness and simplicity of setting in motion for a measurement of 14 C in the atmospheric carbon dioxide at a level of natural activity. (N.C.)

  12. Photosynthesis and assimilate partitioning characteristics of the coconut palm as observed by carbon-14 labelling

    International Nuclear Information System (INIS)

    Jayasekara, K.S.; Jayaswkara, K.S.; Bowen, G.D.

    2000-01-01

    A technique was developed on the use of carbon dioxide(carbon-14 labelled) rapid labelling of foliage and to ascertain photosynthesis and partitioning characteristics of labelled assimilate into other parts of the coconut palm. An eight-year-old Tall x Tall young coconut palm growing under field conditions at Bandirippuwa Estate and with six developing bunches , was selected for this study. The labelling was carried out on a bright sunny day and soil was at field capacity. Seventh leaf from the youngest open leaf was used for labelling with 5 mCi of sodium bi carbonate (Carbon-14 labelled). The results revealed that within 24 hours, 60% of the labelled assimilate was partitioned into other parts of the palm and at the end of the seventh day about 18% of the labelled assimilate still remained in the labelled leaf. Among the developing bunches fifth and sixth bunches from the youngest developing bunch received more labelled assimilate than young developing bunches above them. It was revealed that partitioning of assimilate into various ''sinks'' is determined by the developmental stage or activeness of the ''sink''. The proportion of C-14 labelled carbon assimilate, partitioned into developing bunches was substantially low compared to the total amount of labelled carbon fixed by the labelled leaf. Further, it was observed that partitioning of assimilated labelled carbon into the young leaves above, as well as the mature leaves below the labelled leaf. The complex vascular anatomy of the palms could be attributed to this pattern of partitioning of assimilates into upper and lower leaves from the labelled leaf

  13. Carbon-14 kinetic isotope effects and mechanisms of addition of 2,4-dinitrobenzenesulfenyl chloride to substituted styrenes-1-14C and styrenes-2-14C

    International Nuclear Information System (INIS)

    Kanska, M.; Fry, A.

    1983-01-01

    As the first reported examples of carbon isotope effects in simple electrophilic addition reactions we have measured the carbon-14 kinetic isotope effects in the addition of 2,4-dinitrobenzenesulfenyl chloride to a series of para-substituted α and β-labeled styrenes in acetic acid at 30.1 0 C: for para substituents Cl, H, and CH 3 the k/ 14 K values for α labeling are 1.027, 1.022, and 1.004, and the k/ 14 k values for β labeling are 1.035, 1.032, and 1.037, all +/-approx.0.004. The kinetics of the reaction were measured for the p-CH 3 O,p-CH 3 , unsubstituted, p-Cl, and m-NO 2 styrenes; electron-donating groups strongly accelerate the reaction, and electron-withdrawing groups retard it. The Hammett plot is curved with p + values ranging from about -4.6 at the electron-donating group (EDG) end to about -1.8 at the electron-withdrawing group (EWG) end. Both the isotope effect and kinetic data, and related data from the literature, are interpreted in terms of a changing mechanism, with the activated complexes of the rate-determining steps having much open carbenium ion (ion pair) character for EDG-substituted styrenes and much cyclic thiiranium io (ion par) character for EWG-substituted styrenes. 1 figure, 2 tables

  14. Proton induced target fragmentation studies on solid state nuclear track detectors using Carbon radiators

    Science.gov (United States)

    Szabó, J.; Pálfalvi, J. K.; Strádi, A.; Bilski, P.; Swakoń, J.; Stolarczyk, L.

    2018-04-01

    One of the limiting factors of an astronaut's career is the dose received from space radiation. High energy protons, being the main components of the complex radiation field present on a spacecraft, give a significant contribution to the dose. To investigate the behavior of solid state nuclear track detectors (SSNTDs) if they are irradiated by such particles, SSNTD stacks containing carbon blocks were exposed to high energy proton beams (70, 100, 150 and 230 MeV) at the Proteus cyclotron, IFJ PAN -Krakow. The incident protons cannot be detected directly; however, tracks of secondary particles, recoils and fragments of the constituent atoms of the detector material and of the carbon radiator are formed. It was found that as the proton energy increases, the number of tracks induced in the PADC material by secondary particles decreases. From the measured geometrical parameters of the tracks the linear energy transfer (LET) spectrum and the dosimetric quantities were determined, applying appropriate calibration. In the LET spectra the LET range of the most important secondary particles could be identified and their abundance showed differences in the spectra if the detectors were short or long etched. The LET spectra obtained on the SSNTDs irradiated by protons were compared to LET spectra of detectors flown on the International Space Station (ISS): they were quite similar, resulting in a quality factor difference of only 5%. Thermoluminescent detectors (TLDs) were applied in each case to measure the dose from primary protons and other lower LET particles present in space. Comparing and analyzing the results of the TLD and SSNTD measurements, it was obtained that proton induced target fragments contributed to the total absorbed dose in 3.2% and to the dose equivalent in 14.2% in this particular space experiment.

  15. Carbon-14 speciation during anoxic corrosion of activated steel in a repository environment

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, E.; Cvetkovic, B.Z.; Kunz, D. [Paul Scherrer Institute, Villigen (Switzerland). Lab. for Waste Management; Salazar, G.; Szidat, S. [Bern Univ. (Switzerland). Dept. of Chemistry and Biochemistry and Oeschger Centre for Climate Change Research

    2018-01-15

    Radioactive waste contains significant amounts of {sup 14}C which has been identified a key radionuclide in safety assessments. In Switzerland, the {sup 14}C inventory of a cement-based repository for low- and intermediate-level radioactive waste (L/ILW) is mainly associated with activated steel (∝85 %). {sup 14}C is produced by {sup 14}N activation in steel parts exposed to thermal neutron flux in light water reactors. Release of {sup 14}C occurs in the near field of a deep geological repository due to anoxic corrosion of activated steel. Although the {sup 14}C inventory of the L/ILW repository and the sources of {sup 14}C are well known, the formation of {sup 14}C species during steel corrosion is only poorly understood. The aim of the present study was to identify and quantify the {sup 14}C-bearing carbon species formed during the anoxic corrosion of iron and steel and further to determine the {sup 14}C speciation in a corrosion experiment with activated steel. All experiments were conducted in conditions similar to those anticipated in the near field of a cement-based repository.

  16. Study of the potential of low carbon energy development and its contribution to realize the reduction target of carbon intensity in China

    International Nuclear Information System (INIS)

    Li Hongqiang; Wang Limao; Shen Lei; Chen Fengnan

    2012-01-01

    Appraising low carbon energy potential in China and studying its contribution to China's target of cutting CO 2 emissions by 40–45% per unit of GDP by 2020 is crucial for taking countermeasures against climate change and identifying low carbon energy development strategies. This paper presents two scenarios and evaluates the development potential for low carbon energy and its various sources. Based on the evaluation, we analyze how low carbon energy contributes to achieving China's national target of carbon intensity reduction. We draw several conclusions from the analysis. First, low carbon energy will contribute 9.74% (minimum) to 24.42% (maximum) toward the 2020 carbon intensity target under three economic development schemes. Second, the contribution will decrease when the GDP growth rate increases. Third, to maintain the same contribution with high GDP growth rates, China should not only strengthen its investment and policy stimulation for low carbon energy but also simultaneously optimize economic structures and improve carbon productivity. - Highlights: ► Low carbon energy can substitute at least 659.5 Mtce of fossil energy in 2020. ► Potential of hydropower ranks first among all low carbon energy sources in 2020. ► Low carbon energy will contribute at least 9.47% to reach carbon target in 2020. ► China should formulate and implement comprehensive measures to cut carbon emission.

  17. The interaction of carbon-14 carbonate solution species with semiarid sediment

    International Nuclear Information System (INIS)

    Martin, W.J.

    1991-10-01

    14 C is a waste product that has been and may continue to be disposed and/or released into our environment. Subsurface land disposal has been considered as a means of control of nuclear waste and disposal of contaminant migration in the environment. Semiarid environments are preferred for subsurface disposal of solid and liquid wastes. However, such disposal of 14 C may potentially introduce it into the subsurface and groundwater environmental pathways. A limited amount of site-specific data have been published for 14 C transport through the subsurface and groundwater pathways. The experiments conducted in this study perform two functions: (1) they provide a specific impetus for further experimental work and (2) they give credibility to the estimated values used in environmental dose modeling. 11 refs., 1 fig., 1 tab

  18. Spatial targeting of conservation tillage to improve water quality and carbon retention benefits

    International Nuclear Information System (INIS)

    Yang, W.; Sheng, C.; Voroney, P.

    2005-01-01

    Conservation tillage reduces soil erosion and improves water quality in agricultural watersheds. However, the benefits of conservation tillage in carbon sequestration are the subject of controversy. Public funds are provided to farms to encourage the adoption of conservation tillage. Given the economic costs, the targeting of areas likely to achieve the greatest environmental benefits has become an important policy-making issue. A geographic information system (GIS) based modelling framework which integrated hydrologic, soil organic matter, and farm models to evaluate the spatial targeting of conservation tillage was presented. A case study applying the framework in the Fairchild Creek watershed in Ontario indicated that targeting conservation tillage based on sediment abatement goals can achieve comparable carbon retention benefits in terms of the percentage reduction of base carbon losses. Targeted subcatchments for conservation tillage varied across the watershed based on benefit to cost ratios. Conservation tillage patterns based on carbon retention goals showed similar results to sediment abatement goals but slight differences were observed because of different carbon content in the soils. The results indicated that sediment abatement may be used as an indicator in setting up program goals. The impacts of conservation programs can then be evaluated based on calibrated and validated hydrologic models in conjunction with monitoring data. Results also showed that setting carbon retention may lead to higher costs in order to achieve corresponding sediment abatement benefits. Carbon retention may not be suitable for setting as a stand-alone environmental goal for conservation programs because of the difficulties in verifying the impacts and the discrepancies between carbon and sediment benefits. It was concluded that the modelling results have important policy implications for the design of conservation stewardship programs that aim to achieve environmental

  19. A simple model for the trapping of deuterons in a carbon target

    International Nuclear Information System (INIS)

    Erents, S.K.; Hotston, E.S.

    1980-01-01

    A model is proposed for the trapping of deuterons in an annealed carbon target. The deuterons are assumed to be lodged in traps which are created by the ion beam implanting the deuterons. There is a saturation trap density of 6.8 x 10 22 cm -3 . A deuteron in a region of the target where all the traps are filled is free to execute a random walk until it finds a vacant trap or is released from the target surface. The number of ions trapped per unit area of the target surface has been calculated as a function of ion fluence and is in good agreement with the experimental results. (orig.)

  20. Minimizing the non-specific binding of nanoparticles to the brain enables active targeting of Fn14-positive glioblastoma cells.

    Science.gov (United States)

    Schneider, Craig S; Perez, Jimena G; Cheng, Emily; Zhang, Clark; Mastorakos, Panagiotis; Hanes, Justin; Winkles, Jeffrey A; Woodworth, Graeme F; Kim, Anthony J

    2015-02-01

    A major limitation in the treatment of glioblastoma (GBM), the most common and deadly primary brain cancer, is delivery of therapeutics to invading tumor cells outside of the area that is safe for surgical removal. A promising way to target invading GBM cells is via drug-loaded nanoparticles that bind to fibroblast growth factor-inducible 14 (Fn14), thereby potentially improving efficacy and reducing toxicity. However, achieving broad particle distribution and nanoparticle targeting within the brain remains a significant challenge due to the adhesive extracellular matrix (ECM) and clearance mechanisms in the brain. In this work, we developed Fn14 monoclonal antibody-decorated nanoparticles that can efficiently penetrate brain tissue. We show these Fn14-targeted brain tissue penetrating nanoparticles are able to (i) selectively bind to recombinant Fn14 but not brain ECM proteins, (ii) associate with and be internalized by Fn14-positive GBM cells, and (iii) diffuse within brain tissue in a manner similar to non-targeted brain penetrating nanoparticles. In addition, when administered intracranially, Fn14-targeted nanoparticles showed improved tumor cell co-localization in mice bearing human GBM xenografts compared to non-targeted nanoparticles. Minimizing non-specific binding of targeted nanoparticles in the brain may greatly improve the access of particulate delivery systems to remote brain tumor cells and other brain targets. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Hot target assembly at 14 UD Pelletron Accelerator Facility, BARC- TIFR, Mumbai

    International Nuclear Information System (INIS)

    Sharma, S.C.; Ramjilal; Ninawe, N.G.; Bhagwat, P.V.; Ahmeabadhai, P.; Kain, V.

    2005-01-01

    BARC-TIFR 14 UD Pelletron Accelerator Facility at Mumbai is operational since 1989 with progressively increased efficiency. The accelerator has been serving as major facility for heavy ion based research in India. There is an increased demand for high current proton beam, especially on heated targets for reactor physics based experiments. A proton beam setup is commissioned in the tower area of the existing facility itself, which provide proton beam of energy 2 MeV to 26 MeV with maximum 3 μA current. This setup is being used to produce radioisotopes and tracer packets. Proton beam of few MeV in μA current range is also needed to study radiation effects on metals at higher temperature, for use in reactors. For this purpose a hot target assembly has been designed and is being currently used at the Pelletron Accelerator

  2. An integrated approach to geological disposal of UK wastes containing carbon-14

    International Nuclear Information System (INIS)

    Vines, Sarah; Lever, David

    2013-01-01

    Carbon-14 is a key radionuclide in the assessment of the safety of a geological disposal facility for radioactive waste because of the calculated assessment of the radiological consequences of gaseous carbon-14 bearing species [i]. It may be that such calculations are based on overly conservative assumptions and that better understanding could lead to considerably reduced assessment of the radiological consequences from these wastes. Alternatively, it may be possible to mitigate the impact of these wastes through alternative treatment, packaging or design options. The Radioactive Waste Management Directorate of the UK's Nuclear Decommissioning Authority (NDA RWMD) has established an integrated project team in which the partners are working together to develop a holistic approach to carbon-14 management in the disposal system [ii]. For a waste stream containing carbon-14 to be an issue: There must be a significant inventory of carbon-14 in the waste stream; and That waste stream has to generate carbon-14 bearing gas; and a bulk gas phase has to entrain the carbon-14 bearing gas: and these gases must migrate through the engineered barriers in significant quantities; and these gases must migrate through the overlying geological environment (either as a distinct gas phase or as dissolved gas); and these gases must interact with materials in the biosphere (i.e. plants) in a manner that leads to significant doses and risks to exposed groups or potentially exposed groups. The project team has developed and used this 'and' approach to structure and prioritise the technical work and break the problem down in a manageable way. We have also used it to develop our approach to considering alternative treatment, packaging and design options. For example, it may be possible to pre-treat some wastes to remove some of the inventory or to segregate other wastes so that they are removed from any bulk gas phase which might facilitate migration through the geosphere

  3. An integrated approach to geological disposal of UK wastes containing carbon-14

    Energy Technology Data Exchange (ETDEWEB)

    Vines, Sarah [Nuclear Decommissioning Authority, Harwell, Oxfordshire (United Kingdom); Lever, David [AMEC, Harwell, Oxfordshire (United Kingdom)

    2013-07-01

    Carbon-14 is a key radionuclide in the assessment of the safety of a geological disposal facility for radioactive waste because of the calculated assessment of the radiological consequences of gaseous carbon-14 bearing species [i]. It may be that such calculations are based on overly conservative assumptions and that better understanding could lead to considerably reduced assessment of the radiological consequences from these wastes. Alternatively, it may be possible to mitigate the impact of these wastes through alternative treatment, packaging or design options. The Radioactive Waste Management Directorate of the UK's Nuclear Decommissioning Authority (NDA RWMD) has established an integrated project team in which the partners are working together to develop a holistic approach to carbon-14 management in the disposal system [ii]. For a waste stream containing carbon-14 to be an issue: There must be a significant inventory of carbon-14 in the waste stream; and That waste stream has to generate carbon-14 bearing gas; and a bulk gas phase has to entrain the carbon-14 bearing gas: and these gases must migrate through the engineered barriers in significant quantities; and these gases must migrate through the overlying geological environment (either as a distinct gas phase or as dissolved gas); and these gases must interact with materials in the biosphere (i.e. plants) in a manner that leads to significant doses and risks to exposed groups or potentially exposed groups. The project team has developed and used this 'and' approach to structure and prioritise the technical work and break the problem down in a manageable way. We have also used it to develop our approach to considering alternative treatment, packaging and design options. For example, it may be possible to pre-treat some wastes to remove some of the inventory or to segregate other wastes so that they are removed from any bulk gas phase which might facilitate migration through the geosphere

  4. Interaction of 14 MeV neutrons with hydrogenated target proton emission calculation

    International Nuclear Information System (INIS)

    Martin, G.; Perez, N.; Desdin.

    1996-01-01

    Using neutron emission data of a 14 MeV neutron generator, a paraffin target, and based on the n + H 1 → n '+ p reaction, have been obtained the characteristics of the proton emission in a proton-neutron mixed field. It was used Monte Carlo simulation and it was obtained the proton output as function of the converter width and the energy spectrum of protons corresponding to different converter thickness. Among 0.07 and 0.2 cm there is a maximum zone for the proton emission. The energy spectrum agrees with obtained on previous papers. Figures showing these results are provided

  5. Target fragmentation in deep inelastic scattering of 14.5 GeV electrons from nuclei

    International Nuclear Information System (INIS)

    Degtyarenko, P.; Gavrilov, V.; Shuvalov, S.

    1993-01-01

    Results will be presented for inclusive pion, kaon, proton and deuteron electroproduction from light nuclei (mainly 12 C and 16 O) of the residual gas in the beam pipe of the TPC/2γ detector at SLAC. Counter-circulating beams of 14.5 GeV electrons and positrons were used. Comparison will be made with the fragmentation of 2 H, 40 Ar, and Xe target nuclei in several regions of Q 2 and ν. The dependence of the hadron production on the hadron's kinetic energy, emission angle, and x f will be presented. The results will be compared with models of nuclear fragmentation

  6. Physiological conditions and uptake of inorganic carbon-14 by plant roots

    International Nuclear Information System (INIS)

    Amiro, B.D.; Ewing, L.L.

    1992-01-01

    The uptake of inorganic 14 C by bean plant roots was measured. The plants were grown in a nutrient solution culture at pH 6 and a NaH 14 CO 3 tracer was added to the growth medium. Photosynthesis and transpiration were varied by exposing the aerial portions of the plants to different atmospheric CO 2 concentrations, humidities and light levels in a cuvette system. Leaf concentrations of 14 C were measured at the end of the experiments using liquid scintillation counting. Plant uptake of 14 C via the roots was independent of the photosynthetic rate and, in most cases, could be predicted by knowing the transpiration rate and the nutrient solution concentration. However, when a less efficient root-medium aeration system was used, 14 C uptake was greater than that predicted using transpiration, a phenomenon observed by other researchers. This contrasted to results of another experiment where the measured uptake of iodine was much slower than that predicted using transpiration. Knowledge of transpiration rates is useful in predicting inorganic carbon uptake via the roots and in estimating 14 C transport from contaminated soils to biota. Also, the independence of the uptake from photosynthesis and ambient CO 2 concentrations suggests that future increases in atmospheric CO 2 concentrations may not have a direct effect on root uptake of soil carbon. (author)

  7. Effect of fasting and different diets on 14C incorporation from U-14C glucose into glycogen and carbon dioxide by cerebral cortical slices of rats

    International Nuclear Information System (INIS)

    Visweswaran, P.; Binod Kumar; Sinha, A.P.; Suraiya, A.; Brahamchari, A.K.; Singh, S.P.

    1994-01-01

    There are some reports regarding change in the glycogen level due to fasting. Here an attempt is made by keeping the albino rats under fasting or feeding different diets on the rate of 14 C incorporation into glycogen and carbon dioxide from U- 14 C glucose. Our study reveals that the above conditions do not alter any significant change in the glycogen and carbon dioxide in the cerebral cortical slices of albino rats. (author). 8 refs., 1 tab

  8. CO2-laser decomposition method of carbonate for AMS 14C measurements

    International Nuclear Information System (INIS)

    Kitagawa, Hiroyuki

    2013-01-01

    A CO 2 laser decomposition method enabled the efficient preparation of carbonate samples for AMS 14 C measurement. Samples were loaded in a vacuum chamber and thermally decomposed using laser emission. CO 2 liberated from the carbonate was directly trapped in the cold finger trap of a small CO 2 reduction reactor and graphitized by a hydrogen gas reduction method using catalytic iron powder. The fraction modern values for 0.07–0.57 mg of carbon, obtained from 200 μm-diameter spots of IAEA-C1, varied with sample size in the range of 0.00072 ± 0.00003 to 0.00615 ± 0.00052. The contamination induced by the laser decomposition method and the following graphite handling was estimated to be 0.53 ± 0.21 μg of modern carbon, assuming a constant amount of extraneous carbon contamination. This method could also make it possible to avoid the time-consuming procedures of the conventional acid dissolution method that involves multiple complex steps for the preparation of carbonate samples.

  9. Effect of graphite target power density on tribological properties of graphite-like carbon films

    Science.gov (United States)

    Dong, Dan; Jiang, Bailing; Li, Hongtao; Du, Yuzhou; Yang, Chao

    2018-05-01

    In order to improve the tribological performance, a series of graphite-like carbon (GLC) films with different graphite target power densities were prepared by magnetron sputtering. The valence bond and microstructure of films were characterized by AFM, TEM, XPS and Raman spectra. The variation of mechanical and tribological properties with graphite target power density was analyzed. The results showed that with the increase of graphite target power density, the deposition rate and the ratio of sp2 bond increased obviously. The hardness firstly increased and then decreased with the increase of graphite target power density, whilst the friction coefficient and the specific wear rate increased slightly after a decrease with the increasing graphite target power density. The friction coefficient and the specific wear rate were the lowest when the graphite target power density was 23.3 W/cm2.

  10. Sampling and monitoring of carbon-14 in gaseous effluents from nuclear facilities - a literature survey

    International Nuclear Information System (INIS)

    Snellman, M.

    1988-12-01

    C-14 compounds produced in the coolant may be released mainly together with off-gas and waste water from the coolant purification and treatment system. In reactors the release of C-14 will occur mainly in gaseous effluents and only a few percent in liquid effluents. Reported releases from BWRs range from 260 to 670 GBq/GW(e) x year and from 90 to 430 GBq/GW(e) x year for PWRs. At BWRs the condenser air ejector contributes the main inplant release pathway, whereas in PWRs the off-gas treatment vents are the main pathway for C-14 release. C-14 sampling methods depend generally on the C-14 being in the form of CO 2 . The off-gas discharges from BWRs are mainly in the form of CO 2 whereas in PWRs a major fraction of the released C-14 is in the form of hydrocarbons or carbon monoxide (generally 80-100%). Sampling systems in PWRs should therefore be equipped with a catalytic oxidizer to convert all C-14 to CO 2 before trapping. The purpose of this study is to provide information on the techniques available for sampling and monitoring C-14

  11. Algal C-14 and total carbon metabolisms 2. Experimental observations with the diatom Skeletonema costatum

    DEFF Research Database (Denmark)

    Williams, P.J.L.; Robinson, C.; Søndergaard, M.

    1996-01-01

    Three sets of comparisons of net and gross inorganic carbon assimilation and C-14 uptake were made with an axenic culture of Skeletonema costatum. The comparisons showed that in the physiological window studied (10-20% of the intrinsic generation time and gross photosynthesis/respiration ratios...... of 2-3), C-14 uptake into the particulate plus the dissolved fractions approximated to net photosynthesis. Rate constants derived from the chemically determined changes were used to parameterize models that accounted for the respiration of photosynthetic products and for the recycling of respiratory CO......2. The conclusion drawn was that over the time scale studied, the C-14 technique was measuring net photosynthesis, consistent with essentially 100% recycling of respiratory CO2. The study has shown that we now possess the basis to make a rigorous analysis of net, gross CO2 fixation and net C-14...

  12. Requirements for controlling a repository's releases of carbon-14 dioxide; the high costs and negligible benefits

    International Nuclear Information System (INIS)

    Park, U Sun; Pflum, C.G.

    1990-01-01

    A repository excavated within the unsaturated zone may release carbon (C)-14 dioxide in amounts that exceed limits imposed by the Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC). The release would not threaten the general population, but may expose some hypothetical maximally exposed individual to 0.0005 millirems/year. Yet a repository's releases of C-14 dioxide are strictly regulated, perhaps unintentionally. The EPA and NRC regulations could force the Department of Energy to design and fabricate an expensive 10,000-year waste package solely for the sake of controlling releases of C-14 dioxide. This paper argues that the repository regulations should exempt releases of C-14 dioxide or at least impose more equitable limits. 21 refs., 1 tab

  13. Study of the behaviour of organic carbon in the soil, and carbon 14 study of podzols; Contribution a l'etude du comportement du carbone organique dans le sol et etude des podzols a l'aide du carbone 14

    Energy Technology Data Exchange (ETDEWEB)

    Nakhla Shawki, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    Using the penetration into soil of carbon 14 of thermo-nuclear origin, the behaviour and renewal rate were studied on different organic fractions of the soil. It was established that 18% of the total organic matter is renewed in about 400 years. In addition the formation of podzol-type fossil soils in France was dated from the first millenary B.C., i.e. the end of the sub-boreal period and the beginning of the atlantic period. (author) [French] En utilisant la penetration dans le sol du carbone 14 d'origine thermonucleaire, on a etudie le comportement et la vitesse de renouvellement des differentes fractions de la matiere organique du sol. On a pu preciser que 18% de la matiere organique globale se renouvelait en 400 ans environ. Par ailleurs, la formation en France des sols fossiles du type podzol a ete datee du premier millenaire avant J.C. c'est a dire a la fin de la periode subboreale et au debut de la periode atlantique. (auteur)

  14. Carbon-14 in neutron-irradiated graphite for graphite-moderated reactors. Joint research

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Kimio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Matsuo, Hideto [Radioactive Waste Management and Nuclear Facility Decommissioning Technology Center, Tokyo (Japan)

    2002-12-01

    The graphite moderated gas cooled reactor operated by the Japan Atomic Power Company was stopped its commercial operation on March 1998, and the decommissioning process has been started. Graphite material is often used as the moderator and the reflector materials in the core of the gas cooled reactor. During the operation, a long life nuclide of {sup 14}C is generated in the graphite by several transmutation reactions. Separation of {sup 14}C isotope and the development of the separation method have been recognized to be critical issues for the decommissioning of the reactor core. To understand the current methodologies for the carbon isotope separation, literature on the subject was surveyed. Also, those on the physical and chemical behavior of {sup 14}C were surveyed. This is because the larger part of the nuclides in the graphite is produced from {sup 14}N by (n,p) reaction, and the location of them in the material tends to be different from those of the other carbon atoms. This report summarizes the result of survey on the open literature about the behavior of {sup 14}C and the separation methods, including the list of the literature on these subjects. (author)

  15. Synthesis of carbon-14-labeled sodium palmoxirate and its coenzyme A ester

    Energy Technology Data Exchange (ETDEWEB)

    Weaner, L.E.; Hoerr, D.C.

    1986-04-01

    Synthetic procedures for the preparation of carbon-14-labeled sodium palmoxirate (TDGA), labeled either in the carboxyl position or in the tetradecyl hydrocarbon chain, are described. In addition, the synthesis of the coenzyme A ester of TDGA-14C with a specific activity of 51 mCi/mmol is reported. The coenzyme A ester was prepared by formation of the acyl chloride with oxalyl chloride followed by reaction with coenzyme A (CoA) in a borate-buffered tetrahydrofuran solution. Purification methods and analytical and stability data are reported for the compounds.

  16. First accelerator carbon-14 date for pigment from a rock painting

    International Nuclear Information System (INIS)

    Van der Merwe, N.J.; Sealy, J.; Yates, R.

    1987-01-01

    South Africa is particularly blessed with rock art: thousands of paintings and engravings provide a window on the cognitive systems of prehistoric populations. A major stumbling block in studying the art is the lack of a method for dating it. This article shows that some of the paintings can be directly dated by means of accelerator 14 C counting of carbon from black pigment. The advent of accelerator 14 C provides the capability of analysing very small samples and brings pigments from rock paintings into the realm of datable materials

  17. MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

    Energy Technology Data Exchange (ETDEWEB)

    Stephen C. Ruppel

    2005-02-01

    Despite declining production rates, existing reservoirs in the US contain large quantities of remaining oil and gas that constitute a huge target for improved diagnosis and imaging of reservoir properties. The resource target is especially large in carbonate reservoirs, where conventional data and methodologies are normally insufficient to resolve critical scales of reservoir heterogeneity. The objectives of the research described in this report were to develop and test such methodologies for improved imaging, measurement, modeling, and prediction of reservoir properties in carbonate hydrocarbon reservoirs. The focus of the study is the Permian-age Fullerton Clear Fork reservoir of the Permian Basin of West Texas. This reservoir is an especially appropriate choice considering (a) the Permian Basin is the largest oil-bearing basin in the US, and (b) as a play, Clear Fork reservoirs have exhibited the lowest recovery efficiencies of all carbonate reservoirs in the Permian Basin.

  18. Carbon-14 immobilization via the CO2-Ba(OH)2 hydrate gas-solid reaction

    International Nuclear Information System (INIS)

    Haag, G.L.

    1980-01-01

    Although no restrictions have been placed on the release of carbon-14, it has been identified as a potential health hazard due to the ease in which it may be assimilated into the biosphere. The intent of the Carbon-14 Immobilization Program, funded through the Airborne Waste Program Management Office, is to develop and demonstrate a novel process for restricting off-gas releases of carbon-14 from various nuclear facilities. The process utilizes the CO 2 -Ba(OH) 2 hydrate gas-solid reaction to directly remove and immobilize carbon-14. The reaction product, BaCO 3 , possesses both the thermal and chemical stability desired for long-term waste disposal. The process is capable of providing decontamination factors in excess of 1000 and reactant utilization of greater than 99% in the treatment of high volumetric, airlike (330 ppM CO 2 ) gas streams. For the treatment of an air-based off-gas stream, the use of packed beds of Ba(OH) 2 .8H 2 O flakes to remove CO 2 has been demonstrated. However, the operating conditions must be maintained between certain upper and lower limits with respect to the partial pressure of water. If the water vapor pressure in the gas is less than the dissociation vapor pressure of Ba(OH) 2 .8H 2 O, the bed will deactivate. If the vapor pressure is considerably greater, pressure drop problems will increase with increasing humidity as the particles curl and degrade. Results have indicated that when operated in the proper regime, the bulk of the increase in pressure drop results from the conversion of Ba(OH) 2 .8H 2 O to BaCO 3 and not from the hydration of the commercial Ba(OH) 2 .8H 2 O (i.e. Ba(OH) 2 .7.50H 2 O) to Ba(OH) 2 .8H 2 O

  19. The synthesis of tritium, carbon-14 and stable isotope labelled selective estrogen receptor degraders.

    Science.gov (United States)

    Bragg, Ryan A; Bushby, Nick; Ericsson, Cecilia; Kingston, Lee P; Ji, Hailong; Elmore, Charles S

    2016-09-01

    As part of a Medicinal Chemistry program aimed at developing an orally bioavailable selective estrogen receptor degrader, a number of tritium, carbon-14, and stable isotope labelled (E)-3-[4-(2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)phenyl]prop-2-enoic acids were required. This paper discusses 5 synthetic approaches to this compound class. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Effect of IX column maintenance on carbon-14 concentration in moderator systems

    International Nuclear Information System (INIS)

    Gallagher, C.L.; Tripple, A.W.

    2006-01-01

    The radionuclide 14 C is produced in CANDU reactors primarily by the (n,α) reaction with 17 O. Because of high neutron fluxes in the core, the majority of the 14 C (94.5%) is produced in the moderator. In the moderator system, 14 C is present mainly as CO 2 in the cover gas in dynamic equilibrium with dissolved carbonates, bicarbonates and CO 2 in the moderator water. Emissions of 14 C from reactors occur through venting or leakage of the cover gas. By controlling the dissolved carbonates in the moderator water with an ion exchange (IX) purification system, the amount of 14 C in the cover gas is minimized and thus the emissions of 14 C can be reduced. A study was conducted to measure the 14 C concentrations in the moderator system at Gentilly 2 in order to determine the effectiveness of the purification system in removing 14 C. Moderator water samples were obtained from the inlet and outlet of the purification system from 2004 January 14 to July 12, covering the operation of two IX columns (IX-1 and IX-3). The moderator water samples contained high levels of tritium (∼2 TBq·L -1 ). As both tritium and 14 C are β-radiation emitters, direct counting of moderator water for 14 C is impossible as the signal due to tritium dominates over that of other β-emitters. Therefore, a procedure developed by Caron et al. was used in this study, which involved acidifying the sample to release the dissolved 14 CO 2 as gas and collecting the 14 CO 2 in a base (NaOH), which could then be measured by liquid scintillation counting to determine the 14 C concentration. Both of the IX columns started with 14 C removal efficiencies of about 95%. The efficiency began to decrease almost immediately with the IX-1 column dropping to 80% efficiency after ∼1115 hours. This drop in efficiency also led to an increase in the inlet concentration over time. IX-1 column was removed from service after ∼1745 hours with a 14 C removal efficiency of ∼31%. IX-3 column was then placed in service

  1. The use of barytocalcite for carbon 14 immobilization: One-year leaching behavior

    Energy Technology Data Exchange (ETDEWEB)

    Massoni, Nicolas, E-mail: nicolas.massoni@cea.fr; Marcou, Céline; Rosen, Jérémy; Jollivet, Patrick

    2014-11-15

    The spent nuclear fuel reprocessing process is one of the anthropogenic sources of carbon-14, and since this element is highly mobile in the geosphere, its sequestration is necessary. Several phases and industrial solutions to immobilize this radionuclide have been studied, including the barytocalcite phase BaCa(CO{sub 3}){sub 2} at 8.08 wt.% of C, which has many advantages such as its low specific volume of carbon. Recently, different options to synthesize this phase have been reported. Here we report on the aqueous durability of barytocalcite, studied for one year with pure water at 30 °C, in order to complete the behavior studies. Unexpected leaching behavior was encountered: it had been supposed that barytocalcite would only leach slowly, but after 1 year, it was no longer present. It appears that its simple CaCO{sub 3} and BaCO{sub 3} constituents precipitated, though the overall carbon loss was low during the period studied. This research gives a new insight into the behavior of this phase regarding carbon-14 immobilization.

  2. Applications of environmental tritium and carbon-14 in water resources investigation in Taiyuan region China

    International Nuclear Information System (INIS)

    Cai Zuhuang; Shi Huixin

    1988-01-01

    To evaluate the influence of exploiting karst groundwater by 0.5-1 cubic metre per second by Gujiao Coal Mine on the discharge rate of the major Lancun spring, Jinci spring and Xizhang waterworks in the Taiyuan region, Shanxi Province, and to seek new sources of water to make up for this influence, we carried out systematic hydrogeological studies in this region from 1983 to 1986, including measurement of 180 data of tritium, 49 data of carbon-13, 20 data of carbon-14, as well as more than 2,000 chemical data. Isotopic and chemical data were interpreted and used to distinguish the groundwater system, to determine the mixing ratios of various groundwaters, to trace the movement of groundwater both inside each subsystem and from one subsystem to another. Groundwater ages at 13 sites in the studied region were obtained after correction for mixing with young water, correction for dilution by dead carbon, and correction for variation of initial carbon-14 concentration. The velocity of groundwater flow was determined on the basis of groundwater ages. (author). 3 figs, 5 tabs

  3. Measurement of the carbon 14 activity at natural level in air samples

    International Nuclear Information System (INIS)

    Olivier, A.; Tenailleau, L.; Baron, Y.; Maro, D.

    2004-01-01

    The aim of the study was to measure the carbon 14 activity at natural level in air samples using classical methods of radiochemistry and beta counting. Three different methods have been tested in order to minimise the detection limit. In the three methods, the first step consists in trapping the atmospheric carbon 14 into NaOH (1N) using a bubbling chamber. The atmospheric carbon dioxide reacts with NaOH to form Na 2 CO 3 . In the first method the Na 2 CO 3 solution is mixed with a liquid scintillate and is directly analysed by liquid scintillation counting (LSC). The detection limit is approximately 1 Bq/m 3 of air samples. The second method consists in evaporating the carbonate solution and then counting the solid residue with a proportional gas circulation counter. The detection limit obtained is lower than the first method (0.4 Bq/m 3 of air samples). In the third method, Na 2 CO 3 is precipitated into CaCO 3 in presence of CaCl 2 . CaCO 3 is then analysed by LSC. This method appear to be the most appropriate, the detection limit is 0.05 Bq/m 3 of air samples. (author)

  4. Proportion of biogenic carbon in flue gas by carbon-14 measurement

    International Nuclear Information System (INIS)

    Lehtomaeki, J.; Antson, O.; Hongisto, M.; Knuuttila, M.; Roine, J.; Raesaenen, J.; Tormonen, K.; Jungner, H.

    2007-01-01

    The subject of this project is closely related to EU's emissions trading system and to the current and future monitoring needs therein. The determination of fossil part of emissions originated from various fuels by stack measurements or by laboratory analyses could possibly find users also in other fields outside the ETS (e.g. waste incineration). After the market analysis and preliminary measurements carried out in the previous Biocarbon project this project focused on the development of the sampling method for stack measurements and to the validation of isotope measurements. The results obtained for fossil proportion of the fuel by current methods will be compared to those obtained by isotope measurements. The operation of the sampling system was tested in long period tests in plant conditions. Moreover, the sample preparation methods and isotope measurements were validated by measuring the proportions of biogenic and fossil carbon of known traffic fuel mixtures. The developed service concept can also be utilised as a fraud prevention measure related to the expanding international biofuels-trade. (orig.)

  5. Proportion of biogenic carbon in flue gas by carbon-14 measurement - part 2; Biohiili 2

    Energy Technology Data Exchange (ETDEWEB)

    Lehtomaeki, J.; Antson, O.; Hongisto, M. (VTT Technical Research Centre of Finland, Espoo (Finland)) (and others)

    2009-07-01

    The subject of this project is closely related to EU's emissions trading system and to the current and future monitoring needs therein. The determination of fossil part of emissions originated from various fuels by stack measurements or by laboratory analyses could possibly find users also in other fields outside the ETS - Emission Trading Scheme (e.g. waste incineration). After the market analysis and preliminary measurements carried out in the previous Biocarbon project this project focused on the development of the sampling method for stack measurements and to the validation of isotope measurements. The results obtained for fossil proportion of the fuel by current methods will be compared to those obtained by isotope measurements. The operation of the sampling system was tested in long period tests in plant conditions. Moreover, the sample preparation methods and isotope measurements were validated by measuring the proportions of biogenic and fossil carbon of known traffic fuel mixtures. The developed method can also be utilised as a fraud prevention measure related to the expanding international biofuels-trade. (orig.)

  6. Synthesis of puric bases labelled with carbon 14 and nitrogen 15

    International Nuclear Information System (INIS)

    Lamorre, Yves

    1975-01-01

    In this report for graduation in organic chemistry engineering, the author reports the synthesis of adenine 14 C-2 et 14 C-6 by two different chemical ways from two derivatives of imidazole. He has used adenine 14 C-6 to obtain hypoxanthine 14 C-6, and then, by enzymatic processing, uric acid 14 C-6. He reports the study of the production of guanine 14 C-2 by cyclization of silylated derivative of imidazole with the carbon 14 C sulphur. However, a method of complete synthesis of this same compound revealed to be more practical. This complete synthesis way allowed the labelling of guanine in positions 1, 2 and 3 by the 96 per cent isotopic nitrogen. Nitrogen in positions 7 and 9 could have been labelled by the same way from the ethyl cyanoacetate 15 N and from the sodium nitrite 15 N. The study of the mass spectrum of these compounds labelled with nitrogen 15 N allowed most of fragments obtained during this analysis to be identified [fr

  7. Carbon-14 dynamics in rice: an extension of the ORYZA2000 model

    Energy Technology Data Exchange (ETDEWEB)

    Galeriu, D.; Melintescu, A. [' ' Horia Hulubei' ' National Institute for Physics and Nuclear Engineering, Life and Environmental Physics Department, 30 Reactorului St., POB MG-6, Bucharest-Magurele (Romania)

    2014-03-15

    Carbon-14 ({sup 14}C) is a radionuclide of major interest in nuclear power production. The Fukushima accident changed the public attitude on the use of nuclear energy all over the world. In terms of nuclear safety, the need of quality-assured radiological models was emphasized by many international organizations, and for models used by decision-makers (i.e. regulatory environmental models and radiological models), a moderate conservatism, transparency, relative simplicity and user friendliness are required. Because the interaction between crops and the environment is complex and regulated by many feedback mechanisms, however, these requirements are difficult to accomplish. The present study makes a step forward regarding the development of a robust model dealing with food contamination after a short-term accidental emission and considers a single crop species, rice (Oryza sativa), one of the most widely used rice species. Old and more recent experimental data regarding the carbon dynamics in rice plants are reviewed, and a well-established crop growth model, ORYZA2000, is used and adapted in order to assess the dynamics of {sup 14}C in rice after a short-term exposure to {sup 14}CO{sub 2}. Here, the model is used to investigate the role of the genotype, management and weather on the concentration of radiocarbon at harvest. (orig.)

  8. Modelling the Environmental Transfer of Tritium and Carbon-14 to Biota and Man. Report of the Tritium and Carbon-14 Working Group of EMRAS Theme 1

    International Nuclear Information System (INIS)

    2012-01-01

    Hydrogen and carbon are biologically-regulated, essential elements that are highly mobile in the environment and the human body. As isotopes of these elements, tritium and 14 C enter freely into water (in the case of tritium), plants, animals and humans. This complex behaviour means that there are substantial uncertainties in the predictions of models that calculate the transfer of tritium and 14 C through the environment. The EMRAS Tritium/C14 Working Group (WG) was set up to establish the confidence that can be placed in the predictions of such models, to recommend improved modelling approaches, and to encourage experimental work leading to the development of data sets for model testing. The activities of the WG focused on the assessment of models for organically bound tritium (OBT) formation and translocation in plants and animals, the area where model uncertainties are largest. Environmental 14 C models were also addressed because the dynamics of carbon and OBT are similar. The goals of the WG were achieved primarily through nine test scenarios in which model predictions were compared with observations obtained in laboratory or field studies. Seven of the scenarios involved tritium, covering terrestrial and aquatic ecosystems and steady-state and dynamic conditions. The remaining two scenarios concerned 14 C, one addressing steady-state concentrations in plants and the other time-dependent concentrations in animals. The WG also considered one model intercomparison exercise involving the calculation of doses following a hypothetical, short-term release of tritium to the atmosphere in a farming area. Finally, the WG discussed the nature of OBT and proposed a definition to promote common understanding and usage within the international tritium community. The models used by the various participants varied in complexity from simple specific activity approaches to dynamic compartment models and process-oriented models, in which the various transfer processes were

  9. Modelling the Environmental Transfer of Tritium and Carbon-14 to Biota and Man. Report of the Tritium and Carbon-14 Working Group of EMRAS Theme 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-06-15

    Hydrogen and carbon are biologically-regulated, essential elements that are highly mobile in the environment and the human body. As isotopes of these elements, tritium and {sup 14}C enter freely into water (in the case of tritium), plants, animals and humans. This complex behaviour means that there are substantial uncertainties in the predictions of models that calculate the transfer of tritium and {sup 14}C through the environment. The EMRAS Tritium/C14 Working Group (WG) was set up to establish the confidence that can be placed in the predictions of such models, to recommend improved modelling approaches, and to encourage experimental work leading to the development of data sets for model testing. The activities of the WG focused on the assessment of models for organically bound tritium (OBT) formation and translocation in plants and animals, the area where model uncertainties are largest. Environmental {sup 14}C models were also addressed because the dynamics of carbon and OBT are similar. The goals of the WG were achieved primarily through nine test scenarios in which model predictions were compared with observations obtained in laboratory or field studies. Seven of the scenarios involved tritium, covering terrestrial and aquatic ecosystems and steady-state and dynamic conditions. The remaining two scenarios concerned {sup 14}C, one addressing steady-state concentrations in plants and the other time-dependent concentrations in animals. The WG also considered one model intercomparison exercise involving the calculation of doses following a hypothetical, short-term release of tritium to the atmosphere in a farming area. Finally, the WG discussed the nature of OBT and proposed a definition to promote common understanding and usage within the international tritium community. The models used by the various participants varied in complexity from simple specific activity approaches to dynamic compartment models and process-oriented models, in which the various

  10. Carbon-14 tracer study of polyacrylate polymer in a wastewater plant

    International Nuclear Information System (INIS)

    Martin, J.E.; King, L.W.; Hylko, J.M.

    1990-01-01

    A highly absorbent consumer-product, polyacrylate-polymer material tagged with carbon-14 ( 14 C), was dosed to a standard on-site aerobic wastewater treatment plant which contained a settling chamber, an aeration chamber, and an effluent chamber. Operation of the test plant was essentially the same as that of a control plant even under exaggerated conditions. About 97% of the polymer material was retained in solids deposited in the primary and aeration chambers, and effluent releases were minimal. The use of a 14 C tagging procedure proved to be a successful method for studying the behavior of these complex materials. It may be useful to conduct a further study on retained solids to determine whether microbial decomposition of the polymer material occurs while they remain in typical plants. (author)

  11. Reduction of sources of error and simplification of the Carbon-14 urea breath test

    International Nuclear Information System (INIS)

    Bellon, M.S.

    1997-01-01

    Full text: Carbon-14 urea breath testing is established in the diagnosis of H. pylori infection. The aim of this study was to investigate possible further simplification and identification of error sources in the 14 C urea kit extensively used at the Royal Adelaide Hospital. Thirty six patients with validated H. pylon status were tested with breath samples taken at 10,15, and 20 min. Using the single sample value at 15 min, there was no change in the diagnostic category. Reduction or errors in analysis depends on attention to the following details: Stability of absorption solution, (now > 2 months), compatibility of scintillation cocktail/absorption solution. (with particular regard to photoluminescence and chemiluminescence), reduction in chemical quenching (moisture reduction), understanding counting hardware and relevance, and appropriate response to deviation in quality assurance. With this experience, we are confident of the performance and reliability of the RAPID-14 urea breath test kit now available commercially

  12. An assessment of the inventory of Carbon-14 in the oceans

    International Nuclear Information System (INIS)

    Lassey, K.R.; Manning, M.R.; O'Brien, B.J.

    1987-04-01

    The oceanic inventory for natural 14 C is 19.6x10 29 atoms, an estimate similar to those found by other methods. The 14 C produced from nuclear weapons (1972) is 550x10 26 atoms and 52% was in the oceans. From 1972 to 1985 132x10 26 atoms of bomb 14 C were added. The nuclear power industry produces 0.5x10 26 atoms per year (17% of natural production rate). Most estimates by varying methods indicate an exchange time of carbon from atmosphere to ocean of about seven years or about 22 moles m -2 yr -1 for the surface ocean. The oceanic distribution generally has higher concentrations in low to mid latitudes, and low concentrations in the most southern regions, with the deep ocean retaining levels similar to those before nuclear testing

  13. Study on hydrogen transfer in coal liquefaction by tritium and carbon-14 tracers

    International Nuclear Information System (INIS)

    Nitoh, Osamu; Kabe, Toshiaki; Kabe, Yaeko.

    1985-01-01

    For the analysis of mechanism of hydrogenation and cracking of coal, the liquefaction of Taiheiyo coal using tritium labeled gaseous hydrogen and tritium labeled tetralin with small amounts of carbon-14 labeled naphthalene has been studied. Taiheiyo coal(25g) was thermally decomposed in tetralin or naphthalene solvent(75g) at 400--440 0 C under the initial hydrogen pressure of 5.9MPa for 30min with Ni-Mo-Al 2 O 3 catalyst(0--5g). The reaction mixture in an autoclave was separated by filtration, distillation and solvent extraction. Produced gas, oils and the solvent were analyzed by gas chromatography. The tritium and carbon-14 contents of separated reaction products were measured with a liquid scintilation counter to study the hydrogen transfer mechanism. The distribution of reaction products and the amount of hydrogen transfer from gas or solvent to the products were also determined. In hydrogen donor solvent such as tetralin, the coal liquefaction yield was independent from the catalyst, but the catalyst was effective in hydrocracking of preasphaltene and asphaltene. In naphthalene solvent, the coal liquefaction reaction hardly occured in the absence of the catalyst, because hydrogen transfer from both the solvent and gaseous hydrogen was scarce. Tritium distribution in the reaction products showed that complicated hydrogen exchange reactions between gaseous hydrogen, coal liquids and solvent came out by the presence of coal liquids and catalyst. The very small amounts of carbon-14 transferred to the liquefaction products showed that carbon exchange or transfer between solvent and coal did not take place. (author)

  14. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio

    International Nuclear Information System (INIS)

    Keck, B.D.; Ognibene, T.; Vogel, J.S.

    2010-01-01

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of 14 C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of 14 C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the 14 C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with 14 C corresponds to 30 fg equivalents. AMS

  15. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

    Energy Technology Data Exchange (ETDEWEB)

    Keck, B D; Ognibene, T; Vogel, J S

    2010-02-05

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg

  16. Source terms; isolation and radiological consequences of carbon-14 waste in the Swedish SFR repository

    International Nuclear Information System (INIS)

    Hesboel, R.; Puigdomenech, I.; Evans, S.

    1990-01-01

    The source term, isolation capacity, and long-term radiological exposure of 14 C from the Swedish underground repository for low and intermediate level waste (SFR) is assessed. The prospective amount of 14 C in the repository is assumed to be 5 TBq. Spent ion exchange resins will be the dominant source of 14 C. The pore water in the concrete repository is expected to maintain a pH of >10.5 for a period of at least 10 6 y. The cement matrix of the repository will retain most of the 14 CO 3 2- initially present. Bacterial production of CO 2 and CH 4 from degradation of ion-exchange resins and bitumen may contribute to 14 C release to the biosphere. However, CH 4 contributes only to a small extent to the overall carbon loss from freshwater ecosystems. The individual doses to local and regional individuals peaked with 5x10 -3 and regional individuals peaked with 5x10 -3 and 8x10 -4 μSv y -1 respectively at about 2.4x10 4 years. A total leakage of 8.4 GBq of 14 C from the repository will cause a total collective dose commitment of 1.1 manSv or 130 manSv TBq -1 . (authors)

  17. A perspective on tritium versus carbon-14: ensuring optimal label selection in pharmaceutical research and development.

    Science.gov (United States)

    Krauser, Joel A

    2013-01-01

    Tritium ((3) H) and carbon-14 ((14) C) labels applied in pharmaceutical research and development each offer their own distinctive advantages and disadvantages coupled with benefits and risks. The advantages of (3) H have a higher specific activity, shorter half-life that allows more manageable waste remediation, lower material costs, and often more direct synthetic routes. The advantages of (14) C offer certain analytical benefits and less potential for label loss. Although (3) H labels offer several advantages, they might be overlooked as a viable option because of the concerns about its drawbacks. A main drawback often challenged is metabolic liability. These drawbacks, in some cases, might be overstated leading to underutilization of a perfectly viable option. As a consequence, label selection may automatically default to (14) C, which is a more conservative approach. To challenge this '(14) C-by-default' approach, pharmaceutical agents with strategically selected (3) H-labeling positions based on non-labeled metabolism data have been successfully implemented and evaluated for (3) H loss. From in-house results, the long term success of projects clearly would benefit from a thorough, objective, and balanced assessment regarding label selection ((3) H or (14) C). This assessment should be based on available project information and scientific knowledge. Important considerations are project applicability (preclinical and clinical phases), synthetic feasibility, costs, and timelines. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Targeting progesterone metabolism in breast cancer with l-proline derived new 14-azasteroids.

    Science.gov (United States)

    Singh, Jyotsana; Singh, Ritesh; Gupta, Preeti; Rai, Smita; Ganesher, Asha; Badrinarayan, Preethi; Sastry, G Narahari; Konwar, Rituraj; Panda, Gautam

    2017-08-15

    Breast cancer cell proliferation is promoted by a variety of mitogenic signals. Classically estrogen is considered as most predominant mitogenic signal in hormone-dependent breast cancer and progesterone is primarily considered to have protective effect. However, it is suggested that some progesterone metabolite may promote breast cancer and progesterone metabolites like 5α-pregnane and 4-pregnene could serve as regulators of estrogen-responsiveness of breast cancer cells. Here, we estimated the potential of alternate targeting of breast cancer via progesterone signalling. l-Proline derived novel 14-azasteroid compounds were screened against MCF-7 and MDA-MB-231 cell lines using MTT assay. In silico studies, cell cycle, Annexin-V-FITC/PI, JC-1 mitochondrial assay, ROS analysis were performed to analyse the impact of hit compound 3b on breast cancer cells. Further, we analysed the impact of hit 3b on the progesterone, its metabolites and enzymes responsible for the conversion of progesterone and its metabolites using ELISA. Data suggests that compound 3b binds and down regulates of 5α-reductase by specifically inhibiting production of progesterone metabolites that are capable of promoting breast cancer proliferation, epithelial mesenchymal transition and migration. This study establishes the proof of concept and generation of new leads for additional targeting of breast cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Nanobiotechnology meets plant cell biology: Carbon nanotubes as organelle targeting nanocarriers

    KAUST Repository

    Serag, Maged F.; Kaji, Noritada; Habuchi, Satoshi; Bianco, Alberto; Baba, Yoshinobu

    2013-01-01

    For years, nanotechnology has shown great promise in the fields of biomedical and biotechnological sciences and medical research. In this review, we demonstrate its versatility and applicability in plant cell biology studies. Specifically, we discuss the ability of functionalized carbon nanotubes to penetrate the plant cell wall, target specific organelles, probe protein-carrier activity and induce organelle recycling in plant cells. We also, shed light on prospective applications of carbon nanomaterials in cell biology and plant cell transformation. © 2013 The Royal Society of Chemistry.

  20. Synthesis of 1-(4-methylsulfone-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3- triazole and 1-(4-sulfonamide-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3- triazole as novel carbon-14 anticonvulsant

    International Nuclear Information System (INIS)

    Saemian, N.; Shirvani, G.; Matloubi, H.

    2006-01-01

    Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-fluoro-phenyl)-5-[ 14 C]-1,2,3-triazole and 1-(4-sulfonamide-phenyl)-5-(4- fluoro-phenyl)-5-[ 14 C]-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-fluoro-benzonitrile-[cyano- 14 C]. (author)

  1. Biomeasures and mechanistic modeling highlight PK/PD risks for a monoclonal antibody targeting Fn14 in kidney disease.

    Science.gov (United States)

    Chen, Xiaoying; Farrokhi, Vahid; Singh, Pratap; Ocana, Mireia Fernandez; Patel, Jenil; Lin, Lih-Ling; Neubert, Hendrik; Brodfuehrer, Joanne

    2018-01-01

    Discovery of the upregulation of fibroblast growth factor-inducible-14 (Fn14) receptor following tissue injury has prompted investigation into biotherapeutic targeting of the Fn14 receptor for the treatment of conditions such as chronic kidney diseases. In the development of monoclonal antibody (mAb) therapeutics, there is an increasing trend to use biomeasures combined with mechanistic pharmacokinetic/pharmacodynamic (PK/PD) modeling to enable decision making in early discovery. With the aim of guiding preclinical efforts on designing an antibody with optimized properties, we developed a mechanistic site-of-action (SoA) PK/PD model for human application. This model incorporates experimental biomeasures, including concentration of soluble Fn14 (sFn14) in human plasma and membrane Fn14 (mFn14) in human kidney tissue, and turnover rate of human sFn14. Pulse-chase studies using stable isotope-labeled amino acids and mass spectrometry indicated the sFn14 half-life to be approximately 5 hours in healthy volunteers. The biomeasures (concentration, turnover) of sFn14 in plasma reveals a significant hurdle in designing an antibody against Fn14 with desired characteristics. The projected dose (>1 mg/kg/wk for 90% target coverage) derived from the human PK/PD model revealed potential high and frequent dosing requirements under certain conditions. The PK/PD model suggested a unique bell-shaped relationship between target coverage and antibody affinity for anti-Fn14 mAb, which could be applied to direct the antibody engineering towards an optimized affinity. This investigation highlighted potential applications, including assessment of PK/PD risks during early target validation, human dose prediction and drug candidate optimization.

  2. Carbon-14 isotope effects in the addition of 2,4-dinitrobenzenesulfenyl chloride to styrene-1-14C and styrene-2-14C

    International Nuclear Information System (INIS)

    Kanska, M.; Fry, A.

    1982-01-01

    The carbon-isotope effect reported here represents the first step in a general study of the mechanisms of simple electrophilic addition reactions by isotope effect techniques using the successive labeling approach. The addition of 2,4-dinitrobenzenesulfenyl chloride to styrene was chosen as a ''calibration case'' for the cyclic mechanism. The observed isotope effects at /sup α/C and /sup #betta#/C are fully consistent with the cyclic mechanism and probably inconsistent with the open carbenium ion mechanisms. The values of 12 k/ 14 k indicated in this report are averages (and standard deviations) of values for five different fractions of reaction ranging from 20% to 70% with the calculations being made by all four of the Tong and Yankwich equations for each fraction of reaction. Results indicated that there were no trends in the 12 k/ 14 k values as the fraction of reaction varied, and as can be seen by the low standard deviations, there was good agreement among the values calculated by the four equations. These two facts to indicate that the starting materials were of high chemical and radiochemical purity and that the procedures used in the isotope effect experiments were accurate and properly controlled

  3. Synthesis of a polycyclic aromatic hydrocarbon marked with carbon-14: (b, d e f) dibenzo-chrysene {sup 14}C-7,14; Synthese d'un hydrocarbure aromatique polycyclique marque au carbone 14: le dibenzo (b, d e f) chrysene {sup 14}C-7,14

    Energy Technology Data Exchange (ETDEWEB)

    Chatelain, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    (b, d e f) dibenzo-chrysene C-7,14 has been synthesized from radioactive carbon dioxide and the organic magnesium compound derived from 1,5 dibromo naphthalene. The product has been purified by a very precise series of fractionated chromatographs on alumina having a chromatographic activity. This has necessitated the development of a special technique. (author) [French] Le dibenzo (b, d e f) chrysene 14C-7,14 a ete synthetise au depart de gaz carbonique radioactif et de bis-organomagnesien derive du dibromo-1,5 naphtalene. Le produit a ete purifie par une serie de chromatographies fractionnees sur alumine d'activite chromatographique tres precise. Ceci a fait l'objet d'une mise au point de technique. (auteur)

  4. Metabolism of carbon-14 labelled l-tryptophan, l-kynerenine and hydroxy-l-kynerenine in miners with scleroderma

    International Nuclear Information System (INIS)

    Hankes, L.V.; De Bruin, E.; Jansen, C.R.; Voster, L.; Schmaeler, M.

    1977-01-01

    Six South African white miners were studied with the 2-g l-tryptophan load test and tracer doses of L-tryptophan-7a-carbon-14, L-kynurenine-keto-carbon-14 and hydroxy-L-kynerenine-keto-carbon-14. The breath 14 CO 2 and 14 urinary metabolites were measured. When they were compared with a previous study of American women with scleroderma, similar 14 CO 2 and tryptophan metabolite excretion patterns were observed in the data from the miners. The labelled quinolinic acid excretion was more significantly elevated in the South African miners' urine than in the urine of the American women. The data from both studies suggest that some patients with scleroderma have an altered step in the tryptophan metabolic pathway after hydroxy-anthranilic acid. What relationship exists between the induction of pulmonary silicosis and the subsequent development of scleroderma, requires additional human studies

  5. Application of Alkenone 14C-Based chronostratigraphy in carbonate barren sediments on the Peru Margin.

    Science.gov (United States)

    Higginson, M. J.; Altabet, M. A.; Herbert, T. D.

    2003-04-01

    Despite the availability of high-quality sediment cores in key locations, little paleoclimatic information exists for the Peru margin largely because poor carbonate preservation severely restricts the use of traditional carbonate-based proxies for stratigraphy, dating, and paleo-environmental reconstruction. Many sites also include hiatuses produced by the variable influence of undercurrents on sediment accumulation. To overcome these difficulties, we have developed (in collaboration with T. Eglinton, WHOI) a laboratory facility to successfully extract and purify haptophyte-derived alkenones for compound specific 14C AMS dating (modified from OHKOUCHI et al., 2002). This avoids potential problems with dating bulk organic carbon which we assume, even in an upwelling environment as highly productive as the Peru margin, is not a priori solely of marine origin. In a recently collected, mid-Peru Margin core (ODP Leg 201 Site 1228D), comparison of our alkenone 14C dates with bulk sediment organic carbon dates and known stratigraphic markers produces a very well constrained, curvilinear age-depth relationship for at least the last 14 Kyr. A discrete ash layer at Site 1228D with an adjacent alkenone 14C age of 3890 ± 350 yr, is within error identical to the 14C age of a prominent ash layer (3800 ± 50 yr) found west of the large Peruvian El Misti volcano (16^o18'S, 71^o24'W). In summary, these results show that the Peru margin alkenones are autochthonous (i.e. not from an older, distant source) and provide sufficient dating precision to permit, for the first time, high-resolution paleoceanographic studies in this highly important marine province. Based upon this new chronology, synchronous changes in alkenone-derived SST estimates in two of our independently-dated records are the first to record at high-resolution (a) a large LGM-Holocene SST range in the Tropics (up to 7.8 ^oC during brief events in this upwelling location); and (b) sharp coolings (4 ^oC) consistent with

  6. Determination of the carbon content of domestic farm produces to estimate offsite C-14 ingestion dose

    International Nuclear Information System (INIS)

    Jung, Y. G.; Kim, M. J.; Lee, G. B.

    2003-01-01

    The carbon content of grains, leafy and root vegetables, and fruits which the Koreans usually eat were calculated to use in the estimation of offsite C-14 ingestion dose. With the data of food intake per day in the Report on 1998 national health and nutrition survey- dietary intake survey, 5 age-group integrate d intake of the 4 farm produce groups were extracted for food items and the amount. Intake percentage in each food group were taken as food weighing factor for the foods. Carbon content was calculated using protein, fat, and carbohydrate content of the foods, and multiplied by the corresponding food weighing factor to derive the content of the food groups. The calculated carbon content of grains, leafy and root vegetables, and fruits were 39.%, 4.2%, 8.0%, and 5.9% respectively. Grains and fruits were not much different from ODCM for carbon content, but vegetables were higher by 0.7%∼4.5%

  7. Validation test for carbon-14 migration and accumulation in a Canadian shield lake

    International Nuclear Information System (INIS)

    Bird, G.A.

    1996-09-01

    This particular BIOMOVS II Technical Report is concerned with modelling the transfer of C-14 through the aquatic food chain following release to a Canadian shield lake. Model performance has been tested against field data supplied by Atomic Energy of Canada Limited. Carbon-14 was added in 1978 to the epilimnion of a small Canadian Shield lake to investigate primary production and carbon dynamics. Data from this experiment were used within BIOMOVS II to provide a validation test, which involved modelling the fate of the C-14 added to the lake. The nature of the spike and the subsequent monitoring allowed the investigation of both short-term processes relevant to evaluation of the impacts of accidental releases as well as longer-term processes relevant to routine release and to solid waste disposal. Four models participated in the scenario: 1) a simple mass balance model of a lake (AECL, Whiteshell Laboratories, Canada); 2) a relatively complex deterministic dynamic compartment model (QuantiSci Ltd.,UK); 3) a complex deterministic model (Studsvik Model A) and a more complex probabilistic model (Studsvik Model B; Studsvik Eco and Safety AB, Sweden). Endpoints were C-14 concentrations in water, sediment and whitefish over a thirteen year period. Each model produced reasonable predictions when compared to the observed data and when uncertainty is taken into consideration. About 0.2 to 0.4% of the initial C-14 inventory to the lakes remained in the water at the end of the study, because of internal recycling of C-14 from sediments. The simple AECL model did not account for this internal recycling of C-14 and, in this respect, its predictions were not as realistic as those of the QuantiSci and Studsvik models for concentrations in water. However, the AECL model predictions for the C-14 inventory remaining in lake sediment were closest to the observed values. Overall, Studsvik Model B was the most accurate in simulating C-14 concentrations in water and in whitefish, but

  8. Validation test for carbon-14 migration and accumulation in a Canadian shield lake

    Energy Technology Data Exchange (ETDEWEB)

    Bird, G.A. [AECL, Pinawa, MB (Canada). Whiteshell Labs.] [and others

    1996-09-01

    This particular BIOMOVS II Technical Report is concerned with modelling the transfer of C-14 through the aquatic food chain following release to a Canadian shield lake. Model performance has been tested against field data supplied by Atomic Energy of Canada Limited. Carbon-14 was added in 1978 to the epilimnion of a small Canadian Shield lake to investigate primary production and carbon dynamics. Data from this experiment were used within BIOMOVS II to provide a validation test, which involved modelling the fate of the C-14 added to the lake. The nature of the spike and the subsequent monitoring allowed the investigation of both short-term processes relevant to evaluation of the impacts of accidental releases as well as longer-term processes relevant to routine release and to solid waste disposal. Four models participated in the scenario: (1) a simple mass balance model of a lake (AECL, Whiteshell Laboratories, Canada); (2) a relatively complex deterministic dynamic compartment model (QuantiSci Ltd.,UK); (3) a complex deterministic model (Studsvik Model A) and a more complex probabilistic model (Studsvik Model B; Studsvik Eco and Safety AB, Sweden). Endpoints were C-14 concentrations in water, sediment and whitefish over a thirteen year period. Each model produced reasonable predictions when compared to the observed data and when uncertainty is taken into consideration. About 0.2 to 0.4% of the initial C-14 inventory to the lakes remained in the water at the end of the study, because of internal recycling of C-14 from sediments. The simple AECL model did not account for this internal recycling of C-14 and, in this respect, its predictions were not as realistic as those of the QuantiSci and Studsvik models for concentrations in water. However, the AECL model predictions for the C-14 inventory remaining in lake sediment were closest to the observed values. Overall, Studsvik Model B was the most accurate in simulating C-14 concentrations in water and in whitefish, but

  9. Tumor imaging and targeting potential of an Hsp70-derived 14-mer peptide.

    Directory of Open Access Journals (Sweden)

    Mathias Gehrmann

    Full Text Available We have previously used a unique mouse monoclonal antibody cmHsp70.1 to demonstrate the selective presence of a membrane-bound form of Hsp70 (memHsp70 on a variety of leukemia cells and on single cell suspensions derived from solid tumors of different entities, but not on non-transformed cells or cells from corresponding 'healthy' tissue. This antibody can be used to image tumors in vivo and target them for antibody-dependent cellular cytotoxicity. Tumor-specific expression of memHsp70 therefore has the potential to be exploited for theranostic purposes. Given the advantages of peptides as imaging and targeting agents, this study assessed whether a 14-mer tumor penetrating peptide (TPP; TKDNNLLGRFELSG, the sequence of which is derived from the oligomerization domain of Hsp70 which is expressed on the cell surface of tumor cells, can also be used for targeting membrane Hsp70 positive (memHsp70+ tumor cells, in vitro.The specificity of carboxy-fluorescein (CF- labeled TPP (TPP to Hsp70 was proven in an Hsp70 knockout mammary tumor cell system. TPP specifically binds to different memHsp70+ mouse and human tumor cell lines and is rapidly taken up via endosomes. Two to four-fold higher levels of CF-labeled TPP were detected in MCF7 (82% memHsp70+ and MDA-MB-231 (75% memHsp70+ cells compared to T47D cells (29% memHsp70+ that exhibit a lower Hsp70 membrane positivity. After 90 min incubation, TPP co-localized with mitochondrial membranes in memHsp70+ tumors. Although there was no evidence that any given vesicle population was specifically localized, fluorophore-labeled cmHsp70.1 antibody and TPP preferentially accumulated in the proximity of the adherent surface of cultured cells. These findings suggest a potential association between membrane Hsp70 expression and cytoskeletal elements that are involved in adherence, the establishment of intercellular synapses and/or membrane reorganization.This study demonstrates the specific binding and rapid

  10. Radioactivity measurement of barium carbonate [14C] by liquid scintillation counting

    International Nuclear Information System (INIS)

    Kobayashi, Katsutoshi; Hoizumi, Kiyoshi

    1985-03-01

    Two methods of sample preparation for the measurement of specific activity of BaCO 3 [ 14 C] by external standard method in liquid scintillation counting were studied. BaCO 3 [ 14 C] was decomposed by perchloric acid solution and generated CO 2 [ 14 C] was absorbed by ethylene glycol monomethyl ether solution of monoethanolamine as the method 1 or aqueous sodium hydroxide as the method 2. In order to prepare the sample solution of adequate radioactivity concentration, these carbonate solutions by the methods 1 and 2 were diluted with the suitable organic solvent and distilled water respectively. One tenth millilitre of these sample solutions was added into 10 ml of PPO-toluene scintillator containing 0.1 ml of monoethanolamine in a counting vial and homogeneously dissolved with ethyl alcohol. The results of the radioactivity measurement of BaCO 3 [ 14 C] based on the different method agreed within 5 % and the counting rate was found to be stable for as long as 7 deays or more. Both methods of preparation are suitable for the routine measurement because of their simplicity and feasibility. In the case of method 2, the liquid radioactive waste is almost inorganic solution and recovery in the form of BaCO 3 [ 14 C] is easily performed, so that this method is very advantageous from the view point of the radioactive waste treatement. (author)

  11. Experience of an inter-laboratory exercise for the determination of Carbon-14 in biological samples

    International Nuclear Information System (INIS)

    Baburajan, A.; Rajaram, S.; D'Souza, Renita Shiny; Nayak, Rasmi; Karunakara, N.; Ravi, P.M.; Tripathi, R.M.

    2018-01-01

    Carbon-14 is one of the naturally occurring cosmogenic nuclide with long half life of 5730 y and beta energy, E max : 156 keV produced continuously in the outer atmosphere. It is also produced by the anthropogenic activities like nuclear weapon test, nuclear power plant etc. contributing to the atmospheric inventory. The 14 CO 2 gets incorporated with the plant species during photosynthesis and ultimately reaches to man through food chain. It is important to accurately quantify the level of 14 C in different biological matrices for the computation of radiation dose due to ingestion. There are different methods available for the determination of 14 C in biological samples. The oxidation of the dried sample is one of the methods used for liberating the 14 CO 2 and which in turn re-absorbed using Carbo Sorb and subjected to Liquid scintillation analyses with Permaflour scintillator solution. The paper deals with the quality assurance programme initiated by ESL, Tarapur along with ESL, Kalpakkam and CARER, Mangalore University and share the experience of the inter-laboratory comparison exercise

  12. The Edison lamp: O-15 carbon monoxide production in the target

    International Nuclear Information System (INIS)

    Votaw, J.R.; Satter, M.R.; Sunderland, J.J.; Martin, C.C.; Nickles, R.J.

    1986-01-01

    A target has been developed for the on line production of C 15 O in order to maximize the available activity for PET studies. The target features an internal carbon filament which is heated to perform the conversion from 15 O-O 2 to either C 15 O or C 15 O 2 . After the initial success of a bare carbon filament, the experiment was repeated using a platinum plated filament in the hope that the platinum would act as a catalyst allowing the conversion reaction to C 15 O to take place at reduced temperatures. Results indicate that the Pt did not alter the conversion, but did greatly increase the temperature to which the filament could be heated and it also increased the filament lifetime. (author)

  13. Advances in cancer therapy through the use of carbon nanotube-mediated targeted hyperthermia

    Directory of Open Access Journals (Sweden)

    Iancu C

    2011-08-01

    Full Text Available Cornel Iancu, Lucian Mocan3rd Surgery Clinic, Department of Nanomedicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, RomaniaAbstract: Carbon nanotubes (CNTs are emerging versatile tools in nanomedicine applications, particularly in the field of cancer targeting. Due to diverse surface chemistry and unique thermal properties, CNTs can act as strong optical absorbers in near infrared light where biological systems prove to be highly transparent. The process of laser-mediated ablation of cancer cells marked with biofunctionalized CNTs is frequently termed “nanophotothermolysis.” This paper illustrates the potential of engineered CNTs as laser-activated photothermal agents for the selective nanophotothermolysis of cancer cells.Keywords: carbon nanotubes, cancer targeting, functionalization, optical excitation, cancer treatment

  14. Achieving CO2 reductions in Colombia: Effects of carbon taxes and abatement targets

    International Nuclear Information System (INIS)

    Calderón, Silvia; Alvarez, Andrés Camilo; Loboguerrero, Ana María; Arango, Santiago; Calvin, Katherine; Kober, Tom; Daenzer, Kathryn; Fisher-Vanden, Karen

    2016-01-01

    In this paper we investigate CO 2 emission scenarios for Colombia and the effects of implementing carbon taxes and abatement targets on the energy system. By comparing baseline and policy scenario results from two integrated assessment partial equilibrium models TIAM-ECN and GCAM and two general equilibrium models Phoenix and MEG4C, we provide an indication of future developments and dynamics in the Colombian energy system. Currently, the carbon intensity of the energy system in Colombia is low compared to other countries in Latin America. However, this trend may change given the projected rapid growth of the economy and the potential increase in the use of carbon-based technologies. Climate policy in Colombia is under development and has yet to consider economic instruments such as taxes and abatement targets. This paper shows how taxes or abatement targets can achieve significant CO 2 reductions in Colombia. Though abatement may be achieved through different pathways, taxes and targets promote the entry of cleaner energy sources into the market and reduce final energy demand through energy efficiency improvements and other demand-side responses. The electric power sector plays an important role in achieving CO 2 emission reductions in Colombia, through the increase of hydropower, the introduction of wind technologies, and the deployment of biomass, coal and natural gas with CO 2 capture and storage (CCS). Uncertainty over the prevailing mitigation pathway reinforces the importance of climate policy to guide sectors toward low-carbon technologies. This paper also assesses the economy-wide implications of mitigation policies such as potential losses in GDP and consumption. An assessment of the legal, institutional, social and environmental barriers to economy-wide mitigation policies is critical yet beyond the scope of this paper. - Highlights: • Four energy and economy-wide models under carbon mitigation scenarios are compared. • Baseline results show that CO

  15. Application of the dose limitation system to the control of carbon-14 releases from heavy-water-moderated reactors

    International Nuclear Information System (INIS)

    Beninson, D.; Gonzalez, A.J.

    1982-01-01

    Heavy-water-moderated reactors produce substantially more carbon-14 than light-water reactors. Applying the principles of the systems of dose limitation, the paper presents the rationale used for establishing the release limit for effluents containing this nuclide and for the decisions made regarding the effluent treatment in the third nuclear power station in Argentina. Production of carbon-14 in PHWR and the release routes are analysed in the light of the different effluent treatment possibilities. An optimization assessment is presented, taking into account effluent treatment and waste management costs, and the collective effective dose commitment due to the releases. The contribution of present carbon-14 releases to future individual doses is also analysed in the light of an upper bound for the contribution, representing a fraction of the individual dose limits. The paper presents the resulting requirements for the effluent treatment regarding carbon-14 and the corresponding regulatory aspects used in Argentina. (author)

  16. Contribution of deep sourced carbon from hydrocarbon seeps to sedimentary organic carbon: Evidence from Δ14C and δ13C isotopes

    Science.gov (United States)

    Feng, D.; Peckmann, J.; Peng, Y.; Liang, Q.; Roberts, H. H.; Chen, D.

    2017-12-01

    Sulfate-driven anaerobic oxidation of methane (AOM) limits the release of methane from marine sediments and promotes the formation of carbonates close to the seafloor along continental margins. It has been established that hydrocarbon seeps are a source of dissolved inorganic and organic carbon to marine environments. However, questions remain about the contribution of deep sourced carbon from hydrocarbon seeps to the sedimentary organic carbon pool. For a number of hydrocarbon seeps from the South China Sea and the Gulf of Mexico, the portion of modern carbon was determined based on natural radiocarbon abundances (Δ14C) and stable carbon isotope (δ13Corganic carbon) compositions of the non-carbonate fractions extracted from authigenic carbonates. Samples from both areas show a mixing trend between ideal planktonic organic carbon (δ13C = -22‰ VPDB and 90% modern carbon) and the ambient methane. The δ13Corganic carbon values of non-carbonate fractions from three ancient seep deposits (northern Italy, Miocene; western Washington State, USA, Eocene to Oligocene) confirm that the proxy can be used to constrain the record of sulfate-driven AOM through most of Earth history by measuring the δ13C values of organic carbon. This study reveals the potential of using δ13C values of organic carbon to discern seep and non-seep environments. This new approach is particularly promising when authigenic carbonate is not present in ancient sedimentary environments. Acknowledgments: The authors thank BOEM and NOAA for their years' support of the deep-sea dives. Funding was provided by the NSF of China (Grants: 41422602 and 41373085).

  17. Quantitative carbon-14 autoradiography at the cellular level: principles and application for cell kinetic studies. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Doermer, P [Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Muenchen (Germany, F.R.). Inst. fuer Haematologie

    1981-03-01

    Amounts of radio-labelled substances as low as 10/sup -18/ moles incorporated into individual cells can be measured by utilizing techniques of quantitative autoradiography. The principles and application of quantitative carbon-14 autoradiography are reviewed. Silver grain densities can be counted by automated microphotometry allowing on-line data processing by an interfaced computer. Rate measurements of /sup 14/C-thymidine incorporation into individual cells yield values of the DNA synthesis rate and the DNA synthesis time of a cell compartment can be derived. This is an essential time parameter for the evaluation of kinetic events in proliferating cell populations. This method is applicable to human cells without radiation hazard to man and provides an optimal source of detailed information on the kinetics of normal and diseased human haematopoiesis. Examples of application consist of thalassaemia, malaria infection, iron deficiency anaemia and acute myelogenous leukaemia.

  18. The evolution of carbon-14 and tritium containing gases in a radioactive waste repository

    International Nuclear Information System (INIS)

    Jefferies, N.L.

    1990-04-01

    The principal processes which well lead to the formation of gases in a repository containing low- and intermediate-level radioactive waste have been identified as corrosion, microbiological activity and radiolysis. The largest contribution to gas production is from hydrogen, generated from anaerobic corrosion of metallic components of the waste. Substitution of the active isotopes carbon-14 and hydrogen-3 (tritium) into the bulk gases, H 2 CO 2 and CH 4 may result in a radiological hazard to man. The purpose of this paper is to assess the mechanisms by which C-14 and tritium in solid low- and intermediate-level wastes are partitioned into gases reduced by corrosion and microbial processes. (author)

  19. Carbon-14 based determination of the biogenic fraction of industrial CO(2) emissions - application and validation.

    Science.gov (United States)

    Palstra, S W L; Meijer, H A J

    2010-05-01

    The (14)C method is a very reliable and sensitive method for industrial plants, emission authorities and emission inventories to verify data estimations of biogenic fractions of CO(2) emissions. The applicability of the method is shown for flue gas CO(2) samples that have been sampled in 1-h intervals at a coal- and wood-fired power plant and a waste incineration plant. Biogenic flue gas CO(2) fractions of 5-10% and 48-50% have been measured at the power plant and the waste incineration plant, respectively. The reliability of the method has been proven by comparison of the power plant results with those based on carbon mass input and output data of the power plant. At industrial plants with relatively low biogenic CO(2) fraction (<10%) the results need to be corrected for sampled (14)CO(2) from atmospheric air. Copyright 2009 Elsevier Ltd. All rights reserved.

  20. Quantitative carbon-14 autoradiography at the cellular level: principles and application for cell kinetic studies

    International Nuclear Information System (INIS)

    Doermer, P.

    1981-01-01

    Amounts of radio-labelled substances as low as 10 -18 moles incorporated into individual cells can be measured by utilizing techniques of quantitative autoradiography. The principles and application of quantitative carbon-14 autoradiography are reviewed. Silver grain densities can be counted by automated microphotometry allowing on-line data processing by an interfaced computer. Rate measurements of 14 C-thymidine incorporation into individual cells yield values of the DNA synthesis rate and the DNA synthesis time of a cell compartment can be derived. This is an essential time parameter for the evaluation of kinetic events in proliferating cell populations. This method is applicable to human cells without radiation hazard to man and provides an optimal source of detailed information on the kinetics of normal and diseased human haematopoiesis. Examples of application consist of thalassaemia, malaria infection, iron deficiency anaemia and acute myelogenous leukaemia. (author)

  1. Carbon-14 radiolabelling and tissue distribution evaluation of a potential anti-TB compound.

    Science.gov (United States)

    Sonopo, Molahlehi S; Venter, Kobus; Winks, Susan; Marjanovic-Painter, Biljana; Morgans, Garreth L; Zeevaart, Jan R

    2016-06-15

    This paper describes a five-step synthesis of a carbon-14-labelled pyrazole compound (11). A total of 2.96 MBq of 11 was obtained with the specific activity of 2242.4 MBq/mmol. The radiochemical purity was >99%, and the overall radiochemical yield was 60% based on the [(14) C6 ] 4-bromoaniline starting material. Biodistribution results showed that the radiotracer (administrated orally) has a high accumulation in the small intestine, large intestine and liver of both non-infected and tuberculosis (TB)-infected mice. Therefore, this suggests that compound 11 undergoes hepatobiliary clearance. The compound under investigation has been found to be slowly released from the liver between 2 and 8 h. The study revealed that 11 has no affinity for TB cells. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Biogenesis of tritiated and carbon-14 methane from low-level radioactive waste

    International Nuclear Information System (INIS)

    Francis, A.J.; Dobbs, S.; Doering, R.F.

    1980-01-01

    Methane bacteria were detected in leachate samples collected from commercial low-level radioactive waste disposal sites. Significant amounts of tritiated and carbon-14 methane were generated by a mixed methanogenic culture from a leachate sample collected from the low-level radioactive waste disposal site, Maxey Flats, KY. Tritiated methane was produced by methane bacteria from synthetic media containing 2 mCi of tritium as tritiated water or tritiated acetate, and the level of tritium added to the medium had no effect on methanogenesis. Under anaerobic conditions the organic compounds containing 14 C and 3 H activity and tritiated water in the waste are metabolized by microorganisms and they produce radioactive gases which escape into the environment from the disposal sites. 4 figures, 3 tables

  3. Tritium- and carbon-14-contents of wines of different vintage from the northern and southern hemisphere

    International Nuclear Information System (INIS)

    Fischer, E.; Mueller, H.

    1980-01-01

    The carbon-14 and tritium radioactivity contents of up to 19 vintages of German and Southafrican wines were compared. A similar large dependence of the 14 C- and of the 3 H-activity in the German wine on the nuclear weapon tests of the years 1962/63 was found out. The radioactivity level is also 1977/78 still essentially higher than before 1950. The Southafrican wines have been influenced considerably less by nuclear explosions. The highest 3 H-values were found in the vintage 1963 of the German wine with 5910 pCi/litre and in the vintage 1964 of the Southafrican wine with 510 pCi/litre. (orig.) [de

  4. The application of carbon nanotubes in target drug delivery systems for cancer therapies

    Science.gov (United States)

    Zhang, Wuxu; Zhang, Zhenzhong; Zhang, Yingge

    2011-10-01

    Among all cancer treatment options, chemotherapy continues to play a major role in killing free cancer cells and removing undetectable tumor micro-focuses. Although chemotherapies are successful in some cases, systemic toxicity may develop at the same time due to lack of selectivity of the drugs for cancer tissues and cells, which often leads to the failure of chemotherapies. Obviously, the therapeutic effects will be revolutionarily improved if human can deliver the anticancer drugs with high selectivity to cancer cells or cancer tissues. This selective delivery of the drugs has been called target treatment. To realize target treatment, the first step of the strategies is to build up effective target drug delivery systems. Generally speaking, such a system is often made up of the carriers and drugs, of which the carriers play the roles of target delivery. An ideal carrier for target drug delivery systems should have three pre-requisites for their functions: (1) they themselves have target effects; (2) they have sufficiently strong adsorptive effects for anticancer drugs to ensure they can transport the drugs to the effect-relevant sites; and (3) they can release the drugs from them in the effect-relevant sites, and only in this way can the treatment effects develop. The transporting capabilities of carbon nanotubes combined with appropriate surface modifications and their unique physicochemical properties show great promise to meet the three pre-requisites. Here, we review the progress in the study on the application of carbon nanotubes as target carriers in drug delivery systems for cancer therapies.

  5. MARS14 deep-penetration calculation for the ISIS target station shielding

    International Nuclear Information System (INIS)

    Nakao, Noriaki; Nunomiya, Tomoya; Iwase, Hiroshi; Nakamura, Takashi

    2004-01-01

    The calculation of neutron penetration through a thick shield was performed with a three-dimensional multi-layer technique using the MARS14(02) Monte Carlo code to compare with the experimental shielding data in 1998 at the ISIS spallation neutron source facility of Rutherford Appleton Laboratory. In this calculation, secondary particles from a tantalum target bombarded by 800-MeV protons were transmitted through a bulk shield of approximately 3-m-thick iron and 1-m-thick concrete. To accomplish this deep-penetration calculation, a three-dimensional multi-layer technique and energy cut-off method were used considering a spatial statistical balance. Finally, the energy spectra of neutrons behind the very thick shield could be calculated down to the thermal energy with good statistics, and the calculated results typically agree well within a factor of two with the experimental data over a broad energy range. The 12 C(n,2n) 11 C reaction rates behind the bulk shield were also calculated, which agree with the experimental data typically within 60%. These results are quite impressive in calculation accuracy for deep-penetration problem

  6. Use of the small gas proportional counters for the carbon-14 measurement of very small samples

    International Nuclear Information System (INIS)

    Sayre, E.V.; Harbottle, G.; Stoenner, R.W.; Otlet, R.L.; Evans, G.V.

    1981-01-01

    Two recent developments are: the first is the mass-spectrometric separation of 14 C and 12 C ions, followed by counting of the 14 C, while the second is the extension of conventional proportional counter operation, using CO 2 as counting gas, to very small counters and samples. Although the second method is slow (months of counting time are required for 10 mg of carbon) it does not require operator intervention and many samples may be counted simultaneously. Also, it costs only a fraction of the capital expense of an accelerator installation. The development, construction and operation of suitable small counters are described, and results of three actual dating studies involving milligram scale carbon samples will be given. None of these could have been carried out if conventional, gram-sized samples had been needed. New installations, based on the use of these counters, are under construction or in the planning stages. These are located at Brookhaven Laboratory, the National Bureau of Standards (USA) and Harwell (UK). The Harwell installation, which is in advanced stages of construction, will be described in outline. The main significance of the small-counter method is, that although it will not suffice to measure the smallest (much less than 10 mg) or oldest samples, it will permit existing radiocarbon laboratories to extend their capability considerably, in the direction of smaller samples, at modest expense

  7. Mountain scale modeling of transient, coupled gas flow, heat transfer and carbon-14 migration

    International Nuclear Information System (INIS)

    Lu, Ning; Ross, B.

    1993-01-01

    We simulate mountain-scale coupled heat transfer and gas flow at Yucca Mountain. A coupled rock-gas flow and heat transfer model, TGIF2, is used to simulate mountain-scale two-dimensional transient heat transfer and gas flow. The model is first verified against an analytical solution for the problem of an infinite horizontal layer of fluid heated from below. Our numerical results match very well with the analytical solution. Then, we obtain transient temperature and gas flow distributions inside the mountain. These distributions are used by a transient semianalytical particle tracker to obtain carbon-14 travel times for particles starting at different locations within the repository. Assuming that the repository is filled with 30-year-old waste at an initial areal power density of 57 kw/acre, we find that repository temperatures remain above 60 degrees C for more than 10,000 years. Carbon-14 travel times to the surface are mostly less than 1000 years, for particles starting at any time within the first 10,000 years

  8. PEGylated anticancer-carbon nanotubes complex targeting mitochondria of lung cancer cells

    Science.gov (United States)

    Kim, Sang-Woo; Lee, Yeon Kyung; Lee, Jong Yeon; Hong, Jeong Hee; Khang, Dongwoo

    2017-11-01

    Although activating apoptosis in cancer cells by targeting the mitochondria is an effective strategy for cancer therapy, insufficient targeting of the mitochondria in cancer cells restricts the availability in clinical treatment. Here, we report on a polyethylene glycol-coated carbon nanotube (CNT)-ABT737 nanodrug that improves the mitochondrial targeting of lung cancer cells. The polyethylene glycol-coated CNT-ABT737 nanodrug internalized into the early endosomes via macropinocytosis and clathrin-mediated endocytosis in advance of early endosomal escape and delivered into the mitochondria. Cytosol release of the nanodrug led to apoptosis of lung cancer cells by abruption of the mitochondrial membrane potential, inducing Bcl-2-mediated apoptosis and generating intracellular reactive oxygen species. As such, this study provides an effective strategy for increasing the anti-lung cancer efficacy by increasing mitochondria accumulation rate of cytosol released anticancer nanodrugs.

  9. Synthesis of {delta}-aminolevulic acid. Application to the introduction of carbon-14 and of tritium; Syntheses de l'acide {delta} aminolevulique. Application a l'introduction de carbone 14 et de tritium

    Energy Technology Data Exchange (ETDEWEB)

    Loheac, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-06-01

    Several new syntheses of {delta} aminolevulic acid ({delta} A.L.A.) have been studied. {sup 14}C-4 {delta} - aminolevulic acid has been obtained from {sup 14}C allylacetic carboxylic acid with a yield of 30 per cent with respect to barium carbonate and with a specific activity of 32 mCi/mM. The {sup 14}C-1 or {sup 14}C-2 {delta}-A.L.A. has been prepared from the {sup 14}C-1 or {sup 14}C-2 acetate with a yield of 55 per cent with respect to the acetate. Finally the tritiated {delta}-A.L.A. has been obtained for the first time by tritiation of ethyl phthalimidodehydrolevulate. (author) [French] Plusieurs syntheses nouvelles de l'acide {delta}-aminolevulique ont ete etudiees. L'acide {delta}-aminolevulique {sup 14}C-4 a ete obtenu a partir d'acide allylacetique carboxylique {sup 14}C, avec un rendement global de 30 pour cent par rapport au carbonate de baryum a une activite specifique de 32 mCi/M. Le {delta}-A.A.L. {sup 14}C-1 ou {sup 14}C-2 a ete obtenu a partir d'acetate {sup 14}C-1 ou {sup 14}C-2 avec un rendement de 55 pour cent par rapport a l'acetate. Enfin le {delta}-A.A.L. tritie a ete obtenu pour la premiere fois par tritiation du phtalimidodehydrolevulate d'ethyle. (auteur)

  10. Carbon emission reduction targeting through process integration and fuel switching with mathematical modeling

    International Nuclear Information System (INIS)

    Tiew, B.J.; Shuhaimi, M.; Hashim, H.

    2012-01-01

    Highlights: ► CO 2 emissions reduction targeting for existing plant were categorized into three groups. ► Model for CO 2 emissions reduction targeting via combination approach was developed. ► Effect of combination approach onto HEN area efficiency was discussed. ► Proposed execution strategy can avoid HEN area efficiency deterioration. -- Abstract: Carbon emission reduction targeting is an important and effective effort for industry to contribute in controlling greenhouse gases concentration in atmosphere. Graphical approach has been proposed for CO 2 emissions reduction targeting via HEN retrofit and fuel switching. However, it involves potentially time consuming manual procedures and the quality of solutions produced greatly depends on designer’s experience and judgment. Besides, graphical approach hardly account for the cost factor during the design phase, thus potentially generate complex design. This paper introduces an MINLP model for simultaneous CO 2 emissions reduction targeting via fuel switching and HEN retrofit. A sequential model execution was proposed along with the proposed model. The application of the model on a crude preheat train case study has demonstrated its workability to generate optimal solution for targeted CO 2 emissions reduction at minimum payback period.

  11. Kinetics of extracellular release of 14C-labelled organic carbon by submerged macrophytes

    International Nuclear Information System (INIS)

    Soendergaard, M.

    1981-01-01

    The release of extracellular organic carbon (EOC) by six submerged freswater macrophytes was measured in time course studies with a 14 C-technique. Incubation in light in an open water-flow system made it possible to assay the time courses of 14 C-fixation and the simultaneous release of labelled EOC. Heterotrophic utilization of the released products by epiphytic communities was measured. Two patterns of release kinetics were found: (1) Constant rates of release occurred during the incubations, (2) The rates still increased after 24 h of incubation. During the first hours of incubation the rates of release increased in all species. Elodea reached constant rates after 2-4 h and Littorella and Ceratophyllum demersum after about 20 h. In the experiments with C. submersum and Nitella the rates of release increased almost linearly during the entire incubation period. The kinetics of release were in agreement with the molecular weight distribution of the dissolved EOC measured with gel chromatography. Low molecular weight products ( 10000 Daltons) dominated the dissolved EOC released by C. submersum and Nitella. A large fraction (18-60%) of the total EOC could be recovered on filters with a pore size of 0.2 μm. This particulate fraction probably represents some abiotic removal. The quantities of relase were low in all species and did not exceed 0.9% of the photosynthetic carbon fixation. Heterotrophic uptake by the epiphytic communities was less than 10% of the EOC released. The results emphasize that the 14 C-labelling of extracellular products is a time dependent process. (author)

  12. Revision of Fontes & Garnier's model for the initial 14C content of dissolved inorganic carbon used in groundwater dating

    Science.gov (United States)

    Han, Liang-Feng; Plummer, Niel

    2013-01-01

    The widely applied model for groundwater dating using 14C proposed by Fontes and Garnier (F&G) (Fontes and Garnier, 1979) estimates the initial 14C content in waters from carbonate-rock aquifers affected by isotopic exchange. Usually, the model of F&G is applied in one of two ways: (1) using a single 13C fractionation factor of gaseous CO2 with respect to a solid carbonate mineral, εg/s, regardless of whether the carbon isotopic exchange is controlled by soil CO2 in the unsaturated zone, or by solid carbonate mineral in the saturated zone; or (2) using different fractionation factors if the exchange process is dominated by soil CO2 gas as opposed to solid carbonate mineral (typically calcite). An analysis of the F&G model shows an inadequate conceptualization, resulting in underestimation of the initial 14C values (14C0) for groundwater systems that have undergone isotopic exchange. The degree to which the 14C0 is underestimated increases with the extent of isotopic exchange. Examples show that in extreme cases, the error in calculated adjusted initial 14C values can be more than 20% modern carbon (pmc). A model is derived that revises the mass balance method of F&G by using a modified model conceptualization. The derivation yields a “global” model both for carbon isotopic exchange dominated by gaseous CO2 in the unsaturated zone, and for carbon isotopic exchange dominated by solid carbonate mineral in the saturated zone. However, the revised model requires different parameters for exchange dominated by gaseous CO2 as opposed to exchange dominated by solid carbonate minerals. The revised model for exchange dominated by gaseous CO2 is shown to be identical to the model of Mook (Mook, 1976). For groundwater systems where exchange occurs both in the unsaturated zone and saturated zone, the revised model can still be used; however, 14C0 will be slightly underestimated. Finally, in carbonate systems undergoing complex geochemical reactions, such as oxidation of

  13. A study of the carbon dynamics of Japanese grassland and forest using 14C and 13C

    International Nuclear Information System (INIS)

    Katsuno, Kazumi; Miyairi, Yosuke; Tamura, Kenji; Matsuzaki, Hiroyuki; Fukuda, Kenji

    2010-01-01

    We quantified the carbon contents of grassland and forest soil using conventional methods and studied the changes in their dynamics by measuring δ 13 C and Δ 14 C. Soil samples were taken from a neighboring Miscanthus sinensis grassland and Pinus densiflora forest in central Japan. Both had been maintained as grassland until the 1960s, when the latter was abandoned and became a pine forest by natural succession. The soil carbon content of the forest was much lower than that of the grassland, implying that the soil carbon decreased as the grassland became forest. The δ 13 C values were very similar in the grassland and forest, at approximately -20 per mille , suggesting that M. sinensis (a C4 plant) contributed to carbon storage, whereas there was little carbon accumulation from P. densiflora (a C3 plant) in forest soil. The Δ 14 C values and calculated soil carbon mean residence time (MRT) showed that the soil carbon in the upper A horizon was older, and that in the lower A horizon was younger in forest than in grassland. From these results, we conclude that young, fast-MRT soil carbon is decomposed in the upper A horizon, and old, stable soil carbon was decomposed in the lower A horizon after the pine invasion.

  14. Uncertainties in key low carbon power generation technologies - Implication for UK decarbonisation targets

    International Nuclear Information System (INIS)

    Kannan, R.

    2009-01-01

    The UK government's economy-wide 60% carbon dioxide reduction target by 2050 requires a paradigm shift in the whole energy system. Numerous analytical studies have concluded that the power sector is a critical contributor to a low carbon energy system, and electricity generation has dominated the policy discussion on UK decarbonisation scenarios. However, range of technical, social and market challenges, combined with alternate market investment strategies mean that large scale deployment of key classes of low carbon electricity technologies is fraught with uncertainty. The UK MARKAL energy systems model has been used to investigate these long-term uncertainties in key electricity generation options. A range of power sector specific parametric sensitivities have been performed under a 'what-if' framework to provide a systematic exploration of least-cost energy system configurations under a broad, integrated set of input assumptions. In this paper results of six sensitivities, via restricted investments in key low carbon technologies to reflect their technical and political uncertainties, and an alternate investment strategies from perceived risk and other barriers, have been presented. (author)

  15. Ultra-hard AlMgB14 coatings fabricated by RF magnetron sputtering from a stoichiometric target

    Science.gov (United States)

    Grishin, A. M.; Khartsev, S. I.; Böhlmark, J.; Ahlgren, M.

    2015-01-01

    For the first time hard aluminum magnesium boride films were fabricated by RF magnetron sputtering from a single stoichiometric ceramic AlMgB14 target. Optimized processing conditions (substrate temperature, target sputtering power and target-to-substrate distance) enable fabrication of stoichiometric in-depth compositionally homogeneous films with the peak values of nanohardness 88 GPa and Young's modulus 517 GPa at the penetration depth of 26 nm and, respectively, 35 and 275 GPa at 200 nm depth in 2 μm thick film.

  16. High temperature vacuum furnace for the preparation of graphite targets for 14C dating by tandem accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Lowe, D.C.; Bristow, P.; Judd, W.J.

    1985-02-01

    A simple and reliable furnace design capable of producing temperatures of up to 2800 deg. C is presented. The furnace has been specifically designed for the rapid and reliable production of graphite targets for 14 C dating purposes but may be used in a variety of applications requiring high temperatures under vacuum conditions

  17. An abundance of rare functional variants in 202 drug target genes sequenced in 14.002 people

    DEFF Research Database (Denmark)

    Nelson, Matthew R.; Wegmann, Daniel; Ehm, Margaret G.

    2012-01-01

    Rare genetic variants contribute to complex disease risk; however, the abundance of rare variants in human populations remains unknown. We explored this spectrum of variation by sequencing 202 genes encoding drug targets in 14,002 individuals. We find rare variants are abundant (1 every 17 bases)...

  18. High-Resolution Genetics Identifies the Lipid Transfer Protein Sec14p as Target for Antifungal Ergolines.

    Directory of Open Access Journals (Sweden)

    Ireos Filipuzzi

    2016-11-01

    Full Text Available Invasive infections by fungal pathogens cause more deaths than malaria worldwide. We found the ergoline compound NGx04 in an antifungal screen, with selectivity over mammalian cells. High-resolution chemogenomics identified the lipid transfer protein Sec14p as the target of NGx04 and compound-resistant mutations in Sec14p define compound-target interactions in the substrate binding pocket of the protein. Beyond its essential lipid transfer function in a variety of pathogenic fungi, Sec14p is also involved in secretion of virulence determinants essential for the pathogenicity of fungi such as Cryptococcus neoformans, making Sec14p an attractive antifungal target. Consistent with this dual function, we demonstrate that NGx04 inhibits the growth of two clinical isolates of C. neoformans and that NGx04-related compounds have equal and even higher potency against C. neoformans. Furthermore NGx04 analogues showed fungicidal activity against a fluconazole resistant C. neoformans strain. In summary, we present genetic evidence that NGx04 inhibits fungal Sec14p and initial data supporting NGx04 as a novel antifungal starting point.

  19. Hofmann elimination of p-nitrophenylethyl-1-C-14-trimethylammonium bromide: a carbon-14 isotope effect study (Preprint no. AR-24)

    International Nuclear Information System (INIS)

    Ramamurthy, T.V.; Fry, Arthur

    1991-01-01

    The alpha carbon isotope effects in the Hofmann elimination of p-nitrophenylethyl-1-C-14-trimethylammonium bromide compound have been measured under changing buffer concentrations with a view to correlate mechanistic change. Since there are alpha-carbon isotope effects and the effects are small it is quite likely that the reaction is of the ElcB type, predominately irreversible, with the incursion of slightly increasing fractions of reaction by the reversible mechanism as the buffer concentration is increased. (author). 4 refs., 2 tab

  20. Seasonal dynamics of permafrost carbon emissions: A passive, quasi-continuous 14CO2 sampler

    Science.gov (United States)

    Pedron, S.; Xu, X.; Walker, J. C.; Welker, J. M.; Klein, E. S.; Euskirchen, E. S.; Czimczik, C. I.

    2017-12-01

    Millennia of carbon (C) fixation by tundra vegetation, coupled with low rates of C mineralization by soil microorganisms and preservation in permafrost, have allowed Arctic soils to accumulate vast quantities of organic C (1672 Pg C total). Today, the Arctic is rapidly warming (0.48oC decade-1) and widespread degradation of permafrost may subject permafrost C to microbial mineralization and fluxes to the atmosphere, accelerating climate change. Loss of permafrost C can be quantified in situ by measuring the radiocarbon (14C) content of soil and ecosystem respiration, because permafrost C is older (depleted in 14C) than current plant products and soil C cycling operates on timescales of years to centuries. Here, we use 14C analysis of CO2 respired from graminoid tundra in Arctic Alaska to 1) apportion how plant and microbial respiration contribute to ecosystem respiration in spring, summer, and fall, and 2) elucidate the C sources of microbial respiration throughout the year. We used a novel, passive sampling system, capable of trapping diffusive CO2 throughout the active layer of tussock sedge tundra (n=4, from mineral soil to air) over periods of 2 days to 3 weeks in June 2017. CO2 was collected into various sizes of canisters, ranging from 0.5-32 L, and analyzed for its 14C content at UC Irvine's KCCAMS laboratory. To evaluate the system's efficiency, and quantify the temporal and spatial variability of ecosystem respiration sources, we co-deployed 3 Vaisala Carbocap [CO2] and temperature probes, and traditional chambers (n=6) and gas wells (n=10) for sampling of ecosystem- and soil-respired 14CO2 over 15 min-24 hours. A comparison of traditional methods with our new sampler indicates that the system accurately sampled the expected [CO2] depth gradient. The CO2 sampling rate was positively correlated to soil [CO2] (R2=0.963), equivalent to 1.4*10-3±1.6*10-3 mg C/L/month/ppm (n=8). Gas well and probe concentrations were of the same order of magnitude on the same

  1. How to trigger low carbon technologies by EU targets for 2030? An assessment of technology needs

    Energy Technology Data Exchange (ETDEWEB)

    Groenenberg, H.; Van Breevoort, P.; Janeiro, L.; Winkel, T.

    2013-04-15

    The current EU framework for energy and climate policies up to 2020 consists of three headline targets: 20% reduction of GHG emissions compared to 2005, a 20% share of renewable energy in final energy consumption, and 20% primary energy savings compared to baseline developments. While progress on these 2020 targets is mixed, discussions in the EU about climate and energy policies and targets for the period after 2020 have started. Given the long cycles associated to energy and climate investments, agreement on a clear longer-term policy framework is critical to improve visibility for investors and avoid lock-in effects in inefficient or polluting technologies. Therefore, the European Commission published a Communication on 6 June 2012 on the need for a long term policy framework for renewable energy, and a Green Paper on the 2030 climate and energy policy framework on 27 March 2013. Against this background, the Dutch Ministries of Infrastructure and Environment and the Ministry of Economic Affairs requested PBL to create input for the European debate on climate targets and policies until and beyond 2030. Ecofys supported PBL by addressing the following two questions: (1) What steps are needed for selected key technology groups to achieve long term GHG emission reductions and what climate and energy policies are likely to trigger these steps?; and (2) What are the pros and cons of a 2030 policy framework with (a) a GHG reduction target only, and (b) targets for GHG reduction, renewable energy, and energy efficiency? The focus of the first question was on four technology groups, namely (1) energy efficiency in the built environment, notably for heat; (2) solar PV and wind energy; (3) advanced biofuels; (4) CO2 carbon capture and storage (CCS). An analysis of the steps needed for the deployment of the full GHG mitigation potential of the discussed technology groups shows that this will largely depend on the adoption of a wide range of policy instruments by EU Member

  2. An update on anticancer drug development and delivery targeting carbonic anhydrase IX

    Directory of Open Access Journals (Sweden)

    Justina Kazokaitė

    2017-11-01

    Full Text Available The expression of carbonic anhydrase (CA IX is up-regulated in many types of solid tumors in humans under hypoxic and acidic microenvironment. Inhibition of CA IX enzymatic activity with selective inhibitors, antibodies or labeled probes has been shown to reverse the acidic environment of solid tumors and reduce the tumor growth establishing the significant role of CA IX in tumorigenesis. Thus, the development of potent antitumor drugs targeting CA IX with minimal toxic effects is important for the target-specific tumor therapy. Recently, several promising antitumor agents against CA IX have been developed to treat certain types of cancers in combination with radiation and chemotherapy. Here we review the inhibition of CA IX by small molecule compounds and monoclonal antibodies. The methods of enzymatic assays, biophysical methods, animal models including zebrafish and Xenopus oocytes, and techniques of diagnostic imaging to detect hypoxic tumors using CA IX-targeted conjugates are discussed with the aim to overview the recent progress related to novel therapeutic agents that target CA IX in hypoxic tumors.

  3. Carbonates in leaching reactions in context of {sup 14}C dating

    Energy Technology Data Exchange (ETDEWEB)

    Michalska, Danuta, E-mail: danamich@amu.edu.pl [Institute of Geology, Faculty of Geographical and Geological Sciences, Adam Mickiewicz University, ul. Makow Polnych 16, 61-606 Poznan (Poland); Czernik, Justyna, E-mail: justyna.czernik@gmail.com [Poznań Radiocarbon Laboratory, ul. Rubież 46, 61-612 Poznań (Poland)

    2015-10-15

    Lime mortars as a mixture of binder and aggregate may contain carbon of various origins. If the mortars are made of totally burnt lime, radiocarbon dating of binder yields the real age of building construction. The presence of carbonaceous aggregate has a significant influence on the {sup 14}C measurements results and depending on the type of aggregate and fraction they may cause overaging. Another problem, especially in case of hydraulic mortars that continue to be chemically active for a very long time, is the recrystallization usually connected with rejuvenation of the results but also, depending on local geological structures, with so called reservoir effect yielding apparent ages. An attempt in separating the binder from other carbonaceous components successfully was made for samples from Israel by Nawrocka-Michalska et al. (2007). The same preparation procedure, after taking into account the petrographic composition, was used for samples coming from Poland, Nawrocka et al. (2009). To verify the procedure used previously for non-hydraulic samples determination an experimental tests on carbonaceous mortars with crushed bricks from Novae in Bulgaria were made. Additionally, to identify different carbonaceous structures and their morphology, a cathodoluminescence and scanning electron microscope with electron dispersive spectrometer were applied. The crushed bricks and brick dust used in mortars production process have been interpreted as an alternative use to other pozzolanic materials. The reaction between lime and pozzolanic additives take place easily and affects the rate and course of carbonates decomposition in orthophosphric acid, during the samples pretreatment for dating. The composition of the Bulgarian samples together with influence of climate conditions on mortar carbonates do not allow for making straightforward conclusions in chronology context, but gives some new guidelines in terms of hydraulic mortars application for dating. This work has mainly

  4. Carbonates in leaching reactions in context of "1"4C dating

    International Nuclear Information System (INIS)

    Michalska, Danuta; Czernik, Justyna

    2015-01-01

    Lime mortars as a mixture of binder and aggregate may contain carbon of various origins. If the mortars are made of totally burnt lime, radiocarbon dating of binder yields the real age of building construction. The presence of carbonaceous aggregate has a significant influence on the "1"4C measurements results and depending on the type of aggregate and fraction they may cause overaging. Another problem, especially in case of hydraulic mortars that continue to be chemically active for a very long time, is the recrystallization usually connected with rejuvenation of the results but also, depending on local geological structures, with so called reservoir effect yielding apparent ages. An attempt in separating the binder from other carbonaceous components successfully was made for samples from Israel by Nawrocka-Michalska et al. (2007). The same preparation procedure, after taking into account the petrographic composition, was used for samples coming from Poland, Nawrocka et al. (2009). To verify the procedure used previously for non-hydraulic samples determination an experimental tests on carbonaceous mortars with crushed bricks from Novae in Bulgaria were made. Additionally, to identify different carbonaceous structures and their morphology, a cathodoluminescence and scanning electron microscope with electron dispersive spectrometer were applied. The crushed bricks and brick dust used in mortars production process have been interpreted as an alternative use to other pozzolanic materials. The reaction between lime and pozzolanic additives take place easily and affects the rate and course of carbonates decomposition in orthophosphric acid, during the samples pretreatment for dating. The composition of the Bulgarian samples together with influence of climate conditions on mortar carbonates do not allow for making straightforward conclusions in chronology context, but gives some new guidelines in terms of hydraulic mortars application for dating. This work has mainly

  5. Simultaneous detection of multiple DNA targets by integrating dual-color graphene quantum dot nanoprobes and carbon nanotubes.

    Science.gov (United States)

    Qian, Zhaosheng; Shan, Xiaoyue; Chai, Lujing; Chen, Jianrong; Feng, Hui

    2014-12-01

    Simultaneous detection of multiple DNA targets was achieved based on a biocompatible graphene quantum dots (GQDs) and carbon nanotubes (CNTs) platform through spontaneous assembly between dual-color GQD-based probes and CNTs and subsequently self-recognition between DNA probes and targets. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Carbon-14 Specific Activity Model Validation for Biota in Wetland Environments

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Sharp, K.J.; Benz, M.L.; Carr, J.; Killey, R.W.D.

    2008-01-01

    In many cases, contaminants, such as radionuclides, can show highly localized spatial distributions in natural systems. Therefore, a key question for environmental assessment and monitoring becomes, how can these localized distributions of contaminants in the environment lead to organism exposure, and ultimately, the potential for effects to receptor biota? To address this question, an important first step is to conduct field surveys at sites of interest to map out the spatial distribution and extent of contaminants in areas that are being occupied and utilized by resident receptor biota. Work can then be conducted to establish predictive relationships between contaminant concentrations in biota tissues and those in environmental media with which biota interact, to gain an understanding of how representative ambient contaminant concentrations are of biota exposure. The objectives of this study were: - To conduct a field survey in a wetland ecosystem to characterize the spatial distribution of carbon- 14 ( 14 C), a radionuclide with dynamics in natural systems that can be described using a specific activity model; and - To determine whether 14 C concentrations in environmental media reflect those measured in tissues of resident flora and fauna. A detailed field campaign was carried out in summer 2001 to characterize the spatial distribution and areal coverage of 14 C in Duke Swamp, a wetland ecosystem on Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories (CRL) site that receives 14 C through releases from an up-gradient Waste Management Area (WMA), primarily through groundwater influx. Sampling of surface vegetation (dominantly comprised of Sphagnum moss) was conducted at a total of 69 locations, with complementary sampling of air, soil, fungi, aerial insects, ground-dwelling insects, amphibians, small mammals and snakes being carried out at a subset of five locations with varying 14 C concentrations. Concentrations of 14 C in resident Duke Swamp

  7. Carbon-14, tritium, stable isotope and chemical measurements on thermal waters from the Tauranga region

    International Nuclear Information System (INIS)

    Stewart, M.K.; McGill, R.C.; Taylor, C.B.; Whitehead, N.E.; Downes, C.J.

    1984-03-01

    The chemical compositions of groundwater from the Tauranga region are affected to varying degrees by reducing conditions due to buried organic matter. The levels of some dissolved constituents are also affected by mixing with sea water contained within the rocks and by rock-water interaction. Dissolved gas compositions range from oxygen-bearing to methane-bearing reflecting the varying redox conditions. Excess air may be present but further experiments are necessary to confirm this. Apparent ages deduced from carbon-14 measurements (corrected using 12C dilution and 13C fractionation methods) range from 2-25,000 years, suggesting that some of the waters were recharged during late Pleistocene or early Holocene time. ΔD and Δ18 O values of the oldest waters are slightly more negative than those of younger samples; this may indicate recharge during a cooler climate, in agreement with the 14C ages. Very low but significantly non-zero tritium contents (TR=(0.007-0.059)+-0.007) were measured using the high tritium-enrichment facilities at INS and the very low-background counters at the University of Bern. The tritium is thought to derive from contamination or nuclear reactions in the aquifer rocks rather than from recharge water

  8. Use of radio-active carbon (/sup 14/C) for measuring organic production in the sea

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, E S

    1952-01-01

    A method for measuring the photosynthesis of plankton algae in a water sample by means of assimilated /sup 14/C is described. It is shown that the assimilation of /sup 14/C in organic matter otherwise than by photosynthesis is of quite insignificant importance. An account is given of the isotope effect in photosynthesis. Two different methods for the measurement of production of matter per surface unit are described. In the first method samples of water are taken from the various depths and transferred to bottles with glass stoppers. After addition of /sup 14/C, the bottles are suspended at the depths from which the samples were taken, and left there from noon to sunset, for instance. In the other method the bottles are placed in a water-bath which is illuminated by a definite light intensity. The penetration of light in the sea is determined at the same time. The production of matter per surface unit is calculated by means of a formula involving the determination of the depth at which 1 per cent of the total amount of green and blue light occurs, and measurement of the intensities of assimilation in water-bath. The formula, which applies to the tropics, has been derived by comparing the results from all tropical stations, at which observations by the two methods were made simultaneously. The values found for production of matter on a section across the Indian Ocean are recorded. The net production of matter for all sea regions on the globe is estimated at about 1.5 x 10/sup +10/ tons of carbon per year, which is slightly less than the amount produced on land, and the hitherto accepted figures for the production of matter in the sea have proved to be greatly exaggerated.

  9. 14CO2-assimilation, translocation of 14C, and 14C-carbonate uptake in different organs of spring barley plants in relation to adult-plant resistance to powdery mildew

    International Nuclear Information System (INIS)

    Hwang, B.K.; Ibenthal, W.-D.; Heitefuss, R.

    1986-01-01

    The cultivar Peruvian of spring barley, which is susceptible at all growth stages, and Asse, which exhibits adult-plant resistance to powdery mildew, were compared in 14 CO 2 assimilation, distribution of 14 C, and 14 C-carbonate uptake in different organs of healthy and infected plants. The reduction of 14 CO 2 assimilation in infected plants at the first and fourth leaf stages was greater in Peruvian than in Asse. In Peruvian, the 14 C which was fixed by the infected third leaf of plants with mildew on the lower 3 leaves remained in the third leaves with very little translocation to other parts of the plant. Infection of the lower three leaves at the fourth leaf stage reduced 14 CO 2 assimilation in noninfected fourth leaves of Asse less than that of Peruvian, but the flow of 14 C from the healthy fourth leaves into other plant parts such as leaf sheaths was markedly stimulated in Peruvian compared to Asse. Infection also reduced the uptake of 14 C-carbonate by seedling roots, the reduction being greater in Peruvian than Asse. A greater proportion of the 14 C absorbed by roots of Asse was translocated to the infected leaves than that of Peruvian. It was concluded that powdery mildew disrupted the normal pattern of photosynthesis and translocation of metabolites in a susceptible cultivar more markedly than in an adult-plant-resistant cultivar of spring barley. (author)

  10. Engineering Multi-Walled Carbon Nanotube Therapeutic Bionanofluids to Selectively Target Papillary Thyroid Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Idit Dotan

    Full Text Available The incidence of papillary thyroid carcinoma (PTC has risen steadily over the past few decades as well as the recurrence rates. It has been proposed that targeted ablative physical therapy could be a therapeutic modality in thyroid cancer. Targeted bio-affinity functionalized multi-walled carbon nanotubes (BioNanofluid act locally, to efficiently convert external light energy to heat thereby specifically killing cancer cells. This may represent a promising new cancer therapeutic modality, advancing beyond conventional laser ablation and other nanoparticle approaches.Thyroid Stimulating Hormone Receptor (TSHR was selected as a target for PTC cells, due to its wide expression. Either TSHR antibodies or Thyrogen or purified TSH (Thyrotropin were chemically conjugated to our functionalized Bionanofluid. A diode laser system (532 nm was used to illuminate a PTC cell line for set exposure times. Cell death was assessed using Trypan Blue staining.TSHR-targeted BioNanofluids were capable of selectively ablating BCPAP, a TSHR-positive PTC cell line, while not TSHR-null NSC-34 cells. We determined that a 2:1 BCPAP cell:α-TSHR-BioNanofluid conjugate ratio and a 30 second laser exposure killed approximately 60% of the BCPAP cells, while 65% and >70% of cells were ablated using Thyrotropin- and Thyrogen-BioNanofluid conjugates, respectively. Furthermore, minimal non-targeted killing was observed using selective controls.A BioNanofluid platform offering a potential therapeutic path for papillary thyroid cancer has been investigated, with our in vitro results suggesting the development of a potent and rapid method of selective cancer cell killing. Therefore, BioNanofluid treatment emphasizes the need for new technology to treat patients with local recurrence and metastatic disease who are currently undergoing either re-operative neck explorations, repeated administration of radioactive iodine and as a last resort external beam radiation or chemotherapy, with

  11. SMART marine goals, targets and management - Is SDG 14 operational or aspirational, is 'Life Below Water' sinking or swimming?

    Science.gov (United States)

    Cormier, Roland; Elliott, Michael

    2017-10-15

    The United Nations Sustainable Development Goals (SDG), adopted in September 2015, are accompanied by targets which have to be met individually and collectively by the signatory states. SDG14 Life Below Water aims to lay the foundation for the integrated and sustainable management of the oceans. However, any environmental management has to be based around targets which are SMART - specific, measurable, achievable, realistic and time bounded - otherwise it is not possible to determine whether management actions are successful and achieve the desired aims. The discussion here shows that many of the targets adopted for SDG14, and especially a detailed analysis of Target 1, are aspirational rather than fully quantified. In order to move towards making the targets operational, we advocate merging the language of environmental management with that used by industry for linking risks to the environment, management performance and ensuing controls. By adopting an approach which uses Key Performance Indicators ('KPIs'), Key Risk Indicators ('KRIs') and Key Control Indicators ('KCIs'), we advocate that a degree of rigour leading to defendable actions can be brought to marine management. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. TWEAK/Fn14 axis: a promising target for the treatment of cardiovascular diseases.

    Directory of Open Access Journals (Sweden)

    Luis Miguel Blanco-Colio

    2014-01-01

    Full Text Available Cardiovascular diseases (CVD are the first cause of mortality in Western countries. CVD include several pathologies such as coronary heart disease, stroke or cerebrovascular accident, congestive heart failure, peripheral arterial disease and aortic aneurysm, among others. Interaction between members of the tumor necrosis factor (TNF superfamily and their receptors elicits several biological actions that could participate in CVD. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK and its functional receptor, fibroblast growth factor-inducible molecule 14 (Fn14, are two proteins belonging to the TNF superfamily that activate NF-κB by both canonical and non-canonical pathways and regulate several cell functions such as proliferation, migration, differentiation, cell death, inflammation, and angiogenesis. TWEAK/Fn14 axis plays a beneficial role in tissue repair after acute injury. However, persistent TWEAK/Fn14 activation mediated by blocking experiments or overexpression experiments in animal models has shown an important role of this axis in the pathological remodeling underlying CVD. In this review, we summarize the role of TWEAK/Fn14 pathway in the development of CVD, focusing on atherosclerosis and stroke and the molecular mechanisms by which TWEAK/Fn14 interaction participates in these pathologies. We also review the role of the soluble form of TWEAK as a biomarker for the diagnosis and prognosis of CVD. Finally, we highlight the results obtained with other members of the TNF superfamily that also activate canonical and non-canonical NF-κB pathway.

  13. Diffusion-type model of the global carbon cycle for the estimation of dose to the world population from releases of carbon-14 to the atmosphere

    International Nuclear Information System (INIS)

    Killough, G.G.

    1977-05-01

    A nonlinear dynamic model of the exchange of carbon among the atmosphere, terrestrial biosphere, and ocean is described and applied to estimating the radiation dose to the world's population from the release of 14 C to the atmosphere from the nuclear power industry. A computer implementation of the model, written in the IBM Continuous System Modeling Program III (CSMP III) simulation language, is presented. The model treats the ocean as a diffusive medium with respect to vertical transport of carbon, and the nonlinear variation of CO 2 partial pressure with the total inorganic carbon concentration in surface waters is taken into account in calculating the transfer rate from ocean to atmosphere. Transfers between the atmosphere and terrestrial biosphere are represented by nonlinear equations which consider CO 2 fertilization and impose a constraint on the ultimate total carbon mass in the biosphere

  14. Synthesis of deleobuvir, a potent hepatitis C virus polymerase inhibitor, and its major metabolites labeled with carbon-13 and carbon-14.

    Science.gov (United States)

    Latli, Bachir; Hrapchak, Matt; Chevliakov, Maxim; Li, Guisheng; Campbell, Scot; Busacca, Carl A; Senanayake, Chris H

    2015-05-30

    Deleobuvir, (2E)-3-(2-{1-[2-(5-bromopyrimidin-2-yl)-3-cyclopentyl-1-methyl-1H-indole-6-carboxamido]cyclobutyl}-1-methyl-1H-benzimidazol-6-yl)prop-2-enoic acid (1), is a non-nucleoside, potent, and selective inhibitor of hepatitis C virus NS5B polymerase. Herein, we describe the detailed synthesis of this compound labeled with carbon-13 and carbon-14. The synthesis of its three major metabolites, namely, the reduced double bond metabolite (2) and the acyl glucuronide derivatives of (1) and (2), is also reported. Aniline-(13) C6 was the starting material to prepare butyl (E)-3-(3-methylamino-4-nitrophenyl-(13) C6 )acrylate [(13) C6 ]-(11) in six steps. This intermediate was then used to obtain [(13) C6 ]-(1) and [(13) C6 ]-(2) in five and four more steps, respectively. For the radioactive synthesis, potassium cyanide-(14) C was used to prepare 1-cylobutylaminoacid [(14) C]-(23) via Buchrer-Bergs reaction. The carbonyl chloride of this acid was then used to access both [(14) C]-(1) and [(14) C]-(2) in four steps. The acyl glucuronide derivatives [(13) C6 ]-(3), [(13) C6 ]-(4) and [(14) C]-(3) were synthesized in three steps from the acids [(13) C6 ]-(1), [(13) C6 ]-(2) and [(14) C]-(1) using known procedures. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Framework for the analysis of the low-carbon scenario 2020 to achieve the national carbon Emissions reduction target: Focused on educational facilities

    International Nuclear Information System (INIS)

    Koo, Choongwan; Kim, Hyunjoong; Hong, Taehoon

    2014-01-01

    Since the increase in greenhouse gas emissions has increased the global warming potential, an international agreement on carbon emissions reduction target (CERT) has been formulated in Kyoto Protocol (1997). This study aimed to develop a framework for the analysis of the low-carbon scenario 2020 to achieve the national CERT. To verify the feasibility of the proposed framework, educational facilities were used for a case study. This study was conducted in six steps: (i) selection of the target school; (ii) establishment of the reference model for the target school; (iii) energy consumption pattern analysis by target school; (iv) establishment of the energy retrofit model for the target school; (v) economic and environmental assessment through the life cycle cost and life cycle CO 2 analysis; and (vi) establishment of the low-carbon scenario in 2020 to achieve the national CERT. This study can help facility managers or policymakers establish the optimal retrofit strategy within the limited budget from a short-term perspective and the low-carbon scenario 2020 to achieve the national CERT from the long-term perspective. The proposed framework could be also applied to any other building type or country in the global environment

  16. The complex transfer reaction (14C, 15O) on Ni, Zn and Ge targets: existence and mass of 69Ni

    International Nuclear Information System (INIS)

    Dessagne, P.; Bernas, M.; Langevin, M.; Pougheon, F.; Roussel, P.; Morrison, G.C.

    1984-01-01

    The ( 14 C, 15 O) complex transfer reaction has been studied at 72 MeV incident energy on 58 Ni, 60 Ni, 62 Ni, 64 Ni, 68 Zn, 70 Zn and 74 Ge, 76 Ge targets. Spectra and differential cross sections have been measured in a 5 0 angular range centred around a laboratory angle of 6 0 . The nucleus 69 Ni has been observed and its mass determined for the first time

  17. Towards a global understanding of vertical soil carbon dynamics: meta-analysis of soil 14C data

    Science.gov (United States)

    hatte, C.; Balesdent, J.; Guiot, J.

    2012-12-01

    Soil represents the largest terrestrial storage mechanism for atmospheric carbon from photosynthesis, with estimates ranging from 1600 Pg C within the top 1 meter to 2350 Pg C for the top 3 meters. These values are at least 2.5 times greater than atmospheric C pools. Small changes in soil organic carbon storage could result in feedback to atmospheric CO2 and the sensitivity of soil organic matter to changes in temperature, and precipitation remains a critical area of research with respect to the global carbon cycle. As an intermediate storage mechanism for organic material through time, the vertical profile of carbon generally shows an age continuum with depth. Radiocarbon provides critical information for understanding carbon exchanges between soils and atmosphere, and within soil layers. Natural and "bomb" radiocarbon has been used to demonstrate the importance and nature of the soil carbon response to climatic and human impacts on decadal to millennial timescales. Radiocarbon signatures of bulk, or chemically or physically fractionated soil, or even of specific organic compounds, offer one of the only ways to infer terrestrial carbon turnover times or test ecosystem carbon models. We compiled data from the literature on radiocarbon distribution on soil profiles and characterized each study according to the following categories: soil type, analyzed organic fraction, location (latitude, longitude, elevation), climate (temperature, precipitation), land use and sampling year. Based on the compiled data, soil carbon 14C profiles were reconstructed for each of the 226 sites. We report here partial results obtained by statistical analyses of portion of this database, i.e. bulk and bulk-like organic matter and sampling year posterior to 1980. We highlight here 14C vertical pattern in relationship with external parameters (climate, location and land use).

  18. Systematical investigations of the emission of carbon 14 from a TRIGA-Mark-II reactor - methods and results

    International Nuclear Information System (INIS)

    Pfeiffer, K.J.

    1981-01-01

    Almost no information is available about the extent of the carbon-14 releases from a research reactor. For this reason this report is dealing with the emission of C-14 from the Vienna TRIGA-Mark-II reactor. In addition the resulting radiation exposure is estimated. Due to the low activity concentrations of C-14 in research reactor effluents special requirements are necessary for sampling and measuring. A technique providing both sufficient lower limit of detection and little effort of sample preparation was developed. Carbon dioxide was trapped by bubbling air taken from the stack through washing bottles containing an aqueous solution of sodium hydroxide. After sampling a precipitate of CaCO 3 was formed and about 8 g of calcium carbonate were counted as a gel suspension by liquid scintillation counting. The formation of the gel was provided by mixing water with a scintillation cocktail originally developed for uptake of high quantities of aqueous solutions. The resulting lower limit of detection was about 50 Bq/kg carbon being equivalent to 9mBq/m 3 air. Concluding the measurements, which were carried out by weekly counting and a period of some 14 months, a normalized release rate of about 280 Bq (7, 1μCi) was found. This release rate is somewhat higher than the reported values for power reactors, because the main activity is produced by activation of air in experimental equipments. (author)

  19. Carbon-14 dating of a mummy from 'Caverna da Babilonia', Rio Novo Country, south of Minas Gerais (MG, Brazil)

    International Nuclear Information System (INIS)

    Beltrao, M. da C.M.C.; Danon, J.; Poupeau, G.

    1985-01-01

    The vegetable fibers of a cloth wrapping a mummy of a woman, found in 'Caverna da Babilonia' (MG, Brazil), were dated with carbon-14. There is strong evidence that it is a pre-colombian mummym since the age of the sample is 600 + - 80 years (1σ). (C.L.B.) [pt

  20. Hyaluronic acid-functionalized single-walled carbon nanotubes as tumor-targeting MRI contrast agent

    Directory of Open Access Journals (Sweden)

    Hou L

    2015-07-01

    Full Text Available Lin Hou,* Huijuan Zhang,* Yating Wang, Lili Wang, Xiaomin Yang, Zhenzhong ZhangSchool of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, People’s Republic of China*These authors contributed equally to this workAbstract: A tumor-targeting carrier, hyaluronic acid (HA-functionalized single-walled carbon nanotubes (SWCNTs, was explored to deliver magnetic resonance imaging (MRI contrast agents (CAs targeting to the tumor cells specifically. In this system, HA surface modification for SWCNTs was simply accomplished by amidation process and could make this nanomaterial highly hydrophilic. Cellular uptake was performed to evaluate the intracellular transport capabilities of HA-SWCNTs for tumor cells and the uptake rank was HA-SWCNTs> SWCNTs owing to the presence of HA, which was also evidenced by flow cytometry. The safety evaluation of this MRI CAs was investigated in vitro and in vivo. It revealed that HA-SWCNTs could stand as a biocompatible nanocarrier and gadolinium (Gd/HA-SWCNTs demonstrated almost no toxicity compared with free GdCl3. Moreover, GdCl3 bearing HA-SWCNTs could significantly increase the circulation time for MRI. Finally, to investigate the MRI contrast enhancing capabilities of Gd/HA-SWCNTs, T1-weighted MR images of tumor-bearing mice were acquired. The results suggested Gd/HA-SWCNTs had the highest tumor-targeting efficiency and T1-relaxivity enhancement, indicating HA-SWCNTs could be developed as a tumor-targeting carrier to deliver the CAs, GdCl3, for the identifiable diagnosis of tumor.Keywords: gadolinium, magnetic resonance, SWCNTs, hyaluronic acid, contrast agent

  1. Low-density carbonized composite foams for direct-drive laser ICF targets

    International Nuclear Information System (INIS)

    Kong, Fung-Ming.

    1989-03-01

    The design for a direct-drive, high-gain laser inertial confinement fusion target calls for the use of a low-density, low-atomic-number foam to confine and stabilize liquid deuterium-tritium (DT) in a spherical-shell configuration. Over the past two years, we have successfully developed polystyrene foams (PS) and carbonized resorcinol-formaldehyde foams (CRF) for that purpose. Both candidates are promising materials with unique characteristics. PS has superior mechanical strength and machinability, but its relatively large thermal contraction is a significant disadvantage. CRF has outstanding wettability and dimensional stability in liquid DT; yet it is much more fragile than PS. To combine the strengths of both materials, we have recently developed a polymer composite foam which exceeds PS in mechanical strength, but retains the wettability and dimension stability of CRF. This paper will discuss the preparation, structure, and properties of the polymer composite foams. 5 refs., 1 fig., 1 tab

  2. Effects of functionalization on the targeting site of carbon nanotubes inside cells

    International Nuclear Information System (INIS)

    Porter, A E; Bendall, J S; Welland, M; Gass, M; Muller, K; Skepper, J; Midgley, P

    2010-01-01

    Functionalized single-walled carbon nanotubes (SWNTs) are currently being investigated for a variety of applications, including contrast agents for medical imaging 1 . However before they can be used commercially it is necessary to assess whether they enter cells, the site they target within the cell and whether they cause any cytotoxicity. Here we characterize uptake of unlabelled, acid-treated, COO - functionalized SWNTs by human monocyte derived macrophage cells using both low-loss and energy loss spectroscopy and compare our findings to previous work on unpurified SWNTs. The acid-treated SWNTs were less aggregated within cells than unpurified SWNTs. Acid treatment was found to affect the distribution of intracellular SWNTs. Bundles, and also individual acid treated SWNTs, were found frequently inside lysosomes, cytoplasm and also inserting into the plasma membrane whereas unpurified non-functionalised SWNTs entered lysosomes and occasionally the nucleus.

  3. Effects of functionalization on the targeting site of carbon nanotubes inside cells

    Energy Technology Data Exchange (ETDEWEB)

    Porter, A E; Bendall, J S; Welland, M [UK SuperSTEM, Daresbury Laboratory, Daresbury, Cheshire WA4 4AD (United Kingdom); Gass, M [The Nanoscience Centre, University of Cambridge, 11 J. J. Thompson Avenue, Cambridge CB3 OFF (United Kingdom); Muller, K; Skepper, J [Multiimaging Centre, Department of PDN, Physiology, Development and Neuroscience, Anatomy Building, University of Cambridge, Downing Street, Cambridge CB2 3DY (United Kingdom); Midgley, P, E-mail: a.porter@imperial.ac.u [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)

    2010-07-01

    Functionalized single-walled carbon nanotubes (SWNTs) are currently being investigated for a variety of applications, including contrast agents for medical imaging{sup 1}. However before they can be used commercially it is necessary to assess whether they enter cells, the site they target within the cell and whether they cause any cytotoxicity. Here we characterize uptake of unlabelled, acid-treated, COO{sup -} functionalized SWNTs by human monocyte derived macrophage cells using both low-loss and energy loss spectroscopy and compare our findings to previous work on unpurified SWNTs. The acid-treated SWNTs were less aggregated within cells than unpurified SWNTs. Acid treatment was found to affect the distribution of intracellular SWNTs. Bundles, and also individual acid treated SWNTs, were found frequently inside lysosomes, cytoplasm and also inserting into the plasma membrane whereas unpurified non-functionalised SWNTs entered lysosomes and occasionally the nucleus.

  4. [Quantifying rice (Oryza sativa L.) photo-assimilated carbon input into soil organic carbon pools following continuous 14C labeling].

    Science.gov (United States)

    Nie, San-An; Zhou, Ping; Ge, Ti-Da; Tong, Cheng-Li; Xiao, He-Ai; Wu, Jin-Shui; Zhang, Yang-Zhu

    2012-04-01

    The microcosm experiment was carried out to quantify the input and distribution of photo-assimilated C into soil C pools by using a 14C continuous labeling technique. Destructive samplings of rice (Oryza sativa) were conducted after labeling for 80 days. The allocation of 14C-labeled photosynthates in plants and soil C pools such as dissolved organic C (DOC) and microbial biomass C (MBC) in rice-planted soil were examined over the 14C labeling span. The amounts of rice shoot and root biomass C was ranged from 1.86 to 5.60 g x pot(-1), 0.46 to 0.78 g x pot(-1) in different tested paddy soils after labeling for 80 days, respectively. The amount of 14C in the soil organic C (14C-SOC) was also dependent on the soils, ranged from 114.3 to 348.2 mg x kg(-1), accounting for 5.09% to 6.62% of the rice biomass 14C, respectively. The amounts of 14C in the dissolved organic C (14C-DOC) and in the microbial biomass C(14C-MBC), as proportions of 14C-SOC, were 2.21%-3.54% and 9.72% -17.2%, respectively. The 14C-DOC, 14C-MBC, and 14C-SOC as proportions of total DOC, MBC, and SOC, respectively, were 6.72% -14.64%, 1.70% -7.67%, and 0.73% -1.99%, respectively. Moreover, the distribution and transformation of root-derived C had a greater influence on the dynamics of DOC and MBC than on the dynamics of SOC. Further studies are required to ascertain the functional significance of soil microorganisms (such as C-sequestering bacteria and photosynthetic bacteria) in the paddy system.

  5. Multimolecular tracers of terrestrial carbon transfer across the pan-Arctic: 14C characteristics of sedimentary carbon components and their environmental controls

    Science.gov (United States)

    Feng, Xiaojuan; Gustafsson, Örjan; Holmes, R. Max; Vonk, Jorien E.; van Dongen, Bart E.; Semiletov, Igor P.; Dudarev, Oleg V.; Yunker, Mark B.; Macdonald, Robie W.; Wacker, Lukas; Montluçon, Daniel B.; Eglinton, Timothy I.

    2015-11-01

    Distinguishing the sources, ages, and fate of various terrestrial organic carbon (OC) pools mobilized from heterogeneous Arctic landscapes is key to assessing climatic impacts on the fluvial release of carbon from permafrost. Through molecular 14C measurements, including novel analyses of suberin- and/or cutin-derived diacids (DAs) and hydroxy fatty acids (FAs), we compared the radiocarbon characteristics of a comprehensive suite of terrestrial markers (including plant wax lipids, cutin, suberin, lignin, and hydroxy phenols) in the sedimentary particles from nine major arctic and subarctic rivers in order to establish a benchmark assessment of the mobilization patterns of terrestrial OC pools across the pan-Arctic. Terrestrial lipids, including suberin-derived longer-chain DAs (C24,26,28), plant wax FAs (C24,26,28), and n-alkanes (C27,29,31), incorporated significant inputs of aged carbon, presumably from deeper soil horizons. Mobilization and translocation of these "old" terrestrial carbon components was dependent on nonlinear processes associated with permafrost distributions. By contrast, shorter-chain (C16,18) DAs and lignin phenols (as well as hydroxy phenols in rivers outside eastern Eurasian Arctic) were much more enriched in 14C, suggesting incorporation of relatively young carbon supplied by runoff processes from recent vegetation debris and surface layers. Furthermore, the radiocarbon content of terrestrial markers is heavily influenced by specific OC sources and degradation status. Overall, multitracer molecular 14C analysis sheds new light on the mobilization of terrestrial OC from arctic watersheds. Our findings of distinct ages for various terrestrial carbon components may aid in elucidating fate of different terrestrial OC pools in the face of increasing arctic permafrost thaw.

  6. The history of ironware in Japan revealed by the AMS-carbon 14 age method

    International Nuclear Information System (INIS)

    Fujio, Shin'ichirou

    2005-01-01

    This paper focuses on the influence what the AMS-carbon 14 age method attains to the history of the iron in the Japanese Islands. The research team in National Museum of Japanese History makes a clear that the Yayoi period began in 10 Cen. cal BC. However, there was a problem in this. It is iron. If the Yayoi period has started in the 10th Cen. BC, it means that the ironware in Japanese Islands had spread early rather than it spreads in China. The research team reexamined the ironware excavated from Magarita site in the Fukuoka Pref. considered to be the oldest ironware in Japan. Consequently, the excavation situation was indefinite and it turned out that we cannot specify the time to belong. Furthermore, 36 ironwares in the initial and early Yayoi were also already found by that time cannot be specified except for two points. Therefore, it turned out that Japanese ironware appeared in the 3rd century of B.C. What does this mean? Although it had been thought that the beginning of agriculture in Japan and the appearance of ironware were simultaneous, it turned out that agriculture has appeared early about in 700 years. Therefore, it became clear that agriculture of Japan started at the Stone Age. (author)

  7. Synthesis of carbon-14 labelled (5Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone:

    DEFF Research Database (Denmark)

    Persson, T.; Johansen, S.K.; Martiny, L.

    2004-01-01

    The potent quorum sensing inhibitor (5Z)-4-bromo-5-(bromomethylene)-2(5H)-[2-C-14]furanone has been prepared in five steps in 7.7% overall yield starting from bromo[1-C-14]acetic acid. Condensation of ethyl bromo[1-C-14]acetate with ethyl acetoacetate followed by decarboxylation was accelerated...... by microwave heating to afford [1-C-14]levulinic acid. Subsequently, bromination and oxidation gave the targeted furan-2-one with a radiochemical purity of > 97% and a specific activity of 57 mCi/mmol....

  8. A study for the fabulously of introducing an acceleration mass spectrometer facility (ABMs) for carbon-14 applications

    International Nuclear Information System (INIS)

    Aly, A.I.M.; Comsan, N.; Sadek, M.

    2004-01-01

    In this work a study was conducted to show the importance and feasibility of introducing an accelerating mass spectrometer facility for carbon-14 analysis in the environmental levels. The different applications of Carbon-14 (e.g. dating and identification of food additives of synthetic origin) are discussed. There are two methods for C- 14 measurements, beta decay counting and accelerator mass spectrometry (AMS). The beta decay method requires gram quantities of the sample carbon, compared to few milligram quantities in case of AMS method. The Central Lab. for Environmental Isotope Hydrology of the National Center for Nuclear Safety and Radiation Control has a Carbon-14 analysis facility based on beta decay counting using a liquid scintillation counter after sample preparation in the form of benzene through rather complicated chemical conversion steps. This strongly limits the capacity of the laboratory to about 100-150 samples per year. Also, the amount of sample required limits our expansion for some very important applications like dating of archaeological small samples and especially old bone samples which normally have a low concentration of organic compounds. These applications are only possible by using the AMS method. For some applications only AMS could be used e.g measuring C-14 in atmospheric gases such as methane and carbon dioxide is virtually impossible using decay counting but quite feasible with AMS. The importance of purchasing an AMS facility or upgrading the existing accelerator is discussed in view of the shortage of such a facility in Africa and the Middle East. Acquiring an AMS in Egypt will make it possible to accurately date the Egyptian antiquities and to act as a regional laboratory and to enter into new applications where the amount of sample is limiting

  9. 14-3-3 zeta is a molecular target in guggulsterone induced apoptosis in Head and Neck cancer cells

    International Nuclear Information System (INIS)

    Macha, Muzafar A; Matta, Ajay; Chauhan, SS; Siu, KW Michael; Ralhan, Ranju

    2010-01-01

    The five-year survival rates for head and neck squamous cell carcinoma (HNSCC) patients are less than 50%, and the prognosis has not improved, despite advancements in standard multi-modality therapies. Hence major emphasis is being laid on identification of novel molecular targets and development of multi-targeted therapies. 14-3-3 zeta, a multifunctional phospho-serine/phospho-threonine binding protein, is emerging as an effector of pro-survival signaling by binding to several proteins involved in apoptosis (Bad, FKHRL1 and ASK1) and may serve as an appropriate target for head and neck cancer therapy. Herein, we determined effect of guggulsterone (GS), a farnesoid X receptor antagonist, on 14-3-3 zeta associated molecular pathways for abrogation of apoptosis in head and neck cancer cells. Head and neck cancer cells were treated with guggulsterone (GS). Effect of GS-treatment was evaluated using cell viability (MTT) assay and apoptosis was verified by annexin V, DNA fragmentation and M30 CytoDeath antibody assay. Mechanism of GS-induced apoptosis was determined by western blotting and co-IP assays using specific antibodies. Using in vitro models of head and neck cancer, we showed 14-3-3 zeta as a key player regulating apoptosis in GS treated SCC4 cells. Treatment with GS releases BAD from the inhibitory action of 14-3-3 zeta in proliferating HNSCC cells by activating protein phosphatase 2A (PP2A). These events initiate the intrinsic mitochondrial pathway of apoptosis, as revealed by increased levels of cytochrome c in cytoplasmic extracts of GS-treated SCC4 cells. In addition, GS treatment significantly reduced the expression of anti-apoptotic proteins, Bcl-2, xIAP, Mcl1, survivin, cyclin D1 and c-myc, thus committing cells to apoptosis. These events were followed by activation of caspase 9, caspase 8 and caspase 3 leading to cleavage of its downstream target, poly-ADP-ribose phosphate (PARP). GS targets 14-3-3 zeta associated cellular pathways for reducing

  10. In situ synthesis of N and Cu functionalized mesoporous FDU-14 resins and carbons for electrochemical hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Kong, AiGuo; Wang, WenJuan; Yang, Fan; Ding, HanMing; Shan, YongKui [Department of Chemistry, East China Normal University, ShangHai 200062 (China)

    2010-07-15

    N and Cu cooperatively functionalized mesoporous resin and carbon materials with bicontinuous cubic structure (FDU-14) were obtained by a novel synthesis method. In this method, block copolymers were used as the templates as well as the precursors for the preparation of these modifying mesoporous materials. The CuC{sub 2}O{sub 4} in the channels of mesoporous FDU-14 resins was gotten by in situ oxidation of the templates in a catalytic redox system containing Cu{sup 2+}, Al{sup 3+}, NO{sub 3}{sup -}, PO{sub 4}{sup 3-}, SO{sub 4}{sup 2-} ions. Simultaneously, the phenol-formaldehyde resin frameworks were in situ functionalized by the amine group resulting from the reduction of NO{sub 3}{sup -}, leading to the formation of N and CuC{sub 2}O{sub 4} modified mesoporous FDU-14 resin materials. Its pyrolysis at the different temperatures resulted in the production of N and Cu cooperatively functionalized mesoporous FDU-14 resin and carbon materials. The structure and composition of these materials were characterized by the X-ray power diffraction, transmission electron microscopy, N{sub 2} adsorption-desorption analysis, X-ray photoelectron spectroscopy, infrared spectroscopy, thermogravimetry analysis, and inductive coupled plasma emission spectroscopy. The electrochemical measurement indicated that N and Cu cooperatively functionalized mesoporous FDU-14 carbon materials possessed the enhanced electrochemical hydrogen storage performance. (author)

  11. Carbon-14 in the biosphere: Modeling and supporting research for the Canadian Nuclear Fuel Waste Management program

    International Nuclear Information System (INIS)

    Sheppard, S.C.; Amiro, B.D.; Sheppard, M.I.; Stephenson, M.; Zach, R.; Bird, G.A.

    1994-01-01

    Carbon-14 stands apart from most of the radionuclides present in nuclear fuel waste for several reasons. It has a relatively long radiological half-life and low retardation by granitic geological media so that 14 C is superceded only by 36 Cl and 129 I in potential release to the biosphere from unprocessed used fuel. In the biosphere, its importance continues because it is readily incorporated into the carbon compounds of life. Much of the behavior of 14 C in the biosphere can be conceptualized as isotopic exchange, where the 14 C mixes with 12 C from the biosphere. However, because of lack of data, the authors model the behavior of 14 C only partly as isotopic exchange, with most of the calculations relying on compartment transfer models. The authors experimental work has shown that soil-to-plant transfer may be dominated by the soil-atmosphere-plant pathway. Gaseous loss of 14 C from soils and lakes is significant. However, recalcitrant forms may persist in soils and sediments for long time periods. The impact of these forms is expected to be relatively low because their bioavailability is correspondingly low. Future research should be directed to support full modeling of 14 C as a series of isotopic exchange processes

  12. Physical consequences of the mitochondrial targeting of single-walled carbon nanotubes probed computationally

    Science.gov (United States)

    Chistyakov, V. A.; Zolotukhin, P. V.; Prazdnova, E. V.; Alperovich, I.; Soldatov, A. V.

    2015-06-01

    Experiments by F. Zhou and coworkers (2010) [16] showed that mitochondria are the main target of the cellular accumulation of single-walled carbon nanotubes (SWCNTs). Our in silico experiments, based on geometrical optimization of the system consisting of SWCNT+proton within Density Functional Theory, revealed that protons can bind to the outer side of SWCNT so generating a positive charge. Calculation results allow one to propose the following mechanism of SWCNTs mitochondrial targeting. SWCNTs enter the space between inner and outer membranes of mitochondria, where the excess of protons has been formed by diffusion. In this compartment SWCNTs are loaded with protons and acquire positive charges distributed over their surface. Protonation of hydrophobic SWCNTs can also be carried out within the mitochondrial membrane through interaction with the protonated ubiquinone. Such "charge loaded" particles can be transferred as "Sculachev ions" through the inner membrane of the mitochondria due to the potential difference generated by the inner membrane. Physiological consequences of the described mechanism are discussed.

  13. Plasmonic welded single walled carbon nanotubes on monolayer graphene for sensing target protein

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jangheon; Kim, Soohyun [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong, Yuseong, Daejeon 305-806 (Korea, Republic of); Kim, Gi Gyu; Jung, Wonsuk, E-mail: wonsuk81@wku.ac.kr [Department of Mechanical and Automotive Engineering, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of)

    2016-05-16

    We developed plasmonic welded single walled carbon nanotubes (SWCNTs) on monolayer graphene as a biosensor to detect target antigen molecules, fc fusion protein without any treatment to generate binder groups for linker and antibody. This plasmonic welding induces atomic networks between SWCNTs as junctions containing carboxylic groups and improves the electrical sensitivity of a SWCNTs and the graphene membrane to detect target protein. We investigated generation of the atomic networks between SWCNTs by field-emission scanning electron microscopy and atomic force microscopy after plasmonic welding process. We compared the intensity ratios of D to G peaks from the Raman spectra and electrical sheet resistance of welded SWCNTs with the results of normal SWCNTs, which decreased from 0.115 to 0.086 and from 10.5 to 4.12, respectively. Additionally, we measured the drain current via source/drain voltage after binding of the antigen to the antibody molecules. This electrical sensitivity of the welded SWCNTs was 1.55 times larger than normal SWCNTs.

  14. NMR signal analysis in the large COMPASS $^{14}$NH$_{3}$ target

    CERN Document Server

    Koivuniemi, J; Hess, C; Kisselev, Y U; Meyer, W; Radtke, E; Reicherz, G; Doshita, N; Iwata, T; Kondo, K; Michigami, T

    2009-01-01

    In the large COMPASS polarized proton target the 1508 cm$^{3}$ of irradiated granular ammonia is polarized with dynamic nuclear polarization method using 4 mm microwaves in 2.5 T eld. The nuclear polarization up to 90 - 93 % is determined with cw NMR. The properties of the observed ammonia proton signals are described and spin thermodynamics in high elds is presented. Also the second moment of the NMR line is estimated.

  15. A water-cooled target of a 14 MeV neutron source

    International Nuclear Information System (INIS)

    Ogawa, Masuro; Seki, Masahiro; Kawamura, Hiroshi; Sanokawa, Konomo

    1979-09-01

    For the cooling system of a stationary target for the fusion neutronics source (FNS), designed to meet the structural, thermal and hydraulic requirements, thermohydraulic experiments were made. In the heat transfer experiment, in place of an accelerator, electric-heater assemblies were used. The relation of head loss and heat transfer was obtained as a function of Reynolds number. The head loss was not large for flow rates up to 1.3 l/s. Neither vibration of the apparatus nor cavitation of water was observed even at the maximum flow rate. The heat load of 1 kW for the beam diameter of 15mm, i.e. the requirement of FNS, could be removed by 0.2 l/s water flow, with the target-surface maximum temperature kept below 200 0 C. Extrapolation of the experimental results showed that with the target system, the maximum heat load is 2.3 kW for the beam of diameter 15 mm. The value is sufficiently large compared with the heat load of FNS; with finned cooling surfaces, the heat loads up to 3.7 kW may be removed. (author)

  16. miR-150-5p inhibits hepatoma cell migration and invasion by targeting MMP14.

    Directory of Open Access Journals (Sweden)

    Tao Li

    Full Text Available Hepatocellular carcinoma (HCC is one of the leading causes of cancer-related mortality worldwide. Despite progress in diagnostics and treatment of HCC, its prognosis remains poor because the molecular mechanisms underlying hepatocarcinogenesis are not well understood. In the study, we focused on identifying the role of miRNAs in HCC progression. miRNA microarray was used to analyze the differentially expressed miRNAs, and the results were validated by qPCR. We found that the miR-150-5p expression is down-regulated in HCC tissues compared with pair non-tumor tissues. miR-150-5p expression is also decreased in metastatic cancer tissues compared with pair primary tissues, indicating that miR-150-5p may be involved in HCC metastasis. Functionally, miR-150-5p inhibition significantly promotes hepatoma cell migration and invasion, whereas miR-150-5p overexpression suppresses cancer cell migration and invasion in vitro. The matrix metalloproteinase 14 (MMP14 is identified as a new target gene of miR-150-5p. miR-150-5p markedly inhibits MMP14 expression in hepatoma cells, and miR-150-5p expression is negative correlation with MMP14 expression in vivo. More important, re-expression of MMP14 in hepatoma cells partially reverses the effect of miR-150-5p in inhibiting cell invasion.

  17. Carbon transfer between 2 1/4 Cr 1 Mo alloy and austenitic steels (experiments in anisothermal loops)

    International Nuclear Information System (INIS)

    Baque, P.; Besson, M.; Champeix, L.; Donati, J.R.; Oberlin, C.; Saint-Paul, P.

    1976-01-01

    Studies on carbon transfer between the ferritic steel 2 1/4 Cr 1 Mo and the austenitic steels 316L and 321H have shown that there is not any measurable carbon transfer in the operating conditions of the secondary circuit of PHENIX (475 deg C was the maximal temperature of the 2 1/4 Cr 1 Mo steel). A significant carbon transfer has been observed between the ferritic steel and the 316L steel when the 321H was replaced by the 2 1/4 Cr 1 Mo steel in the same thermohydraulic conditions (the ferritic steel was then used up to 545 deg C). This experiment has demonstrated the importance of the temperature and the initial carbon content of the ferritic steel as parameters in the decarburization process. It appears that decarburization may not be sensitive to the thermohydraulic conditions at least in the range investigated in those experiments. In the other hand the 316L steel is observed to have been carburized, the degree of carburization remaining appreciably constant and independent on the temperature between 400 deg C and 550 deg C [fr

  18. Keratin 23, a novel DPC4/Smad4 target gene which binds 14-3-3ε

    International Nuclear Information System (INIS)

    Liffers, Sven-T; Schwarte-Waldhoff, Irmgard; Meyer, Helmut E; Stühler, Kai; Hahn, Stephan A; Maghnouj, Abdelouahid; Munding, Johanna B; Jackstadt, René; Herbrand, Ulrike; Schulenborg, Thomas; Marcus, Katrin; Klein-Scory, Susanne; Schmiegel, Wolff

    2011-01-01

    Inactivating mutations of SMAD4 are frequent in metastatic colorectal carcinomas. In previous analyses, we were able to show that restoration of Smad4 expression in Smad4-deficient SW480 human colon carcinoma cells was adequate to suppress tumorigenicity and invasive potential, whereas in vitro cell growth was not affected. Using this cellular model system, we searched for new Smad4 targets comparing nuclear subproteomes derived from Smad4 re-expressing and Smad4 negative SW480 cells. High resolution two-dimensional (2D) gel electrophoresis was applied to identify novel Smad4 targets in the nuclear subproteome of Smad4 re-expressing SW480 cells. The identified candidate protein Keratin 23 was further characterized by tandem affinity purification. Immunoprecipitation, subfractionation and immunolocalization studies in combination with RNAi were used to validate the Keratin 23-14-3-3ε interaction. We identified keratins 8 and 18, heat shock proteins 60 and 70, plectin 1, as well as 14-3-3ε and γ as novel proteins present in the KRT23-interacting complex. Co-immunoprecipitation and subfractionation analyses as well as immunolocalization studies in our Smad4-SW480 model cells provided further evidence that KRT23 associates with 14-3-3ε and that Smad4 dependent KRT23 up-regulation induces a shift of the 14-3-3ε protein from a nuclear to a cytoplasmic localization. Based on our findings we propose a new regulatory circuitry involving Smad4 dependent up-regulation of KRT23 (directly or indirectly) which in turn modulates the interaction between KRT23 and 14-3-3ε leading to a cytoplasmic sequestration of 14-3-3ε. This cytoplasmic KRT23-14-3-3 interaction may alter the functional status of the well described 14-3-3 scaffold protein, known to regulate key cellular processes, such as signal transduction, cell cycle control, and apoptosis and may thus be a previously unappreciated facet of the Smad4 tumor suppressive circuitry

  19. Validation of a simplified carbon-14-urea breath test for routine use for detecting Helicobacter pylori noninvasively

    International Nuclear Information System (INIS)

    Henze, E.; Malfertheiner, P.; Clausen, M.; Burkhardt, H.; Adam, W.E.

    1990-01-01

    A carbon-14 ( 14 C) urea breath test for detecting Helicobacter pylori with multiple breath sampling was developed. Carbon-14-urea (110 kBq) administered orally to 18 normal subjects and to 82 patients with Helicobacter infection. The exhaled 14 C-labeled CO 2 was trapped at 10-min intervals for 90 min. The total 14 C activity exhaled over 90 min was integrated and expressed in %activity of the total dose given. In normals, a mean of 0.59% +/- 0.24% was measured, resulting in an upper limit of normal of 1.07%. In 82 patients, a sensitivity of 90.2%, a specificity of 83.8%, and a positive predictive value of 90.2% was found. The single probes at intervals of 40-60 min correlated best with the integrated result, with r ranging from 0.986 to 0.990. The test's diagnostic accuracy did not change at all when reevaluated with the 40-, 50-, or 60-min sample data alone. Thus, the 14 C-urea breath test can be applied routinely as a noninvasive, low-cost and one-sample test with high diagnostic accuracy in detecting Helicobacter pylori colonization

  20. Evaluation of carbon-14 (C14) levels of terrestrial and marine food products of the environment of the site of Cogema La Hague

    International Nuclear Information System (INIS)

    2006-04-01

    This evaluation has for object to inform about the levels in carbon 14 in the environment of the factories of La Hague. Two sectors were differentiated on one hand the terrestrial environment, and on the other hand the marine environment. The investigations concerned first and foremost food products stemming as the vegetable culture (vegetables) or individual breeding (milk, eggs) but also foodstuffs stemming from the local agriculture (cereal). In touch with the second sector, the marine environment, the sampling concerned the accessible products of the sea by all and those locally marketed (fishes, molluscs, shellfishes). The different results are presented in tables. (N.C.)

  1. Response of a carbon-walled proportional counter to 14 MeV neutrons

    International Nuclear Information System (INIS)

    Lewis, K.D.

    1982-01-01

    The response of a carbon-walled spherical proportional counter filled with a methane-based tissue-equivalent gas mixture at low pressure and irradiated with 14 MeV neutrons is first measured experimentally and is then calculated theoretically by using an analytical model. The model, called the CISS model, is derived from a consideration of four basic modes of interaction of charged particles generated in neutron-nucleus reactions with the spherical cavity of the detector. Since several quantities which have application in neutron dosimetry, radiation protection, and radiation biology make direct use of such spectra, it is desirable to have the ability to theoretically predict what is expected experimentally. Thus, a comparison between the two response curves is made. The discrepancy between them is investigated by considering several physical phenomena occurring within the detector wall which tend to distort the experimental response curve. In particular, the C(n,n',3α) reaction occurring in the detector wall gives rise to multiple events, originating from a single neutron interaction in the wall simultaneously strike the detector cavity, and are recorded as a single larger event in an experimental spectra. In the analytic model, the simultaneous entry of two charged particles into the cavity is scored as two separate smaller events, uncorrelated in their production. In this work, an effort is made to modify the analytic model prediction of the response curve by correcting for the multiple events which occur. Finally, the CISS model is used to compute mass stopping power corrections for this inhomogeneous detector

  2. Synthesis and solubility measurement in supercritical carbon dioxide of two solid derivatives of 2-methylnaphthalene-1,4-dione (menadione): 2-(Benzylamino)-3-methylnaphthalene-1,4-dione and 3-(phenethylamino)-2-methylnaphthalene-1,4-dione

    International Nuclear Information System (INIS)

    Zacconi, Flavia C.; Nuñez, Olga N.; Cabrera, Adolfo L.; Valenzuela, Loreto M.

    2016-01-01

    Highlights: • Two menadione derivatives were synthesized, purified and characterized. • Solubility of menadione derivatives in SC-CO 2 was measured at T < 333 K, p < 28 MPa. • Thermodynamic consistency of solubility data measured was evaluated. • Solubility data was correlated in terms of temperature and CO 2 density. - Abstract: Synthesis of two solid derivatives of vitamin K 3 (2-methylnaphthalene-1,4-dione or menadione), 2-(benzylamino)-3-methylnaphthalene-1,4-dione and 3-(phenethylamino)-2-methylnaphthalene-1,4-dione was completed using a 1,4 Michael addition reaction at 323 K in an inert atmosphere, with reaction yields of 62% mol·mol −1 and 71% mol·mol −1 , respectively, and a purity grade of 98% mol·mol −1 for each component. Isothermal solubility (mole fraction) of each solid derivative in supercritical carbon dioxide was performed using an analytic-recirculation methodology, with direct determination of the molar composition of the carbon dioxide-rich phase by using high performance liquid chromatography, at temperatures of (313, 323 and 333) K and pressures from (8–28) MPa. Results indicated that the range of measured solubilities were from (59 × 10 −6 to 368 × 10 −6 ) mol·mol −1 for solid 2-(benzylamino)-3-methylnaphthalene-1,4-dione and from (40 × 10 −6 to 205 × 10 −6 ) mol·mol −1 for solid 3-(phenethylamino)-2-methylnaphthalene-1,4-dione. The experimental solubility was validated using three approaches, estimating the combined expanded uncertainty of measurement for each solubility data point, evaluating the thermodynamic consistency of the data utilizing a test based on the Gibbs–Duhem equation, and verifying the self-consistency by correlating the experimental solubility values with a semi-empirical model as a function of temperature, pressure and pure carbon dioxide density.

  3. Cross sections for the production of Li and Be isotopes in carbon targets irradiated by 300 GeV protons

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Lestringuez, J.; Yiou, F.

    1975-01-01

    Cross sections for the production of Li and Be isotopes in carbon targets irradiated by 300 GeV protons were measured by mass spectrometry. The results are compared with lower energy measurements and discussed in terms of the variation of the cosmic ray L/M ratio in this energy region [fr

  4. Cross sections for the production of Li and Be isotopes in carbon targets irradiated by 300 GeV protons

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Lestringuez, J.; Yiou, F.

    1975-01-01

    Cross sections for the production of Li and Be isotopes in carbon targets irradiated by 300 GeV protons have been measured by mass spectrometry. The results are compared with lower energy measurements and discussed in terms of the variation of the cosmic ray L/M ratio in the energy region [fr

  5. Coprecipitation of {sup 14}C and Sr with carbonate precipitates: The importance of reaction kinetics and recrystallization pathways

    Energy Technology Data Exchange (ETDEWEB)

    Hodkin, David J. [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Stewart, Douglas I. [School of Civil Engineering, University of Leeds (United Kingdom); Graham, James T. [National Nuclear Laboratory, Sellafield, Cumbria (United Kingdom); Burke, Ian T., E-mail: I.T.Burke@leeds.ac.uk [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2016-08-15

    This study investigated the simultaneous removal of Sr{sup 2+} and {sup 14}CO{sub 3}{sup 2−} from pH > 12 Ca(OH){sub 2} solution by the precipitation of calcium carbonate. Initial Ca{sup 2+}:CO{sub 3}{sup 2−} ratios ranged from 10:1 to 10:100 (mM:mM). Maximum removal of {sup 14}C and Sr{sup 2+} both occurred in the system containing 10 mM Ca{sup 2+} and 1 mM CO{sub 3}{sup 2−} (99.7% and 98.6% removal respectively). A kinetic model is provided that describes {sup 14}C and Sr removal in terms of mineral dissolution and precipitation reactions. The removal of {sup 14}C was achieved during the depletion of the initial TIC in solution, and was subsequently significantly affected by recrystallization of the calcite precipitate from an elongate to isotropic morphology. This liberated > 46% of the {sup 14}C back to solution. Sr{sup 2+} removal occurred as Ca{sup 2+} became depleted in solution and was not significantly affected by the recrystallization process. The proposed reaction could form the basis for low cost remediation scheme for {sup 90}Sr and {sup 14}C in radioactively contaminated waters (<$0.25 reagent cost per m{sup 3} treated). - Highlights: • 99.7% of {sup 14}C and 98.6% of Sr removed from aqueous solution by CaCO{sub 3} precipitation. • Remobilization of {sup 14}C observed during calcium carbonate recrystallization. • Sr displayed variable distribution coefficient (possibly affected by Ca:Sr ratio). • Reagent cost of $0.22/m{sup 3} of treated groundwater.

  6. The present status of carbon 14 analysis and projects for beryllium 10 analysis at the Tandetron 1 accelerator, Nagoya University

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshio; Oda, Hirotaka; Ikeda, Akiko; Niu, Etsuko [Nagoya Univ. (Japan)

    2001-02-01

    The operation experience in 1999 of the Tandetron accelerator age estimation system, Nagoya University, is reported, after the overview and the history of the accelerator is briefly described. Total number of carbon 14 environmental samples analyzed was 8567. The project of introducing new HVEE Tandetron for C-14 analysis, and modifying the present GIC Tandetron for Be-10 analysis is presented. Ion source shall be replaced, and the heavy ion detector shall be installed. Projected geological and archaeological studies using Be-10 are enumerated. (A. Yamamoto)

  7. Validation of ten-minute single sample carbon-14 urea breath test for diagnosis of Helicobacter pylori infection

    International Nuclear Information System (INIS)

    Prabakaran, K.; Fernandes, V.; McDonald, J.

    1996-01-01

    Helicobacter pylori infection is traditionally diagnosed by endoscopy followed by gastric biopsy and histologic demonstration of organisms, rapid urease test and culture. The non-invasive carbon-14-urea breath test has been widely accepted now for the diagnosis of this bacterium. This study was aimed to establish and validate normal and abnormal values for an Australian population, for a single sample carbon-14-urea breath test at ten minutes. A dose of 185 kBq was used in order to achieve reasonable counting statistics. The derived values were validated with the results of the rapid urease test. This method has a high sensitivity, specificity and greater patient acceptance, and could be used in many clinical settings as the first modality for the diagnosis of H. pylori infection and for documenting response or cure after antibiotic therapy for eradication. 11 refs., 1 tab., 4 figs

  8. The use of C-14 as tracer in the carbon flow assimilated by the plants (maize, sugar cane, bean)

    International Nuclear Information System (INIS)

    Paula Eduardo, B. de; Cerri, C.C.

    1988-01-01

    The flow of carbon in three different crops (maize, beans and sugar cane) was studied by use of C-14. The plants were exposed to an atmosphere with a constant concentration of the tracer for 12 hours in a biosynthesis chamber. The detection of the isotope permitted the distribution and concentration of the photosynthetates in the various organs of the plants to be followed. (M.A.C.) [pt

  9. Radiocarbon (14C) Constraints On The Fraction Of Refractory Dissolved Organic Carbon In Primary Marine Aerosol From The Northwest Atlantic

    Science.gov (United States)

    Beaupre, S. R.; Kieber, D. J.; Keene, W. C.; Long, M. S.; Frossard, A. A.; Kinsey, J. D.; Duplessis, P.; Chang, R.; Maben, J. R.; Lu, X.; Zhu, Y.; Bisgrove, J.

    2017-12-01

    Nearly all organic carbon in seawater is dissolved (DOC), with more than 95% considered refractory based on modeled average lifetimes ( 16,000 years) and characteristically old bulk radiocarbon (14C) ages (4000 - 6000 years) that exceed the timescales of overturning circulation. Although this refractory dissolved organic carbon (RDOC) is present throughout the oceans as a major reservoir of the global carbon cycle, its sources and sinks are poorly constrained. Recently, RDOC was proposed to be removed from the oceans through adsorption onto the surfaces of rising bubble plumes produced by breaking waves, ejection into the atmosphere via bubble bursting as a component of primary marine aerosol (PMA), and subsequent oxidation in the atmosphere. To test this mechanism, we used natural abundance 14C (5730 ± 40 yr half-life) to trace the fraction of RDOC in PMA produced in a high capacity generator at two biologically-productive and two oligotrophic hydrographic stations in the Northwest Atlantic Ocean during a research cruise aboard the R/V Endeavor (Sep - Oct 2016). The 14C signatures of PMA separately generated day and night from near-surface (5 m) and deep (2500 m) seawater were compared with corresponding 14C signatures in seawater of near-surface dissolved inorganic carbon (DIC, a proxy for recently produced organic matter), bulk deep DOC (a proxy for RDOC), and near-surface bulk DOC. Results constrain the selectivity of PMA formation from RDOC in natural mixtures of recently produced and refractory DOC. The implications of these results for PMA formation and RDOC biogeochemistry will be discussed.

  10. Spherical cauliflower-like carbon dust formed by interaction between deuterium plasma and graphite target and its internal structure

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, N. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)], E-mail: ohno@ees.nagoya-u.ac.jp; Yoshimi, M. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Tokitani, M. [National Institute for Fusion Science, Oroshi 322-6, Toki 509-5292 (Japan); Takamura, S. [Department of Electronics, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Tokunaga, K.; Yoshida, N. [Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    2009-06-15

    Simulated experiments to produce carbon dust particles with cauliflower structure have been performed in a liner plasma device, NAGDIS-II by exposing high density deuterium plasma to a graphite sample (IG-430U). Formation of carbon dust depends on the surface temperature and the incident ion energy. At a surface temperature 600-700 K, a lot of isolated spherical dust particles are observed on the graphite target. The internal structure of an isolated dust particle was observed with Focused Ion Beam (FIB) system and Transmission Electron Microscope (TEM) in detail. FIB analysis clearly shows there exist honey-combed cell structure with thin carbon walls in the dust particle and the dust particle grows from the graphite surface. TEM image also shows that the dust particle is made of amorphous carbon with crystallized grains with diameters of 10-50 nm.

  11. Targeting single-walled carbon nanotubes for the treatment of breast cancer using photothermal therapy

    Science.gov (United States)

    Neves, Luís F. F.; Krais, John J.; Van Rite, Brent D.; Ramesh, Rajagopal; Resasco, Daniel E.; Harrison, Roger G.

    2013-09-01

    This paper focuses on the targeting of single-walled carbon nanotubes (SWNTs) for the treatment of breast cancer with minimal side effects using photothermal therapy. The human protein annexin V (AV) binds specifically to anionic phospholipids expressed externally on the surface of tumour cells and endothelial cells that line the tumour vasculature. A 2 h incubation of the SWNT-AV conjugate with proliferating endothelial cells followed by washing and near-infrared (NIR) irradiation at a wavelength of 980 nm was enough to induce significant cell death; there was no significant cell death with irradiation or the conjugate alone. Administration of the same conjugate i.v. in BALB/c female mice with implanted 4T1 murine mammary at a dose of 0.8 mg SWNT kg-1 and followed one day later by NIR irradiation of the tumour at a wavelength of 980 nm led to complete disappearance of implanted 4T1 mouse mammary tumours for the majority of the animals by 11 days since the irradiation. The combination of the photothermal therapy with the immunoadjuvant cyclophosphamide resulted in increased survival. The in vivo results suggest the SWNT-AV/NIR treatment is a promising approach to treat breast cancer.

  12. Hyaluronate tethered, "smart" multiwalled carbon nanotubes for tumor-targeted delivery of doxorubicin.

    Science.gov (United States)

    Datir, Satyajit R; Das, Manasmita; Singh, Raman Preet; Jain, Sanyog

    2012-11-21

    The present study reports the optimized synthesis, physicochemical characterization, and biological evaluation of a novel, multiwalled carbon nanotube-hyaluronic acid (MWCNT-HA) conjugate, complexed with an anticancer agent, Doxorubicin (DOX) via π-π stacking interaction. The therapeutic conjugate was concomitantly labeled with a near-infrared fluorescent dye, Alexa-Flour-647 (AF-647), and radiotracer Technetium-99m ((99m)Tc) to track its whereabouts both in vitro and in vivo via optical and scintigraphic imaging techniques. Covalent functionalization of MWCNTs with HA facilitated their internalization into human lung adenocarcinoma, A549 cells via hyaluronan receptors (HR) mediated endocytosis. Internalized nanotubes showed lysosomal trafficking, followed by low pH-triggered DOX release under endolysosomal conditions. Consequently, DOX-loaded HA-MWCNTs exhibited 3.2 times higher cytotoxicity and increased apoptotic activity than free DOX in equivalent concentrations. Organ distribution studies in Ehlrich ascites tumor (EAT) bearing mice model indicated that tumor specific localization of (99m)Tc-MWCNT-HA-DOX is significantly higher than both free drug and nontargeted MWCNTs. Pharmacodynamic studies in chemically breast-cancer-induced rats showed that the tumor-growth inhibitory effect of HA-MWCNT-DOX was 5 times higher than free DOX in equivalent concentration. DOX delivered through HA-MWCNTs was devoid of any detectable cardiotoxity, hepatotoxicity, or nephrotoxicity. All these promising attributes make HA-MWCNTs a "smart" platform for tumor-targeted delivery of anticancer agents.

  13. Giant Negative Piezoresistive Effect in Diamond-like Carbon and Diamond-like Carbon-Based Nickel Nanocomposite Films Deposited by Reactive Magnetron Sputtering of Ni Target

    DEFF Research Database (Denmark)

    Meškinis, Šaru Nas; Gudaitis, Rimantas; Šlapikas, Kęstutis

    2018-01-01

    deposited by either reactive HIPIMS or dc magnetron sputtering of Ni target was explained by possible clustering of the sp2-bonded carbon and/or formation of areas with the decreased hydrogen content. It was suggested that the tensile stress-induced rearrangements of these conglomerations have resulted......Piezoresistive properties of hydrogenated diamond-like carbon (DLC) and DLC-based nickel nanocomposite (DLC:Ni) films were studied in the range of low concentration of nickel nanoparticles. The films were deposited by reactive high power pulsed magnetron sputtering (HIPIMS) of Ni target, and some...... samples were deposited by direct current (dc) reactive magnetron sputtering for comparison purposes. Raman scattering spectroscopy, energy-dispersive X-ray spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS) were used to study the structure and chemical composition of the films. A four...

  14. Margin estimation and disturbances of irradiation field in layer-stacking carbon-ion beams for respiratory moving targets.

    Science.gov (United States)

    Tajiri, Shinya; Tashiro, Mutsumi; Mizukami, Tomohiro; Tsukishima, Chihiro; Torikoshi, Masami; Kanai, Tatsuaki

    2017-11-01

    Carbon-ion therapy by layer-stacking irradiation for static targets has been practised in clinical treatments. In order to apply this technique to a moving target, disturbances of carbon-ion dose distributions due to respiratory motion have been studied based on the measurement using a respiratory motion phantom, and the margin estimation given by the square root of the summation Internal margin2+Setup margin2 has been assessed. We assessed the volume in which the variation in the ratio of the dose for a target moving due to respiration relative to the dose for a static target was within 5%. The margins were insufficient for use with layer-stacking irradiation of a moving target, and an additional margin was required. The lateral movement of a target converts to the range variation, as the thickness of the range compensator changes with the movement of the target. Although the additional margin changes according to the shape of the ridge filter, dose uniformity of 5% can be achieved for a spherical target 93 mm in diameter when the upward range variation is limited to 5 mm and the additional margin of 2.5 mm is applied in case of our ridge filter. Dose uniformity in a clinical target largely depends on the shape of the mini-peak as well as on the bolus shape. We have shown the relationship between range variation and dose uniformity. In actual therapy, the upper limit of target movement should be considered by assessing the bolus shape. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  15. Volatile elements production rates in a 1.4 Gev proton-irradiated molten lead-bismuth target

    CERN Document Server

    Zanini, L; Everaerts, P; Fallot, M; Franberg, H; Gröschel, F; Jost, C; Kirchner, T; Kojima, Y; Köster, U; Lebenhaft, J; Manfrina, E; Pitcher, E J; Ravn, H L; Tall, Y; Wagner, W; Wohlmuther, M

    2005-01-01

    Production rates of volatile elements following spallation reaction of 1.4 GeV protons on a liquid Pb/Bi target have been measured. The experiment was performed at the ISOLDE facility at CERN. These data are of interest for the developments of targets for accelerator driven systems such as MEGAPIE. Additional data have been taken on a liquid Pb target. Calculations were performed using the FLUKA and MCNPX Monte Carlo codes coupled with the evolution codes ORIHET3 and FISPACT using different options for the intra-nuclear cascades and evaporation models. Preliminary results from the data analysis show good comparison with calculations for Hg and for noble gases. For other elements such as I it is apparent that only a fraction of the produced isotopes is released. The agreement with the experimental data varies depending on the model combination used. The best results are obtained using MCNPX with the INCL4/ABLA models and with FLUKA. Discrepancies are found for some isotopes produced by fission using the MCNPX ...

  16. Targeting carbonic anhydrase IX by nitroimidazole based sulfamides enhances the therapeutic effect of tumor irradiation: A new concept of dual targeting drugs

    International Nuclear Information System (INIS)

    Dubois, Ludwig; Peeters, Sarah G.J.A.; Kuijk, Simon J.A. van; Yaromina, Ala; Lieuwes, Natasja G.; Saraya, Ruchi; Biemans, Rianne; Rami, Marouan; Parvathaneni, Nanda Kumar; Vullo, Daniela; Vooijs, Marc; Supuran, Claudiu T.; Winum, Jean-Yves

    2013-01-01

    Background and purpose: Carbonic anhydrase IX (CAIX) plays an important role in pH regulation processes critical for tumor cell growth and metastasis. We hypothesize that a dual targeting bioreductive nitroimidazole based anti-CAIX sulfamide drug (DH348) will reduce tumor growth and sensitize tumors to irradiation in a CAIX dependent manner. Material and methods: The effect of the dual targeting anti-CAIX (DH348) and its single targeting control drugs on extracellular acidification and radiosensitivity was examined in HT-29 colorectal carcinoma cells. Tumor growth and time to reach 4× start volume (T4×SV) was monitored for animals receiving DH348 (10 mg/kg) combined with tumor single dose irradiation (10 Gy). Results: In vitro, DH348 reduced hypoxia-induced extracellular acidosis, but did not change hypoxic radiosensitivity. In vivo, DH348 monotherapy decreased tumor growth rate and sensitized tumors to radiation (enhancement ratio 1.50) without systemic toxicity only for CAIX expressing tumors. Conclusions: A newly designed nitroimidazole and sulfamide dual targeting drug reduces hypoxic extracellular acidification, slows down tumor growth at nontoxic doses and sensitizes tumors to irradiation all in a CAIX dependent manner, suggesting no “off-target” effects. Our data therefore indicate the potential utility of a dual drug approach as a new strategy for tumor-specific targeting

  17. A survey of methods to immobilize tritium and carbon-14 arising from a nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Taylor, P.

    1991-02-01

    This report reviews the literature on methods to separate and immobilize tritium ( 3 H) and carbon-14 ( 14 C) released from U0 2 fuel in a nuclear fuel reprocessing plant. It was prepared as part of a broader review of fuel reprocessing waste management methods that might find future application in Canada. The calculated inventories of both 3 H and 14 C in used fuel are low; special measures to limit releases of these radionuclides from reprocessing plants are not currently in place, and may not be necessary in future. If required, however, several possible approaches to the concentration and immobilization of both radionuclides are available for development. Technology to control these radionuclides in reactor process streams is in general more highly developed than for reprocessing plant effluent, and some control methods may be adaptable to reprocessing applications

  18. Cambrian-lower Middle Ordovician passive carbonate margin, southern Appalachians: Chapter 14

    Science.gov (United States)

    Read, J. Fred; Repetski, John E.

    2012-01-01

    The southern Appalachian part of the Cambrian–Ordovician passive margin succession of the great American carbonate bank extends from the Lower Cambrian to the lower Middle Ordovician, is as much as 3.5 km (2.2 mi) thick, and has long-term subsidence rates exceeding 5 cm (2 in.)/k.y. Subsiding depocenters separated by arches controlled sediment thickness. The succession consists of five supersequences, each of which contains several third-order sequences, and numerous meter-scale parasequences. Siliciclastic-prone supersequence 1 (Lower Cambrian Chilhowee Group fluvial rift clastics grading up into shelf siliciclastics) underlies the passive margin carbonates. Supersequence 2 consists of the Lower Cambrian Shady Dolomite–Rome-Waynesboro Formations. This is a shallowing-upward ramp succession of thinly bedded to nodular lime mudstones up into carbonate mud-mound facies, overlain by lowstand quartzose carbonates, and then a rimmed shelf succession capped by highly cyclic regressive carbonates and red beds (Rome-Waynesboro Formations). Foreslope facies include megabreccias, grainstone, and thin-bedded carbonate turbidites and deep-water rhythmites. Supersequence 3 rests on a major unconformity and consists of a Middle Cambrian differentiated rimmed shelf carbonate with highly cyclic facies (Elbrook Formation) extending in from the rim and passing via an oolitic ramp into a large structurally controlled intrashelf basin (Conasauga Shale). Filling of the intrashelf basin caused widespread deposition of thin quartz sandstones at the base of supersequence 4, overlain by widespread cyclic carbonates (Upper Cambrian lower Knox Group Copper Ridge Dolomite in the south; Conococheague Formation in the north). Supersequence 5 (Lower Ordovician upper Knox in the south; Lower to Middle Ordovician Beekmantown Group in the north) has a basal quartz sandstone-prone unit, overlain by cyclic ramp carbonates, that grade downdip into thrombolite grainstone and then storm

  19. Carbon-14 activity of fallout in Araucaria angustifolia annual growth rings, from Arapoti, Parana State, Brazil

    International Nuclear Information System (INIS)

    Lisi, Claudio Sergio; Pessenda, Luiz Carlos Ruiz; Tomazello Filho, Mario

    2000-01-01

    During the period of nuclear tests between 1950 and 1960, an input of artificial 14 C (fallout effect) occurred in the natural reservoirs. 14 C determinations in the Northern Hemisphere showed values of Δ 14 C up to 960 in the year of 1964. To determine the fallout 14 C activity in Brazil, wood samples from Araucaria angustifolia (Bert.) O. Kuntze, Araucariaceae, were collected in Arapoti-PR (24 deg 11 S , 49 deg 58 O ). The annual tree rings were selected by dendrochronology. The cellulose was extracted and its 14 C activity determined by liquid scintillation method. The results showed a significant increase of the Δ 14 C up to 590 in 1965, about 60% higher than the natural activity, gradually decreasing after the end of nuclear tests. These results were correlated with those obtained in the Northen Hemisphere and will be used in the studies of CO 2 mechanisms distribuition to the atmosphere and other natural reservoirs. (author)

  20. Can we bet on negative emissions to achieve the 2°C target even under strong carbon cycle feedbacks?

    Science.gov (United States)

    Tanaka, K.; Yamagata, Y.; Yokohata, T.; Emori, S.; Hanaoka, T.

    2015-12-01

    Negative emission technologies such as Bioenergy with Carbon dioxide Capture and Storage (BioCCS) play an ever more crucial role in meeting the 2°C stabilization target. However, such technologies are currently at their infancy and their future penetrations may fall short of the scale required to stabilize the warming. Furthermore, the overshoot in the mid-century prior to a full realization of negative emissions would give rise to a risk because such a temporal but excessive warming above 2°C might amplify itself by strengthening climate-carbon cycle feedbacks. It has not been extensively assessed yet how carbon cycle feedbacks might play out during the overshoot in the context of negative emissions. This study explores how 2°C stabilization pathways, in particular those which undergo overshoot, can be influenced by carbon cycle feedbacks and asks their climatic and economic consequences. We compute 2°C stabilization emissions scenarios under a cost-effectiveness principle, in which the total abatement costs are minimized such that the global warming is capped at 2°C. We employ a reduced-complexity model, the Aggregated Carbon Cycle, Atmospheric Chemistry, and Climate model (ACC2), which comprises a box model of the global carbon cycle, simple parameterizations of the atmospheric chemistry, and a land-ocean energy balance model. The total abatement costs are estimated from the marginal abatement cost functions for CO2, CH4, N2O, and BC.Our preliminary results show that, if carbon cycle feedbacks turn out to be stronger than what is known today, it would incur substantial abatement costs to keep up with the 2°C stabilization goal. Our results also suggest that it would be less expensive in the long run to plan for a 2°C stabilization pathway by considering strong carbon cycle feedbacks because it would cost more if we correct the emission pathway in the mid-century to adjust for unexpectedly large carbon cycle feedbacks during overshoot. Furthermore, our

  1. Carbonic anhydrase inhibitors: Design, synthesis and structural characterization of new heteroaryl-N-carbonylbenzenesulfonamides targeting druggable human carbonic anhydrase isoforms

    Czech Academy of Sciences Publication Activity Database

    Buemi, M. R.; De Luca, L.; Ferro, S.; Bruno, E.; Ceruso, M.; Supuran, C. T.; Pospíšilová, K.; Brynda, Jiří; Řezáčová, Pavlína; Gitto, R.

    2015-01-01

    Roč. 102, Sep 18 (2015), s. 223-232 ISSN 0223-5234 Institutional support: RVO:61388963 Keywords : human carbonic anhydrase * isoquinoline * quinoline * X-ray * molecular docking Subject RIV: CE - Biochemistry Impact factor: 3.902, year: 2015

  2. Large-scale Patterns of 14C Age of Bulk Organic Carbon and Various Molecular Components in Grassland Soils

    Science.gov (United States)

    Jia, J.; Liu, Z.; Cao, Z.; Chen, L.; He, J. S.; Haghipour, N.; Wacker, L.; Eglinton, T. I.; Feng, X.

    2017-12-01

    Unraveling the fate of organic carbon (OC) in soils is essential to understanding the impact of global changes on the global carbon cycle. Previous studies have shown that while various soil OC components have different decomposability, chemically labile OC can have old 14C ages. However, few studies have compared the 14C age of various soil OC components on a large scale, which may provide important information on the link between the age or turnover of soil OC components to their sources, molecular structures as well as environmental variables. In this project, a suite of soil profiles were sampled along a large-scale transect of temperate and alpine grasslands across the Tibetan and Mongolian Plateaus in China with contrasting climatic, vegetation and soil properties. Bulk OC and source-specific compounds (including fatty acids (FAs), diacids (DAs) and lignin phenols) were radiocarbon-dated to investigate the age and turnover dynamics of different OC pools and the mechanisms controlling their stability. Our results show that lignin phenols displayed a large 14C variability. Short-chain (C16, 18) FAs sourced from vascular plants as well as microorganisms were younger than plant-derived long-chain FAs and DAs, indicating that short-chain FAs were easier to be decomposed or newly synthesized. In the temperate grasslands, long-chain DAs were younger than FAs, while the opposite trend was observed in the alpine grasslands. Preliminary correlation analysis suggests that the age of short-chain FAs were mainly influenced by clay contents and climate, while reactive minerals, clay or silt particles were important factors in the stabilization of long-chain FAs, DAs and lignin phenols. Overall, our study provided a unique 14 C dataset of soil OC components in grasslands, which will provide important constraints on soil carbon turnover in future investigations.

  3. Phosphatidylserine targeted single-walled carbon nanotubes for photothermal ablation of bladder cancer

    Science.gov (United States)

    Virani, Needa A.; Davis, Carole; McKernan, Patrick; Hauser, Paul; Hurst, Robert E.; Slaton, Joel; Silvy, Ricardo P.; Resasco, Daniel E.; Harrison, Roger G.

    2018-01-01

    Bladder cancer has a 60%-70% recurrence rate most likely due to any residual tumour left behind after a transurethral resection (TUR). Failure to completely resect the cancer can lead to recurrence and progression into higher grade tumours with metastatic potential. We present here a novel therapy to treat superficial tumours with the potential to decrease recurrence. The therapy is a heat-based approach in which bladder tumour specific single-walled carbon nanotubes (SWCNTs) are delivered intravesically at a very low dose (0.1 mg SWCNT per kg body weight) followed 24 h later by a short 30 s treatment with a 360° near-infrared light that heats only the bound nanotubes. The energy density of the treatment was 50 J cm-2, and the power density that this treatment corresponds to is 1.7 W cm-2, which is relatively low. Nanotubes are specifically targeted to the tumour via the interaction of annexin V (AV) and phosphatidylserine, which is normally internalised on healthy tissue but externalised on tumours and the tumour vasculature. SWCNTs are conjugated to AV, which binds specifically to bladder cancer cells as confirmed in vitro and in vivo. Due to this specific localisation, NIR light can be used to heat the tumour while conserving the healthy bladder wall. In a short-term efficacy study in mice with orthotopic MB49 murine bladder tumours treated with the SWCNT-AV conjugate and NIR light, no tumours were visible on the bladder wall 24 h after NIR light treatment, and there was no damage to the bladder. In a separate survival study in mice with the same type of orthotopic tumours, there was a 50% cure rate at 116 days when the study was ended. At 116 days, no treatment toxicity was observed, and no nanotubes were detected in the clearance organs or bladder.

  4. Path towards achieving of China's 2020 carbon emission reduction target-A discussion of low-carbon energy policies at province level

    International Nuclear Information System (INIS)

    Wang Run; Liu Wenjuan; Xiao Lishan; Liu Jian; Kao, William

    2011-01-01

    Following the announcement of the China's 2020 national target for the reduction of the intensity of carbon dioxide emissions per unit of GDP by 40-45% compared with 2005 levels, Chinese provincial governments prepared to restructure provincial energy policy and plan their contribution to realizing the State reduction target. Focusing on Fujian and Anhui provinces as case studies, this paper reviews two contrasting policies as a means for meeting the national reduction target. That of the coastal province of Fujian proposes to do so largely through the development of nuclear power, whilst the coal-rich province of Anhui proposes to do so through its energy consumption rate rising at a lower rate than that of the rise in GDP. In both cases renewable energy makes up a small proportion of their proposed 2020 energy structures. The conclusion discusses in depth concerns about nuclear power policy, energy efficiency, energy consumption strategy and problems in developing renewable energy. - Research Highlights: → We review two contrasting policies as a means for meeting the national reduction target of carbon emission in two provinces. → Scenario review of energy structure in Fujian and Anhui Provinces to 2020. → We discuss concerns about nuclear power policy, energy efficiency, energy consumption strategy and problems in developing renewable energy.

  5. Abiotic and bioaugmented granular activated carbon for the treatment of 1,4-dioxane-contaminated water.

    Science.gov (United States)

    Myers, Michelle A; Johnson, Nicholas W; Marin, Erick Zerecero; Pornwongthong, Peerapong; Liu, Yun; Gedalanga, Phillip B; Mahendra, Shaily

    2018-06-04

    1,4-Dioxane is a probable human carcinogen and an emerging contaminant that has been detected in surface water and groundwater resources. Many conventional water treatment technologies are not effective for the removal of 1,4-dioxane due to its high water solubility and chemical stability. Biological degradation is a potentially low-cost, energy-efficient approach to treat 1,4-dioxane-contaminated waters. Two bacterial strains, Pseudonocardia dioxanivorans CB1190 (CB1190) and Mycobacterium austroafricanum JOB5 (JOB5), have been previously demonstrated to break down 1,4-dioxane through metabolic and co-metabolic pathways, respectively. However, both CB1190 and JOB5 have been primarily studied in laboratory planktonic cultures, while most environmental microbes grow in biofilms on surfaces. Another treatment technology, adsorption, has not historically been considered an effective means of removing 1,4-dioxane due to the contaminant's low K oc and K ow values. We report that the granular activated carbon (GAC), Norit 1240, is an adsorbent with high affinity for 1,4-dioxane as well as physical dimensions conducive to attached bacterial growth. In abiotic batch reactor studies, 1,4-dioxane adsorption was reversible to a large extent. By bioaugmenting GAC with 1,4-dioxane-degrading microbes, the adsorption reversibility was minimized while achieving greater 1,4-dioxane removal when compared with abiotic GAC (95-98% reduction of initial 1,4-dioxane as compared to an 85-89% reduction of initial 1,4-dioxane, respectively). Bacterial attachment and viability was visualized using fluorescence microscopy and confirmed by amplification of taxonomic genes by quantitative polymerase chain reaction (qPCR) and an ATP assay. Filtered samples of industrial wastewater and contaminated groundwater were also tested in the bioaugmented GAC reactors. Both CB1190 and JOB5 demonstrated 1,4-dioxane removal greater than that of the abiotic adsorbent controls. This study suggests that

  6. Measured neutron carbon kerma factors from 14.1 MeV to 18 MeV

    International Nuclear Information System (INIS)

    Deluca, P.M.; Barschall, H.H.; McDonald, J.C.

    1985-01-01

    For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in the hydrogen abundance in these materials, the principal uncertainty is due to the kerma factors of carbon and oxygen. We have measured carbon kerma factor values of 0.183+-0.015 10 -8 cGy cm 2 and 0.210+-0.016 10 -8 cGy cm 2 at 14.1-MeV and 15-MeV neutron energy, respectively. A preliminary value of 0.297+-0.03 10 -8 cGy cm 2 has been determined at 17.9 MeV. A recent microscopic cross section measurement of the (n,n'3α) reaction in carbon at 14.1-MeV energy gives a kerma factor of 0.184+-0.019 10 -8 cGy cm 2 in agreement with the present result

  7. Measured neutron carbon kerma factors from 14.1 MeV to 18 MeV

    International Nuclear Information System (INIS)

    Deluca, P.M. Jr.; Barschall, H.H.; Haight, R.C.; McDonald, J.C.

    1984-01-01

    For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in the hydrogen abundance in these materials, the principal uncertainty is due to the kerma factors of carbon and oxygen. We have measured carbon kerma factor values of 0.183 +- 0.015 10 -8 cGy cm 2 and 0.210 +- 0.16 10 -8 cGy cm 2 at 14.1-MeV and 15-MeV neutron energy, respectively. A preliminary value of 0.297 +- 0.03 10 -8 cGy cm 2 has been determined at 17.9 MeV. A recent microscopic cross section measurement of the (n,n'3α) reaction in carbon at 14.1-MeV energy gives a kerma factor of 0.184 +- 0.019 10 8 cGy cm 2 in agreement with the present result. 9 refs., 4 figs., 2 tabs

  8. Reproducibility of measurement of the environmental carbon-14 samples prepared by the gel suspension method

    International Nuclear Information System (INIS)

    Ohura, Hirotaka; Wakabayashi, Genichiro; Nakamura, Kouji; Okai, Tomio; Matoba, Masaru; Kakiuchi, Hideki; Momoshima, Noriyuki; Kawamura, Hidehisa.

    1997-01-01

    Simple liquid scintillation counting technique for the assay of 14 C in the environment was developed. This technique was done by using gel suspension method, in which sample preparation is very simple and requires no special equipments. The reproducibility of this technique was considered and it was shown that the gel suspension method had enough reproducibility to monitor the environmental 14 C. (author)

  9. Relationship between carbon-14 concentrations in tree-ring cellulose and atmospheric CO2

    International Nuclear Information System (INIS)

    Yamada, Yoshimune; Yasuike, Kaeko; Komura, Kazuhisa

    2008-01-01

    Concentrations of organically-bound 14 C in the tree-ring cellulose of a Japanese Cedar (Cryptomeria japonica) grown in a rural region of Kanazawa, Ishikawa prefecture, Japan (36.5degN, 136.7degE), were measured for the ring-years from 1989 to 1998 to study relationship between 14 C concentrations in tree-ring cellulose and atmospheric CO 2 in a narrow region. An interesting result in comparing our data of tree-ring cellulose with those of atmospheric CO 2 is that the 14 C concentration in tree-ring cellulose was close to the corresponding average from mid-June to early September of 14 C concentrations in atmospheric CO 2 . Furthermore, the 14 C concentrations in tree-ring cellulose were found to be merely influenced by the drastic decrease of 14 C concentrations in atmospheric CO 2 in winter, which might be caused by air pollution from the Asian continent and additional local fossil fuel contribution. These results suggest that the 14 C concentration in tree-ring cellulose for a given growing year reflects the 14 C concentrations of atmospheric CO 2 during the warm summer months. (author)

  10. Radiobiological half-lives for carbon-14 and hydrogen-3 leucine in man

    International Nuclear Information System (INIS)

    Classic, K.L.; Schwenk, W.F.; Haymond, M.W.

    1986-01-01

    In vivo estimates of protein metabolism in many are often made by oral or intravenous administration of leucine or its ∼-ketoacid, ∼-ketoisocaproate, labeled with 14 C or 3 H. Previous estimates of radiation dose from such tracers have been based on the measurement of 14 CO 2 in breath. Using measurements of the decay of 3 H or 14 C leucine from plasma proteins, longer biological half-lives for these compounds were obtained. The estimated total-body radiation absorbed dose is 0.97 mrad/uCi for [1- 14 C]KIC (or [1- 14 C]leucine) and 0.11 mrad/ + Ci for ]4,5- 3 H]leucine (or [ 3 H]KIC). Assuming administered doses of 100 μCi each, the total-body radiation absorbed dose is still well within the limits set by the FDA for Radioactive Drug Research Committees. 12 references, 3 figures, 3 tables

  11. Spatial analysis of Carbon-14 dynamics in a wetland ecosystem (Duke Swamp, Chalk River Laboratories, Canada)

    International Nuclear Information System (INIS)

    Yankovich, T.L.; King-Sharp, K.J.; Carr, J.; Robertson, E.; Killey, R.W.D.; Beresford, N.A.; Wood, M.D.

    2014-01-01

    A detailed survey was conducted to quantify the spatial distribution of 14 C in Sphagnum moss and underlying soil collected in Duke Swamp. This wetland environment receives 14 C via groundwater pathways from a historic radioactive Waste Management Area (WMA) on Atomic Energy Canada Limited (AECL)'s Chalk River Laboratories (CRL) site. Trends in 14 C specific activities were evaluated with distance from the sampling location with the maximum 14 C specific activity (DSS-35), which was situated adjacent to the WMA and close to an area of groundwater discharge. Based on a spatial evaluation of the data, an east-to-west 14 C gradient was found, due to the influence of the WMA on 14 C specific activities in the swamp. In addition, it was possible to identify two groups of sites, each showing significant exponential declines with distance from the groundwater source area. One of the groups showed relatively more elevated 14 C specific activities at a given distance from source, likely due to their proximity to the WMA, the location of the sub-surface plume originating from the WMA, the presence of marsh and swamp habitat types, which facilitated 14 C transport to the atmosphere, and possibly, 14 C air dispersion patterns along the eastern edge of the swamp. The other group, which had lower 14 C specific activities at a given distance from the groundwater source area, included locations that were more distant from the WMA and the sub-surface plume, and contained fen habitat, which is known to act as barrier to groundwater flow. The findings suggest that proximity to source, groundwater flow patterns and habitat physical characteristics can play an important role in the dynamics of 14 C being carried by discharging groundwater into terrestrial and wetland environments. - Highlights: • Groundwater represents an important source of volatile radionuclides to wetlands. • Habitat type influenced 14 C transport from sub-surface to surface environments. • C-14 specific

  12. Carbonic anhydrase inhibitors: Design, synthesis and structural characterization of new heteroaryl-N-carbonylbenzenesulfonamides targeting druggable human carbonic anhydrase isoforms

    Czech Academy of Sciences Publication Activity Database

    Buemi, M. R.; De Luca, L.; Ferro, S.; Bruno, E.; Ceruso, M.; Supuran, C. T.; Pospíšilová, K.; Brynda, Jiří; Řezáčová, Pavlína; Gitto, R.

    2015-01-01

    Roč. 102, SEP 18 (2015), s. 223-232 ISSN 0223-5234 R&D Projects: GA ČR GA15-05677S Grant - others:Fondo di Ateneo per la Ricerca (PRA)(IT) ORME09SPNC Institutional support: RVO:68378050 Keywords : Human carbonic anhydrase * Isoquinoline * Quinoline * X-ray * Molecular docking Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.902, year: 2015

  13. Moab, Utah: Using Energy Data to Target Carbon Reductions from Building Energy Efficiency (City Energy: From Data to Decisions)

    Energy Technology Data Exchange (ETDEWEB)

    Strategic Priorities and Impact Analysis Team, Office of Strategic Programs

    2017-11-01

    This fact sheet "Moab, Utah: Using Energy Data to Target Carbon Reductions from Building Energy Efficiency" explains how the City of Moab used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

  14. Temperature dependence of desoxyribosylation of pyrimidine derivatives labelled with carbon-14 and tritium

    International Nuclear Information System (INIS)

    Pritasil, L.; Filip, J.

    1977-01-01

    The effect of the temperature and concentration of the enzyme preparation from Escherichia coli B on the reaction of pyrimidine bases with 2-desoxy-α-D-riboso-l-phosphate or α-D-riboso-l-phosphate was studied. It was found that at +2 deg C and low enzyme concentration higher yields of nucleosides are obtained than at the commonly used temperature of 37 deg C. The reaction time, however, must be protracted. The prepared [2- 14 C] uridine, 2'-deoxy[2- 14 C] uridine and [2- 14 C] thymidine had a high specific activity and radiochemical purity

  15. Acylation of lithiated trimethylsilyl malonates and esters applied to the synthesis of molecules of biological interest, labelled with carbon 14

    International Nuclear Information System (INIS)

    Gorichon, Liliane

    1978-01-01

    This research thesis first reports an attempt to generalise the method of acylation of lithiated trimethylsilyl (TMS) malonates by introduction of new organic functions into the radical. This leads to the synthesis of some alkaloids such as nicotine and contine. The author also shows that fat acids can be labelled with carbon 14 in any position of the carbon chain. Thus, acylation of these malonates have been performed by using different acid chlorides. Then, the author reports attempts to simplify this method by using α-lithiated trimethylsilyl esters instead of malonates. He reports attempts of acylation of TMS isobutyrate, TMS proprionate and TMS acetate, by using different radioactive acid chlorides (benzoyl chloride, nicotinoyl chloride, lauryl chloride, and oleyl chloride). The author finally shows that both methods are equivalent by synthesising muscalure from TMS butylmalonate as well as from TMS hexanoate

  16. Quantification of Helicobacter pylori infection in gastritis and ulcer disease using a simple and rapid carbon-14-urea breath test

    International Nuclear Information System (INIS)

    Debongnie, J.C.; Pauwels, S.; Raat, A.; de Meeus, Y.; Haot, J.; Mainguet, P.

    1991-01-01

    Gastric urease was studied isotopically in 230 patients with biopsy-proven normal mucosa or chronic gastritis, including 59 patients with ulcer disease. Carbon-14-urea was given in 25 ml of water without substrate carrier or nutrient-dense meal, and breath samples were collected over a 60-min period. The amount of 14CO2 excreted at 10 min was independent of the rate of gastric emptying and was not quantitatively influenced by the buccal urease activity. The 10-min 14CO2 values discriminated well between Helicobacter pylori positive and negative patients (94% sensitivity, 89% specificity) and correlated with the number of organisms assessed by histology. The test was a good predictor of chronic gastritis (95% sensitivity and 96% specificity), and a quantitative relationship was observed between 14CO2 values and the severity and activity of the gastritis. In H. pylori positive patients, breath 14CO2 was found to be similar in patients with and without ulcer disease, suggesting that the number of bacteria is not a determining factor for the onset of ulceration

  17. Quantification of Helicobacter pylori infection in gastritis and ulcer disease using a simple and rapid carbon-14-urea breath test

    Energy Technology Data Exchange (ETDEWEB)

    Debongnie, J.C.; Pauwels, S.; Raat, A.; de Meeus, Y.; Haot, J.; Mainguet, P. (Department of Nuclear Medicine, University of Louvain Medical School, Brussels (Belgium))

    1991-06-01

    Gastric urease was studied isotopically in 230 patients with biopsy-proven normal mucosa or chronic gastritis, including 59 patients with ulcer disease. Carbon-14-urea was given in 25 ml of water without substrate carrier or nutrient-dense meal, and breath samples were collected over a 60-min period. The amount of 14CO2 excreted at 10 min was independent of the rate of gastric emptying and was not quantitatively influenced by the buccal urease activity. The 10-min 14CO2 values discriminated well between Helicobacter pylori positive and negative patients (94% sensitivity, 89% specificity) and correlated with the number of organisms assessed by histology. The test was a good predictor of chronic gastritis (95% sensitivity and 96% specificity), and a quantitative relationship was observed between 14CO2 values and the severity and activity of the gastritis. In H. pylori positive patients, breath 14CO2 was found to be similar in patients with and without ulcer disease, suggesting that the number of bacteria is not a determining factor for the onset of ulceration.

  18. Isolation of carbon 14 labelled amino acids by biosynthesis in maize plants (zea mais L.)

    International Nuclear Information System (INIS)

    Carreras, N.; Mazon, M.P.

    1983-01-01

    A method of obtaining 14 C labelled amino acids by biosynthesis in maize plants which had assimilated 14 CO 2 , has been assayed. The plants were labelled for 60 minutes with 14 CO 2 produced from Ba 14 CO 3 (specific activity of 148 KBq/μmol). An extract of the soluble compounds was obtained with 80% ethanol and the amino acids were separated from the rest of the soluble compounds by ion exchange chromatography on column of Dowex 50-X8 resin. Finally, seventeen amino acids were isolated and identified from the purified extract. The acid amino acids were separated in anionic column (Dowex 1-X8) and the neutral and basic amino acids in cationic columns (Dowex 50-X4). (author)

  19. Spatial Distribution and Dynamics of Carbon-14 in a Wetland Ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Yankovich, Tamara L. [International Atomic Energy Agency, P.O. Box 100, 1400 Vienna (Austria); Carr, James; King-Sharp, K.; Doug Killey, R.W. [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1J0 (Canada); Robertson, Erin [201 21st Street East, Saskatoon, SK S7K 0B8 (Canada); Beresford, Nicholas A. [NERC Centre for Ecology and Hydrology, Lancaster Environment Center, Bailrigg, Lancaster, LA14AP (United Kingdom); School of Environment and Life Sciences, University of Salford, Manchester, M44WT (United Kingdom); Wood, Michael D. [School of Environment and Life Sciences, University of Salford, Manchester, M44WT (United Kingdom)

    2014-07-01

    There is significant interest in assessing the impact of {sup 14}C releases from nuclear facilities, radioactive waste management areas, and geologic disposal facilities. As a result, there is a general need to gain understanding of {sup 14}C dynamics, especially in complex interface ecosystems, such as wetlands. This paper summarizes the key findings of two studies undertaken in Duke Swamp, a circa 0.1 km{sup 2} area of wetland consisting of marsh, fen and swamp habitats, on the Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories Site. The swamp receives radionuclides, such as {sup 14}C and tritium, from an up-gradient waste management area. The first study was an extensive field sampling campaign, involving collection of surface vegetation at 69 locations on a 50 m x 50 m grid, to evaluate the spatial distribution of {sup 14}C in Duke Swamp. Representative receptor plants and animals, and corresponding environmental media (including air, soil, and plant) samples were then collected, as part of a second study, at a subset of six locations with {sup 14}C specific activities that spanned the range present in Duke Swamp and also represented the different wetland habitats occurring there. The highest specific activity concentrations in surface vegetation were highly localized, representing a surface area of only about 150 m{sup 2}. The spatial distribution of {sup 14}C in the swamp seemed to be at least partly accounted for by the physical attributes of the Duke Swamp habitat. In general, it was found that specific activities of {sup 14}C in biota tissues reflected those measured in surface vegetation collected from the same sampling location. Such information provides needed insight for biosphere assessments, as well as for the development of monitoring programs that demonstrate protection of biota in areas where exposure to {sup 14}C is elevated. (authors)

  20. Carbon 14, carbon 13 and oxygen 18 in carbonate sediments from lake Titicaca. Preliminary estimates of sedimentation rate and paleoclimatological attempt

    International Nuclear Information System (INIS)

    Fontes, J.-C.; Boulange, Bruno; Rodrigo, L.-A.

    1981-01-01

    Stable isotope and radiocarbon measurements in carbonates from Titicaca lake indicate equilibrium with lake water and atmospheric CO 2 . Average sedimentation rate is close to 0,5 mm.yr -1 for the last millenium which was marked by large fluctuations of the hydrologic balance and lake level [fr

  1. Carbon 14, carbon 13 and oxygen 18 in carbonate sediments from Lake Titicaca. Preliminary estimates of sedimentation rate and paleoclimatological attempt

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, J.C. (Paris-11 Univ., 91 - Orsay (France)); Boulange, B. (Orstom, 75 - Paris (France)); Rodrigo, L.A. (Universidad Mayor de San Andres, La Paz (Bolivia). Lab. de Fisica Cosmica de Chacaltaya)

    1981-07-06

    Stable isotope and radiocarbon measurements in carbonates from Lake Titicaca indicate equilibrium with lake water and atmospheric CO/sub 2/. Average sedimentation rate is close to 0,5 mm.yr/sup -1/ for the last millenium which was marked by large fluctuations of the hydrologic balance and lake level.

  2. Synthesis of methyl ((chloro-2 ethyl)-3 nitroso-3 Ureido)-3 Didesoxy-2,3. alpha. -D-Arabino-hexopyrannoside labelled with carbon-14 or carbon-13 (CY 233 - SR 90008). Synthese du methyl ((chloro-2 ethyl)-3 nitroso-3 Ureido)-3 Didesoxy-2,3. alpha. -D-Arabino-hexopyrannoside marque au carbone-14 ou carbone-13 (CY 233 - SR 90008)

    Energy Technology Data Exchange (ETDEWEB)

    Sion, R.; Schumer, A.; Durme, E. van (Sanofi Recherche, Brussels (Belgium)); Gouyette, A. (Centre de Lutte Contre le Cancer Gustave-Roussy, 94 - Villejuif (France)); Geslin, M.; Fournier, J.P.; Roger, P. (Sanofi Recherche, Montrouge (France). Inst. Choay); Berger, Y. (Sanofi Recherche, Montpellier (France))

    1990-06-01

    CY 233 (Ecomustine or SR 90098) is a new antitumour nitrosourea: it is characterized by a 2-chloroethylnitrosourea substituent on a dideoxycarbohydrate. It has been labelled with {sup 14}C on (a) the carbonyl group of the urea in four stages starting with {sup 14}COCl{sub 2}, (b) the second carbon of the chloroethyl group in four stages starting with ({sup 14}C) ethanolamine, and (c) on the methyl group on the anomeric centre of the carbohydrate in three stages starting with {sup 14}CH{sub 3}OH. The final position was also labelled with {sup 13}C starting with {sup 13}CH{sub 3}OH. These differently labelled compounds are suitable for mechanistic studies of antitumour activity. (author).

  3. Metabolism of tritium- and carbon-14-labeled tiamulin in dogs, rats, and pigs.

    Science.gov (United States)

    Dreyfuss, J; Singhvi, S M; Shaw, J M; Egli, P; Ross, J J; Czok, R; Nefzger-Biessels, M; Battig, F; Schuster, I; Schmook, F

    1979-05-01

    The metabolism of tiamulin hydrogen fumarate, labeled with 3H, 14C, or both, was studied in dogs, rats, and weanling pigs. After a dose of radiolabeled tiamulin, all three species excreted more radioactivity in feces (via bile) than in urine. Dogs absorbed 86% of a single oral dose of tiamulin-3H, and the disposition of the compound was similar after a single or multiple dosage regimen. The ratio of antimicrobial activity to total radioactivity in dog plasma was only about 0.25, and was still less in dog urine. After dosing with tiamulin-14C, rats and pigs excreted at least 1% of the dose as 14CO2 in expired air. In dual-labeled studies, pigs excreted less total 14C than 3H and had greater residues of 14C than 3H in edible tissues, blood, and plasma. After the administration of tiamulin-14C to pigs, radioactivity was incorporated into liver glycogen, indicating metabolic cleavage of the side chain of tiamulin. Tiamulin-3H is the isotopically-labeled compound of choice for studying metabolism and tissue residues in animals.

  4. Comparison on the production of radionuclides in 1.4 GeV proton irradiated LBE targets of different thickness

    CERN Document Server

    Maiti, Moumita; Mendonça, Tania M; Stora, Thierry; Lahiri, Susanta

    2014-01-01

    This is the first report on the inventory of radionuclides produced in 1.4 GeV proton induced reaction on Lead-Bismuth Eutectic (LBE) targets. LBE targets of 6 mm diameter and 1 to 8 mm lengths were irradiated with 1.4 GeV protons. The radionuclides ranging from Be-7 (53.12 days) to Po-207 (5.8 h) were identified in the samples with the help of time resolved gamma-ray spectroscopy. However, there is no signature of formation of At radioisotopes, which can be produced by the interaction of secondary particles, typical for thick targets.

  5. Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa.

    Science.gov (United States)

    Sonnleitner, Elisabeth; Valentini, Martina; Wenner, Nicolas; Haichar, Feth el Zahar; Haas, Dieter; Lapouge, Karine

    2012-01-01

    The opportunistic human pathogen Pseudomonas aeruginosa is able to utilize a wide range of carbon and nitrogen compounds, allowing it to grow in vastly different environments. The uptake and catabolism of growth substrates are organized hierarchically by a mechanism termed catabolite repression control (Crc) whereby the Crc protein establishes translational repression of target mRNAs at CA (catabolite activity) motifs present in target mRNAs near ribosome binding sites. Poor carbon sources lead to activation of the CbrAB two-component system, which induces transcription of the small RNA (sRNA) CrcZ. This sRNA relieves Crc-mediated repression of target mRNAs. In this study, we have identified novel targets of the CbrAB/Crc system in P. aeruginosa using transcriptome analysis in combination with a search for CA motifs. We characterized four target genes involved in the uptake and utilization of less preferred carbon sources: estA (secreted esterase), acsA (acetyl-CoA synthetase), bkdR (regulator of branched-chain amino acid catabolism) and aroP2 (aromatic amino acid uptake protein). Evidence for regulation by CbrAB, CrcZ and Crc was obtained in vivo using appropriate reporter fusions, in which mutation of the CA motif resulted in loss of catabolite repression. CbrB and CrcZ were important for growth of P. aeruginosa in cystic fibrosis (CF) sputum medium, suggesting that the CbrAB/Crc system may act as an important regulator during chronic infection of the CF lung.

  6. Photoperiodic effects on short-pulse 14C assimilation and overall carbon and nitrogen allocation patterns in contrasting quinoa cultivars

    DEFF Research Database (Denmark)

    Bendevis, Mira Arpe; Sun, Yujie; Rosenqvist, Eva

    2014-01-01

    ' and photoperiod neutral cv. 'Titicaca' were studied under short (10h) and long (17.5h) days, with respect to C and N distribution as well as partitioning of newly assimilated C to plant organs. An extended photoperiod resulted in 14C decreasingly being allocated to stem growth and lower leaves in 'Titicaca...... with an immediate increase in carbon allocation to upper leaves, and over time to the reproductive structures, resulting in a more than 50% increase in final yield. Collectively the results indicate that even though the photoperiod sensitive cultivar flowered under long photoperiod it did not develop seeds, whereas...

  7. Bioinformatic analysis of the distribution of inorganic carbon transporters and prospective targets for bioengineering to increase Ci uptake by cyanobacteria.

    Science.gov (United States)

    Gaudana, Sandeep B; Zarzycki, Jan; Moparthi, Vamsi K; Kerfeld, Cheryl A

    2015-10-01

    Cyanobacteria have evolved a carbon-concentrating mechanism (CCM) which has enabled them to inhabit diverse environments encompassing a range of inorganic carbon (Ci: [Formula: see text] and CO2) concentrations. Several uptake systems facilitate inorganic carbon accumulation in the cell, which can in turn be fixed by ribulose 1,5-bisphosphate carboxylase/oxygenase. Here we survey the distribution of genes encoding known Ci uptake systems in cyanobacterial genomes and, using a pfam- and gene context-based approach, identify in the marine (alpha) cyanobacteria a heretofore unrecognized number of putative counterparts to the well-known Ci transporters of beta cyanobacteria. In addition, our analysis shows that there is a huge repertoire of transport systems in cyanobacteria of unknown function, many with homology to characterized Ci transporters. These can be viewed as prospective targets for conversion into ancillary Ci transporters through bioengineering. Increasing intracellular Ci concentration coupled with efforts to increase carbon fixation will be beneficial for the downstream conversion of fixed carbon into value-added products including biofuels. In addition to CCM transporter homologs, we also survey the occurrence of rhodopsin homologs in cyanobacteria, including bacteriorhodopsin, a class of retinal-binding, light-activated proton pumps. Because they are light driven and because of the apparent ease of altering their ion selectivity, we use this as an example of re-purposing an endogenous transporter for the augmentation of Ci uptake by cyanobacteria and potentially chloroplasts.

  8. Effect of altered intraraceme competition on carbon-14-labeled assimilate and abscisic acid in soybean

    International Nuclear Information System (INIS)

    Spollen, W.G.; Wiebold, W.J.; Glenn, S.

    1986-01-01

    Abscission probability varies among floral positions within soybean [Glycine max (L.) Merr.] racemes. Field grown soybean plants were used to determine the distribution of translocated 14 C-labeled photosynthate and abscisic acid (ABA) among reproductive structures differing for abscission probability. The effect of proximal pods on the translocation of 14 C-labeled photosynthate to and ABA concentration in distal pods (floral positions 3 and above) was also evaluated. Treatments consisted of removing or not removing the two proximal pods (floral positions 1 and 2) from the major racemes at nodes 8 and 10 in 1982 and 8, 10, and 12 in 1983. Six days after treatment in 1982 and 12 days after treatment in 1983. 14 C-translocation from the leaf at the node of interest was determined after exposure to 14 CO 2 . On the same day, distal pods were collected for determination of ABA by gas chromatography. For untreated plants, proximal and distal pods accounted for 50 and 7% of the translocated 14 C, respectively. Proximal pod removal had no effect on 14 C retained by the source leaf (72%) or the concentration of ABA in seeds. Concentration of ABA in pod wall of distal pods was increased by proximal pod removal in only one instance. Amount of 14 C translocated to distal pods and distal pod specific activity were not altered by proximal pod removal in 1982 but were increased in 1983. The different treatment effect between years may indicate that distal pods undergo a period of adjustment after proximal pod removal. An understanding of processes that occur during the adjustment period may be necessary before the mechanism of soybean reproductive abscission is known

  9. The long-term trend of carbon-14 level in Japan

    International Nuclear Information System (INIS)

    Yoshikazu Inoue; Tetsuo Iwakura

    1993-01-01

    The long-term trend of the specific activity of 14 C in terms of dpm/gC from 1942 to 1991 in the natural environment in Japan was obtained as baseline data by analyzing plant components so as to evaluate the collective effective dose. It was deduced that the specific activity of 14 C in plants reflected well that of atmospheric 14 CO 2 . Uniform distribution of the specific activity in plant among species as well as the production places was confirmed. The Suess effect was observed clearly for a period of 10 years from the late 1960's. The 14 C level was at about 13.7 dpm/gC due to cosmic ray production in 1940's, and reached a peak of about 24.5 dpm/gC in 1963 due to nuclear weapons testing and decreased to 15.6 dpm/gC in 1991. Fermented alcohol proved to be a convenient indicator for measuring the annual mean specific activity of 14 C in the atmosphere. (3 figs.)

  10. Evaluation of carbon-14 (C{sup 14}) levels of terrestrial and marine food products of the environment of the site of Cogema La Hague; Evaluation des niveaux de carbone-14 ({sup 14}C) des denrees alimentaires terrestres et marines de l'environnement du site de COGEMA - La Hague

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-04-15

    This evaluation has for object to inform about the levels in carbon 14 in the environment of the factories of La Hague. Two sectors were differentiated on one hand the terrestrial environment, and on the other hand the marine environment. The investigations concerned first and foremost food products stemming as the vegetable culture (vegetables) or individual breeding (milk, eggs) but also foodstuffs stemming from the local agriculture (cereal). In touch with the second sector, the marine environment, the sampling concerned the accessible products of the sea by all and those locally marketed (fishes, molluscs, shellfishes). The different results are presented in tables. (N.C.)

  11. Carbon-14-labeled 2,3,7,8- and 1,2,7,8-tetrachlorodibenzofuran

    International Nuclear Information System (INIS)

    Gray, A.P.; McClellan, W.J.; Dipinto, V.M.

    1981-01-01

    Both 2,3,7,8- and 1,2,7,8- tetrachlorodibenzofuran -U 14 C, specific activity 57 mCi/mmol, have been obtained in low yield but at > 98% purity via Pschorr cyclization of o-phenoxyaniline -U 14 C, chlorination of the resultant dibenzofuran and separation of the tetrachloro isomers by hplc. The lower yields obtained in the Pschorr cyclization of 'hot' o-phenoxyaniline in comparison with the 'cold' material are postulated to result from enhanced homolytic relative to heterolytic cleavage of the 'hot' diazonium ion leading to a 'hot' free radical which polymerizes. The completely anomalous results observed in the attempted palladium acetate-mediated cyclization of diphenyl ether- U 14 C are likewise interpreted in terms of the intervention of a 'hot' free radical. (author)

  12. Targeting single-walled carbon nanotubes for the treatment of breast cancer using photothermal therapy

    Science.gov (United States)

    Neves, Luis Filipe Ferreira

    To develop a therapeutic system with cancer cell selectivity, the present study evaluated a possible specific and localized tumor treatment. Phosphatidylserine (PS) exposure on the external face of the cell membrane is almost completely exclusive to cancer cells and endothelial cells in the tumor vasculature. The human protein annexin V is known to have strong calcium-dependent binding to anionic phospholipids such as PS. This protein was studied for targeting single-walled carbon nanotubes (SWNTs) to the vasculature of breast tumors. The synthesis of the protein annexin V, by a pET vector in Escherichia coli, constitutes the first phase of this study. Recombinant annexin V was purified from the cell lysate supernatant by immobilized metal affinity chromatography. The overall production of purified annexin V protein was 50 mg/L. The binding ability of the protein annexin V was evaluated by determining the dissociation constant when incubated with proliferating human endothelial cells in vitro. The dissociation constant, Kd, was measured to be 0.8 nM, indicating relatively strong binding. This value of Kd is within the range reported in the literature. Single-walled carbon nanotubes (SWNTs) were functionalized with annexin V using two intermediate linkers (containing FMOC and DSPE) resulting in stable suspensions. The SWNT and protein concentrations were 202 mg/L and 515 mg/L, respectively, using the linker with DSPE (average of nine preparations). The conjugation method that used the DSPE-PEG-maleimide linker allowed to successfully conjugate the SWNTs with final concentrations approximately five times higher than the linker containing FMOC. The conjugation method used has a non-covalent nature, and therefore the optical properties of the nanotubes were preserved. The conjugate was also visually observed using atomic force microscopy (AFM), allowing to verify the presence of the protein annexin V on the surface of the nanotubes, with an height ranging between 2

  13. On the labelling of insuline and insuline derivatives with tritium and carbon-14

    International Nuclear Information System (INIS)

    Uschkoreit, J.

    1979-01-01

    Two different labelling methods were investigated. By means of the Wilzbach labelling with diaminosuberoylinsuline the insuline is irreversibly altered. As a second method the reductive methylation was used, in doing so it was possible to distinguish between mono and dimethylated parts of the reaction product by using C-14 labelled formaldehyde. Furthermore four N,N-dimethylated insuline derivatives were isolated with yields of 25 until 35%. By using C-14 and h-3 labelled reagents insuline can be labelled doubly. Moreover N-terminal amino groups could be protected irreversibly with this method. Furthermore structure-function investigations and investigations concerning the insuline metabolism were done. (SPI) [de

  14. Gas-phase noncovalent functionalization of carbon nanotubes with a Ni(II) tetraaza[14]annulene complex

    Science.gov (United States)

    Basiuk, Vladimir A.; Henao-Holguín, Laura Verónica; Álvarez-Zauco, Edgar; Bassiouk, María; Basiuk, Elena V.

    2013-04-01

    The noncovalent functionalization of carbon nanotubes (CNTs) with aromatic polyazamacrocyclic compounds, based on π-π-interactions, keeps the intrinsic electronic structure of CNTs totally intact and allows for combining unique properties of the two interacting components. In addition to porphyrins and phthalocyanines, there are other, simpler compounds exhibiting similar properties, potentially useful for photovoltaic, catalytic and electrochemical applications: for example, tetraaza[14]annulenes. Many of them are highly thermally stable, which makes it possible to employ physical vapor deposition for the preparation of macrocycle-nanotube hybrids. One of such compounds is Ni(II) complex of 5,7,12,14-tetramethyldibenzo-1,4,8,11-tetraazacyclotetradeca-3,5,7,10,12,14-hexaene (also called Ni(II)-tetramethyldibenzotetraaza[14]annulene, or NiTMTAA for simplicity). In the present work, we attempted the noncovalent functionalization of both single-walled and multi-walled CNTs with NiTMTAA in the gas phase at two selected temperatures of 220 and 270 °C, which does not require the use of organic solvents and therefore can be considered as ecologically friendly. The nanohybrids obtained were characterized by means of scanning and transmission electron microscopy, energy dispersive X-ray, Fourier-transform infrared and Raman spectroscopy, as well as thermogravimetric analysis. An additional insight into the structure of adsorption complexes of NiTMTAA on CNTs was provided from density functional theory and molecular mechanics calculations.

  15. Gas-phase noncovalent functionalization of carbon nanotubes with a Ni(II) tetraaza[14]annulene complex

    Energy Technology Data Exchange (ETDEWEB)

    Basiuk, Vladimir A., E-mail: basiuk@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, México D.F. (Mexico); Henao-Holguín, Laura Verónica [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, México D.F. (Mexico); Álvarez-Zauco, Edgar [Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510, México D.F. (Mexico); Bassiouk, María [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, México D.F. (Mexico); Basiuk, Elena V. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, México D.F. (Mexico)

    2013-04-01

    The noncovalent functionalization of carbon nanotubes (CNTs) with aromatic polyazamacrocyclic compounds, based on π–π-interactions, keeps the intrinsic electronic structure of CNTs totally intact and allows for combining unique properties of the two interacting components. In addition to porphyrins and phthalocyanines, there are other, simpler compounds exhibiting similar properties, potentially useful for photovoltaic, catalytic and electrochemical applications: for example, tetraaza[14]annulenes. Many of them are highly thermally stable, which makes it possible to employ physical vapor deposition for the preparation of macrocycle–nanotube hybrids. One of such compounds is Ni(II) complex of 5,7,12,14-tetramethyldibenzo-1,4,8,11-tetraazacyclotetradeca-3,5,7,10,12, 14-hexaene (also called Ni(II)-tetramethyldibenzotetraaza[14]annulene, or NiTMTAA for simplicity). In the present work, we attempted the noncovalent functionalization of both single-walled and multi-walled CNTs with NiTMTAA in the gas phase at two selected temperatures of 220 and 270 °C, which does not require the use of organic solvents and therefore can be considered as ecologically friendly. The nanohybrids obtained were characterized by means of scanning and transmission electron microscopy, energy dispersive X-ray, Fourier-transform infrared and Raman spectroscopy, as well as thermogravimetric analysis. An additional insight into the structure of adsorption complexes of NiTMTAA on CNTs was provided from density functional theory and molecular mechanics calculations.

  16. Gas-phase noncovalent functionalization of carbon nanotubes with a Ni(II) tetraaza[14]annulene complex

    International Nuclear Information System (INIS)

    Basiuk, Vladimir A.; Henao-Holguín, Laura Verónica; Álvarez-Zauco, Edgar; Bassiouk, María; Basiuk, Elena V.

    2013-01-01

    The noncovalent functionalization of carbon nanotubes (CNTs) with aromatic polyazamacrocyclic compounds, based on π–π-interactions, keeps the intrinsic electronic structure of CNTs totally intact and allows for combining unique properties of the two interacting components. In addition to porphyrins and phthalocyanines, there are other, simpler compounds exhibiting similar properties, potentially useful for photovoltaic, catalytic and electrochemical applications: for example, tetraaza[14]annulenes. Many of them are highly thermally stable, which makes it possible to employ physical vapor deposition for the preparation of macrocycle–nanotube hybrids. One of such compounds is Ni(II) complex of 5,7,12,14-tetramethyldibenzo-1,4,8,11-tetraazacyclotetradeca-3,5,7,10,12, 14-hexaene (also called Ni(II)-tetramethyldibenzotetraaza[14]annulene, or NiTMTAA for simplicity). In the present work, we attempted the noncovalent functionalization of both single-walled and multi-walled CNTs with NiTMTAA in the gas phase at two selected temperatures of 220 and 270 °C, which does not require the use of organic solvents and therefore can be considered as ecologically friendly. The nanohybrids obtained were characterized by means of scanning and transmission electron microscopy, energy dispersive X-ray, Fourier-transform infrared and Raman spectroscopy, as well as thermogravimetric analysis. An additional insight into the structure of adsorption complexes of NiTMTAA on CNTs was provided from density functional theory and molecular mechanics calculations.

  17. Targeting carbonic anhydrase to treat diabetic retinopathy: Emerging evidences and encouraging results

    Energy Technology Data Exchange (ETDEWEB)

    Weiwei, Zhang [Department of Endocrinology and Metabolism, HuaShan Hospital, Institute of Endocrinology and Diabetology, Shanghai Medical College, Fudan University, No. 12 Wulumuqi Road, Shanghai 200040 (China); Hu, Renming, E-mail: taylorzww@gmail.com [Department of Endocrinology and Metabolism, HuaShan Hospital, Institute of Endocrinology and Diabetology, Shanghai Medical College, Fudan University, No. 12 Wulumuqi Road, Shanghai 200040 (China)

    2009-12-18

    Diabetic retinopathy (DR) is the leading cause of vision loss among working-age populations in developed countries. Current treatment options are limited to tight glycemic, blood pressure control and destructive laser surgery. Carbonic anhydrases (CAs) are a group of enzymes involving in the rapid conversion of carbon dioxide to bicarbonate and protons. Emerging evidences reveal CA inhibitors hold the promise for the treatment of DR. This article summarizes encouraging results from clinical and animal studies, and reviews the possible mechanisms.

  18. Targeting carbonic anhydrase to treat diabetic retinopathy: Emerging evidences and encouraging results

    International Nuclear Information System (INIS)

    Weiwei, Zhang; Hu, Renming

    2009-01-01

    Diabetic retinopathy (DR) is the leading cause of vision loss among working-age populations in developed countries. Current treatment options are limited to tight glycemic, blood pressure control and destructive laser surgery. Carbonic anhydrases (CAs) are a group of enzymes involving in the rapid conversion of carbon dioxide to bicarbonate and protons. Emerging evidences reveal CA inhibitors hold the promise for the treatment of DR. This article summarizes encouraging results from clinical and animal studies, and reviews the possible mechanisms.

  19. A First Look at Target Mode Retrievals of CO2 from the Orbiting Carbon Observatory-2 (OCO-2)

    Science.gov (United States)

    Natraj, V.; Taylor, T.; Smyth, M.; Fisher, B.; O'Dell, C.; Pollock, H. R.; Crisp, D.

    2014-12-01

    The Orbiting Carbon Observatory-2 (OCO-2) is NASA's first dedicated Earth remote sensing satellite to study atmospheric carbon dioxide from space, and was launched successfully on July 2, 2014. OCO-2 is designed to quantify the sources and sinks of CO2by making highly precise measurements of its column abundance. OCO-2 has three science observation modes - nadir, glint and target. In the nadir mode, the satellite points the instrument to the local nadir, so that data can be collected along the ground track just below the spacecraft. In the glint mode, the spacecraft points the instrument toward the bright "glint" spot, where solar radiation is specularly reflected from the surface. In the target mode, the Observatory will lock its view onto a specific surface location, and will scan back and forth over that target while flying overhead. A target track pass can last for up to 9 minutes. Over that time period, the Observatory can acquire as many as 12,960 samples at local zenith angles that vary between 0° and 85°. Here, we analyze target track measurements over several of the OCO-2 validation sites where ground-based solar-looking Fourier Transform Spectrometers are located. The target scan serves two purposes. The first is to collect a large number of measurements over surface calibration and validation targets to assess the precision and accuracy of the retrieved column averaged CO2 dry air mole fraction (XCO2). The second is to look for spatial variations in column averaged CO2 dry air mole fraction (XCO2) in the vicinity of the target that could compromise the value of the measurements for calibration or validation. To meet both requirements, we compare XCO2 retrievals as a function of both observation angle and scan location, and investigate whether those variations are coming from instrument calibration, algorithmic deficiencies, aerosols/clouds or real CO2variations. Further, simulated retrievals indicate that target observations can show large sensitivity

  20. The preparation of nucleotides uniformly labelled with carbon-14 by biosinthetic methods. Isolation of adenilic, uridilic, cytidilic and guanlic acids, from the alkaline hydrolisate of escherichia coli RNA

    International Nuclear Information System (INIS)

    Garcia Pineda, D.; Pacheco Lopez, J.

    1978-01-01

    A method is described for the preparation and analysis of adenilic, uridilic, cytidylic and guanilic acids, labelled with carbon 14. Escherichia coli cells have been labelled by growing them in media containing glucose-carbon 14 as their only source of carbon. RNA is isolated from the cells, and after hydrolisis of the molecule the resulting nucleotides are separated by gel filtration and exchange chromatography. Chemical and radiochemical purity of the isolated nucleotides is determined and also its specific radioactivity. The distribution of radioactivity incorporated in the cell among different groups of molecular species is analyse. (author)

  1. Carbon-14 based determination of the biogenic fraction of industrial CO2 emissions : Application and validation

    NARCIS (Netherlands)

    Palstra, S. W. L.; Meijer, H. A. J.

    The C-14 method is a very reliable and sensitive method for industrial plants, emission authorities and emission inventories to verify data estimations of biogenic fractions of CO2 emissions. The applicability of the method is shown for flue gas CO2 samples that have been sampled in I-h intervals at

  2. Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

    International Nuclear Information System (INIS)

    Lawrie, K.W.M.; Novelli, C.E.A.; Saunders, David

    1995-01-01

    The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano- 14 C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author)

  3. Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lawrie, K.W.M.; Novelli, C.E.A.; Saunders, David [SmithKline Beecham Pharmaceuticals Research and Development, Harlow (United Kingdom). Synthetic Isotope Chemistry Dept.; Coates, W.J. [SmithKline Beecham Pharmaceuticals Research and Development, Welwyn (United Kingdom)

    1995-09-01

    The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano-{sup 14}C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author).

  4. Simple analytical technique for liquid scintillation counting of environmental carbon-14 using gel suspension method

    International Nuclear Information System (INIS)

    Okai, Tomio; Wakabayashi, Genichiro; Nagao, Kenjiro; Matoba, Masaru; Ohura, Hirotaka; Momoshima, Noriyuki; Kawamura, Hidehisa

    2000-01-01

    A simple analytical technique for liquid scintillation counting of environmental 14 C was developed. Commercially available gelling agent, N-lauroyl-L -glutamic -α,γ-dibutylamide, was used for the gel-formation of the samples (gel suspension method) and for the subsequent liquid scintillation counting of 14 C in the form of CaCO 3 . Our procedure for sample preparation is much simpler than that of the conventional methods and requires no special equipment. Self absorption, stability and reproducibility of gel suspension samples were investigated in order to evaluate the characteristics of the gel suspension method for 14 C activity measurement. The self absorption factor is about 70% and slightly decrease as CaCO 3 weight increase. This is considered to be mainly due to the absorption of β-rays and scintillation light by the CaCO 3 sample itself. No change of the counting rate for the gel suspension sample was observed for more than 2 years after the sample preparation. Four samples were used for checking the reproducibility of the sample preparation method. The same values were obtained for the counting rate of 24 C activity within the counting error. No change of the counting rate was observed for the 're-gelated' sample. These results show that the gel suspension method is appropriate for the 14 C activity measurement by the liquid scintillation counting method and useful for a long-term preservation of the sample for repeated measurement. The above analytical technique was applied to actual environmental samples in Fukuoka prefecture, Japan. Results obtained were comparable with those by other researchers and appear to be reasonable. Therefore, the newly developed technique is useful for the routine monitoring of environmental 14 C. (author)

  5. Effects of entrainment through Oconee Nuclear Station on carbon-14 assimilation rates of phytoplankton

    International Nuclear Information System (INIS)

    Kreh, T.V.; Derwort, J.E.

    1976-01-01

    Carbon assimilation rates of phytoplankton communities entrained through Oconee Nuclear Station were measured on six dates during 1974. Thermal, mechanical, condenser, and multiple entrainment effects on uptake rates were compared by incubating samples in vitro in controlled-temperature water baths. Duplicate light and dark bottles containing water from four cooling-system locations were exposed to temperatures approximating intake and discharge temperatures. The relationships were variable, but exposure of the hypolimnetic intake water at near-discharge temperatures (thermal effect) stimulated primary productivity in four of six experiments. Multiple entrainment and mechanical effects caused no consistent change in assimilation rates

  6. Using Targeted Active-Learning Exercises and Diagnostic Question Clusters to Improve Students' Understanding of Carbon Cycling in Ecosystems

    Science.gov (United States)

    Maskiewicz, April Cordero; Griscom, Heather Peckham; Welch, Nicole Turrill

    2012-01-01

    In this study, we used targeted active-learning activities to help students improve their ways of reasoning about carbon flow in ecosystems. The results of a validated ecology conceptual inventory (diagnostic question clusters [DQCs]) provided us with information about students' understanding of and reasoning about transformation of inorganic and organic carbon-containing compounds in biological systems. These results helped us identify specific active-learning exercises that would be responsive to students' existing knowledge. The effects of the active-learning interventions were then examined through analysis of students' pre- and postinstruction responses on the DQCs. The biology and non–biology majors participating in this study attended a range of institutions and the instructors varied in their use of active learning; one lecture-only comparison class was included. Changes in pre- to postinstruction scores on the DQCs showed that an instructor's teaching method had a highly significant effect on student reasoning following course instruction, especially for questions pertaining to cellular-level, carbon-transforming processes. We conclude that using targeted in-class activities had a beneficial effect on student learning regardless of major or class size, and argue that using diagnostic questions to identify effective learning activities is a valuable strategy for promoting learning, as gains from lecture-only classes were minimal. PMID:22383618

  7. Using targeted active-learning exercises and diagnostic question clusters to improve students' understanding of carbon cycling in ecosystems.

    Science.gov (United States)

    Maskiewicz, April Cordero; Griscom, Heather Peckham; Welch, Nicole Turrill

    2012-01-01

    In this study, we used targeted active-learning activities to help students improve their ways of reasoning about carbon flow in ecosystems. The results of a validated ecology conceptual inventory (diagnostic question clusters [DQCs]) provided us with information about students' understanding of and reasoning about transformation of inorganic and organic carbon-containing compounds in biological systems. These results helped us identify specific active-learning exercises that would be responsive to students' existing knowledge. The effects of the active-learning interventions were then examined through analysis of students' pre- and postinstruction responses on the DQCs. The biology and non-biology majors participating in this study attended a range of institutions and the instructors varied in their use of active learning; one lecture-only comparison class was included. Changes in pre- to postinstruction scores on the DQCs showed that an instructor's teaching method had a highly significant effect on student reasoning following course instruction, especially for questions pertaining to cellular-level, carbon-transforming processes. We conclude that using targeted in-class activities had a beneficial effect on student learning regardless of major or class size, and argue that using diagnostic questions to identify effective learning activities is a valuable strategy for promoting learning, as gains from lecture-only classes were minimal.

  8. Contribution of sorption, DOC transport and microbial interactions to the 14C age of a soil organic carbon profile: Insights from a calibrated process model

    NARCIS (Netherlands)

    Ahrens, B.; Braakhekke, M.C.; Guggenberger, G.; Schrumpf, M.; Reichstein, M.

    2015-01-01

    Profiles of soil organic carbon (SOC) are often characterized by a steep increase of 14C age with depth, often leading to subsoil 14C ages of more than 1000 years. These observations have generally been reproduced in SOC models by introducing a SOC pool that decomposes on the time-scale of

  9. Contribution of sorption, DOC transport and microbial interactions to the 14C age of a soil organic carbon profile : Insights from a calibrated process model

    NARCIS (Netherlands)

    Ahrens, Bernhard; Braakhekke, M.C.|info:eu-repo/dai/nl/343063689; Guggenberger, Georg; Schrumpf, Marion; Reichstein, Markus

    2015-01-01

    Profiles of soil organic carbon (SOC) are often characterized by a steep increase of 14C age with depth, often leading to subsoil 14C ages of more than 1000 years. These observations have generally been reproduced in SOC models by introducing a SOC pool that decomposes on the time-scale of

  10. A content analysis of food references in television programming specifically targeting viewing audiences aged 11 to 14 years.

    Science.gov (United States)

    Roseman, Mary G; Poor, Morgan; Stephenson, Tammy J

    2014-01-01

    Examine food in cable television programming specifically targeting 11- to 14-year-olds ("tweens"). Content analysis of food-related scenes (FRS)-in which food was shown, mentioned, and/or consumed-in 880 minutes of programming was conducted. Five days of afternoon/early evening television programs on the Disney Channel. Food references were compared with USDA MyPlate and classified according to modified Ratio of Recommended to Restricted Food Components. The authors found 331 FRS, averaging 16.6 scenes/h. Preponderance of FRS was physiological needs (40.7%), followed by display (10%), party (8.5%), social event (8%), and retail store (6.6%). Snacks dominated 41% of FRS, and breakfast, lunch, and dinner were much lower in frequency. Half of FRS was visual only, followed by verbal only. Food references were not congruent with MyPlate recommendations; 42% of food items did not fit into MyPlate food groups. Only 24% of food items were fruit or vegetables, which is considerably less than recommended by MyPlate guidelines. Using modified Ratio of Recommended to Restricted Food Components, 66% of food items scored food, which likely influences tweens' attitudes and behaviors. Television programming may consider past approaches to tobacco smoking and health messages on television. More attention is warranted regarding television programming by nutrition educators, researchers, health professionals, and industry specialists. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  11. Sources of Respired Carbon in a Northern Minnesota Ombrotrophic Spruce Bog: Preliminary 14C Results from the SPRUCE Site.

    Science.gov (United States)

    Guilderson, T. P.; McNicol, G.; Machin, A.; Hanson, P. J.; McFarlane, K. J.; Osuna, J. L.; Pett-Ridge, J.; Singleton, M. J.

    2014-12-01

    A significant uncertainty in future land-surface carbon budgets is the response of wetlands to climate change. A corollary and related question is the future net climate (radiative) forcing impact from wetlands. Active wetlands emit both CO2 and CH4 to the atmosphere. CH4 is, over a few decades, a much more potent greenhouse gas than CO2. CO2 has a longer atmospheric lifetime and a longer 'tail' to its radiative influence. Whether wetlands are a net source or sink of atmospheric carbon under future climate change will depend on ecosystem response to rising temperatures and elevated CO2. The largest uncertainty in future wetland C-budgets, and their climate forcing is the stability of the large below-ground carbon stocks, often in the form of peat, and the partitioning of CO2 and CH4 released via ecosystem respiration. In advance of a long-term experimental warming and elevated CO2 manipulation at the DOE Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) site in the Marcell Experimental Forest, we have characterized the source of respired carbon used for both the production of CO2 and CH4. Samples were collected in early June, late July, and will be collected in early September from three large (~1.1 m2, ~0.5m3) chambers from the control plot, and two of the experimental plots selected for heating (+9°C, +4.5°C). Early June fluxes from the three chambers were ~5500 mgC-m-2-d-1 and ~16 mgC-m-2-d-1 for CO2 and CH4 respectively. Radiocarbon analysis of CO2 and CH4 indicate that the source for the respired carbon is for the most part recent, with most 14C values between 30 and 40‰ - i.e., carbon that was photosynthetically fixed in the last few years. In concert with rising air and ground temperatures fluxes in late July increased to ~6500 mgC-m-2-d-1 and ~86 mgC-m-2-d-1. Although deep-heating was initiated in mid to late June we hypothesize that the July respiration signal is dominated by the regular seasonal cycle of natural warming

  12. Background carbon-14 levels in UK foodstuffs, 1981-1995, based upon a 1992 survey

    International Nuclear Information System (INIS)

    Otlet, R.L.; Walker, A.J.; Fulker, M.J.; Collins, C.

    1997-01-01

    Knowledge of the current 'natural' background level is important to 14 C-related studies, especially dose assessments in the vicinity of and distant from nuclear establishments since its value must be subtracted from measured levels to determine local enhancement. Although measurements have been made world-wide to monitor the decline of the background level, from its peak in the early 1960s to the present, there exists a paucity of precise data for UK natural materials. Accordingly this study was carried out to establish an average figure for the 'natural' 14 C level in foodstuffs in 1992 from a survey of materials collected from a wide range of sites over England and Wales, using this single year value, to infill missing years prior to 1992 and to extrapolate from some years afterwards. Results are presented from the survey, and for the derived extrapolation with comparison made with measurements from other laboratories. (Author)

  13. Carbon-14 methylation of the 2-methylbutyryl side chain of mevinolin and its analogs

    International Nuclear Information System (INIS)

    Prakash, S.R.; Ellsworth, R.L.

    1988-01-01

    A one step procedure for the preparation of three labeled mevinolin analogs possessing the 2,2-dimethylbutyryloxy side chain is described. Three lactones were converted into potassium salts of their corresponding di or trihydroxy carboxylic acids from which anionic ester enolates were generated and alkylated with [ 14 ]methyl iodide. Workup and purification by reverse phase HPLC provided the three radiochemically pure mevinolin analogs. The labeled lactones were converted into ammonium salts of their corresponding di or trihydroxy acids. (author)

  14. A Chlorine-36 and Carbon-14 Study of the Role of Chlorine in the Forest Ecosystem

    Czech Academy of Sciences Publication Activity Database

    Matucha, Miroslav; Gryndler, Milan; Forczek, Sándor; Schröder, P.; Bastviken, D.; Rohlenová, Jana; Uhlířová, H.; Fuksová, Květoslava

    2007-01-01

    Roč. 50, č. 1 (2007), s. 1-3 ISSN 0362-4803 R&D Projects: GA ČR GA522/02/0874; GA ČR GA526/05/0636 Institutional research plan: CEZ:AV0Z50380511 Keywords : [14C]-synthesis * labeled compounds * tetrahydrocyclopenta[b]indol-3-yl acetic acid Subject RIV: EF - Botanics Impact factor: 1.142, year: 2007

  15. Differential cross sections for carbon neutron elastic and inelastic scattering from 8.0 to 14.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Haouat, G.; Lachkar, J.; Patin, Y.; Sigaud, J.; Cocu, F.

    1975-06-01

    Differential elastic and inelastic cross sections for fast neutrons scattered by carbon have been measured between 8.0 and 14.5 MeV. No experimental results on {sup 12}C seem to have been reported, at this time, between 9 and 14 MeV. A complete and consistent set of data on carbon, including total, elastic and inelastic, (n,α) and (n,n'3α) cross sections, is now available for energies below 14.5MeV.

  16. Development of Carbon-14 Waste Destruction and Recovery System Using AC Plasma Torch Technology Final Report CRADA No. TC02108.0

    Energy Technology Data Exchange (ETDEWEB)

    Althouse, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McKannay, R. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-08-15

    This was a collaborative effort between Lawrence Livermore National Security, LLC as manager and operator of Lawrence Livermore National Laboratory (LLNL) and ISOFLEX USA (ISOFLEX), to 1) develop and test a prototype waste destruction system ("System") using AC plasma torch technology to break down and drastically reduce the volume of Carbon-14 (C-14) contaminated medical laboratory wastes while satisfying all environmental regulations, and 2) develop and demonstrate methods for recovering 99%+ of the carbon including the C-14 allowing for possible re-use as a tagging and labeling tool in the biomedical industry.

  17. Carbon-14 urea breath test for the diagnosis of Campylobacter pylori associated gastritis

    International Nuclear Information System (INIS)

    Marshall, B.J.; Surveyor, I.

    1988-01-01

    Urease in the human gastric mucosa is a marker for infection with Campylobacter pylori (CP), an organism suspected of causing chronic gastritis and peptic ulceration. To detect gastric urease, we examined 32 patients who were being evaluated for possible peptic ulcer disease. Fasting patients were given 10 microCi (370 kBq) of 14 C-labeled urea. Breath samples were collected in hyamine at intervals between 1 and 30 min. The amount of 14 C collected at these times was expressed as: body weight X (% of administered dose of 14 C in sample)/(mmol of CO 2 collected). The presence of C. pylori colonization was also determined by examination of multiple endoscopic gastric biopsy specimens. On average, patients who were proven to have C. pylori infection exhaled 20 times more labeled CO 2 than patients who were not infected. The difference between infected patients and C. pylori negative control patients was highly significant at all time points between 2 and 30 min after ingestion of the radionuclide (p less than 0.0001). The noninvasive urea breath is less expensive than endoscopic biopsy of the stomach and more accurate than serology as a means of detecting Campylobacter pylori infection. Because the test detects actual viable CP organisms, it can be used to confirm eradication of the bacterium after antibacterial therapy

  18. Discharge runaway in high power impulse magnetron sputtering of carbon: the effect of gas pressure, composition and target peak voltage

    Science.gov (United States)

    Vitelaru, Catalin; Aijaz, Asim; Constantina Parau, Anca; Kiss, Adrian Emil; Sobetkii, Arcadie; Kubart, Tomas

    2018-04-01

    Pressure and target voltage driven discharge runaway from low to high discharge current density regimes in high power impulse magnetron sputtering of carbon is investigated. The main purpose is to provide a meaningful insight of the discharge dynamics, with the ultimate goal to establish a correlation between discharge properties and process parameters to control the film growth. This is achieved by examining a wide range of pressures (2–20 mTorr) and target voltages (700–850 V) and measuring ion saturation current density at the substrate position. We show that the minimum plasma impedance is an important parameter identifying the discharge transition as well as establishing a stable operating condition. Using the formalism of generalized recycling model, we introduce a new parameter, ‘recycling ratio’, to quantify the process gas recycling for specific process conditions. The model takes into account the ion flux to the target, the amount of gas available, and the amount of gas required for sustaining the discharge. We show that this parameter describes the relation between the gas recycling and the discharge current density. As a test case, we discuss the pressure and voltage driven transitions by changing the gas composition when adding Ne into the discharge. We propose that standard Ar HiPIMS discharges operated with significant gas recycling do not require Ne to increase the carbon ionization.

  19. Carbon Nanotube and Nanofiber Exposure Assessments: An Analysis of 14 Site Visits

    Science.gov (United States)

    Dahm, Matthew M.; Schubauer-Berigan, Mary K.; Evans, Douglas E.; Birch, M. Eileen; Fernback, Joseph E.; Deddens, James A.

    2015-01-01

    Recent evidence has suggested the potential for wide-ranging health effects that could result from exposure to carbon nanotubes (CNT) and carbon nanofibers (CNF). In response, the National Institute for Occupational Safety and Health (NIOSH) set a recommended exposure limit (REL) for CNT and CNF: 1 µg m−3 as an 8-h time weighted average (TWA) of elemental carbon (EC) for the respirable size fraction. The purpose of this study was to conduct an industrywide exposure assessment among US CNT and CNF manufacturers and users. Fourteen total sites were visited to assess exposures to CNT (13 sites) and CNF (1 site). Personal breathing zone (PBZ) and area samples were collected for both the inhalable and respirable mass concentration of EC, using NIOSH Method 5040. Inhalable PBZ samples were collected at nine sites while at the remaining five sites both respirable and inhalable PBZ samples were collected side-by-side. Transmission electron microscopy (TEM) PBZ and area samples were also collected at the inhalable size fraction and analyzed to quantify and size CNT and CNF agglomerate and fibrous exposures. Respirable EC PBZ concentrations ranged from 0.02 to 2.94 µg m−3 with a geometric mean (GM) of 0.34 µg m−3 and an 8-h TWA of 0.16 µg m−3. PBZ samples at the inhalable size fraction for EC ranged from 0.01 to 79.57 µg m−3 with a GM of 1.21 µg m−3. PBZ samples analyzed by TEM showed concentrations ranging from 0.0001 to 1.613 CNT or CNF-structures per cm3 with a GM of 0.008 and an 8-h TWA concentration of 0.003. The most common CNT structure sizes were found to be larger agglomerates in the 2–5 µm range as well as agglomerates >5 µm. A statistically significant correlation was observed between the inhalable samples for the mass of EC and structure counts by TEM (Spearman ρ = 0.39, P 1 μg m−3. Until more information is known about health effects associated with larger agglomerates, it seems prudent to assess worker exposure to airborne CNT and CNF

  20. 14C dating of freshwater carbonate sediments with special reference to calcareous tufas and laminated lake sediments

    International Nuclear Information System (INIS)

    Pazdur, M.F.

    1992-09-01

    The sequence of laminated sediment of the lake Gosciaz, Poland, covers more than 13,000 years and is actually the longest sequence known so far. Besides of reconstructing past environmental changes, this sequence offers an excellent possibility for studying natural C-14 variations and calibrating the C-14 time scale in a range beyond 6,000 years B.P. The floating varve chronology based on previously taken sediment cores which cover a period of 9,682 years, has been improved by this study. Relative water level changes of the lake during the past 11,500 years have been reconstructed by means of C-14 and C-13 measurements carried out on carbonate fractions of the lake sediments. Periodical variations in the width of annual layers were found. The periods identified are 11 years and 22 years (solar cycle), 35 years (Bruckner cycle), and 200 years. The ratio of summer layer width and the total width of the annual layer shows secular changes which correlate with paleotemperature records. The duration of the Younger Dryas period was determined by combining the floating varve chronology with isotope and pollen analyses of the sediment material. A value of 1,500 years was found. The study also included radiocarbon dating of calcareous tufa taken from different study areas. 26 refs, 26 figs, 6 tabs

  1. Carbon-14 immobilization via the Ba(OH)28H2O process

    International Nuclear Information System (INIS)

    Haag, G.L.; Nehls, J.W. Jr.; Young, G.C.

    1982-01-01

    The airborne release of 14 C from various nuclear facilities has been identified as a potential biohazard due to the long half-life of 14 C (5730 yrs) and the ease in which it may be assimilated into the biosphere. At Oak Ridge National Laboratory, technology is under development, as part of the Airborne Waste Management Program, for the removal and immobilization of this radionuclide. Prior studies have indicated that the 14 C will likely exist in the oxidized form as CO 2 and will contribute slightly to the bulk CO 2 concentration of the gas stream, which is airlike in nature (approx. 330 ppMv CO 2 ). The technology under development utilizes the CO 2 - Ba(OH) 2 8H 2 O gas-solid reaction with the mode of gas-solid contacting being a fixed bed. The product, BaCO 3 , possessing excellent thermal and chemical stability, prerequisites for the long-term disposal of nuclear wastes. For optimal process operation, studies have indicated that an operating window of adequate size does exist. When operating within the window, high CO 2 removal efficiency (effluent concentrations 99%), and an acceptable pressure drop across the bed (3 kPa/m at 13 cm/s superficial velocity) are possible. This paper will address three areas of experimental investigation. These areas are (1) micro-scale studies on 150-mg samples to provide information concerning surface properties, kinetics, and equilibrium vapor pressures, (2) macro-scale studies on large fixed beds (4.2 kg reactant) to determine the effects of humidity, temperature, and gas flow-rate upon bed pressure drop and CO 2 breakthrough, and (3) the design, construction, and initial operation of a pilot unit capable of continuously processing a 34 m 3 /h (20 ft 3 /min) air-based gas stream

  2. Age determination of ground-waters by means of carbon 14

    International Nuclear Information System (INIS)

    Eichinger, L.

    1982-02-01

    At present the age determination of ground-waters aged between 1,500 and approximately 40,000 years is only possible by measuring their 14 C content. A precise age assignment can be established in slightly mineralised waters, whereas it becomes vague in mineralised waters, particularly in acidulous springs. In general, additional information and data are required about the 13 C, D, 18 O, 3 H, 85 Kr and the 39 Ar contents, about the ph value, temperature and the principal ions. (DG) [de

  3. Selected radionuclides. Tritium, carbon-14, krypton-85, strontium-90, iodine, caesium 137, radon, plutonium

    International Nuclear Information System (INIS)

    1983-01-01

    The release of radioactive materials to the environment potentially exposes populations to ionizing radiation and increases the risk of incurring deleterious health effects. The associations of released amounts to effects establish the health criteria for radionuclides. This report provides background information in establishing such health criteria for 14 C, 85 Kr, 90 Sr, 137 Cs, Radon, Plutonium, Iodine and Tritium, including environmental behaviour, sources, transport to man and dosimetry. A brief summary of the general aspects of radiation effects and of radiation protection considerations is presented

  4. The sustainability challenge of meeting carbon dioxide targets in Europe by 2020

    International Nuclear Information System (INIS)

    Saikku, Laura; Rautiainen, Aapo; Kauppi, Pekka E.

    2008-01-01

    Following the Kyoto Protocol, the European Union obligated itself to lower its greenhouse gas (GHG) emissions 20% below their 1990 level, by the year 2020. Carbon dioxide is the major GHG. To fulfil this obligation, the nations must meet the sustainability challenge of countering rising population plus affluence with the dematerialization of less energy per GDP plus the decarbonization of less carbon per energy. To test the feasibility of meeting the challenge, we analysed carbon dioxide emission during 1993-2004. Although emissions in the entire Union grew only by an average of 0.31% per year, emissions and their drivers varied markedly among the 27 member states. Dematerialization and decarbonization did occur, but not enough to offset the slight population growth plus rapidly increasing affluence. To fulfil its obligation in the next 12 years, the EU27 would have to counter its increasing population and affluence by a combined dematerialization and decarbonization 1.9-2.6 times faster than during 1993-2004. Hence, fulfilling its obligation by addressing fossil carbon emissions alone is very unlikely. (author)

  5. The sustainability challenge of meeting carbon dioxide targets in Europe by 2020

    Energy Technology Data Exchange (ETDEWEB)

    Saikku, Laura; Rautiainen, Aapo; Kauppi, Pekka E. [Department of Biological and Environmental Sciences, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki (Finland)

    2008-02-15

    Following the Kyoto Protocol, the European Union obligated itself to lower its greenhouse gas (GHG) emissions 20% below their 1990 level, by the year 2020. Carbon dioxide is the major GHG. To fulfil this obligation, the nations must meet the sustainability challenge of countering rising population plus affluence with the dematerialization of less energy per GDP plus the decarbonization of less carbon per energy. To test the feasibility of meeting the challenge, we analysed carbon dioxide emission during 1993-2004. Although emissions in the entire Union grew only by an average of 0.31% per year, emissions and their drivers varied markedly among the 27 member states. Dematerialization and decarbonization did occur, but not enough to offset the slight population growth plus rapidly increasing affluence. To fulfil its obligation in the next 12 years, the EU27 would have to counter its increasing population and affluence by a combined dematerialization and decarbonization 1.9-2.6 times faster than during 1993-2004. Hence, fulfilling its obligation by addressing fossil carbon emissions alone is very unlikely. (author)

  6. Gastric hyperplasia in mice with targeted disruption of the carbonic anhydrase gene Car9

    Czech Academy of Sciences Publication Activity Database

    Ortova-Gut, M.; Parkkila, S.; Vernerová, Z.; Rohde, E.; Závada, Jan; Hocker, M.; Pastorek, J.; Karttunen, T.; Gibadulinová, A.; Závadová, Zuzana; Knobeloch, K.-P.; Wiedernmann, B.; Svoboda, Jan; Horak, I.; Pastoreková, S.

    2002-01-01

    Roč. 123, č. 6 (2002), s. 1889-1903 ISSN 0016-5085 R&D Projects: GA ČR GV312/96/K205 Institutional research plan: CEZ:AV0Z5052915 Keywords : mouse carbonic anhydrase Car9 * gastric hyperplasia Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 13.440, year: 2002

  7. Gastric Hyperplasia in Mice With Targeted Disruption of the Carbonic Anhydrase Gene Car9

    Czech Academy of Sciences Publication Activity Database

    Ortova Gut, M.; Parkkila, S.; Vernerová, Z.; Rohde, E.; Závada, Jan; Höcker, M.; Pastorek, J.; Karttunen, T.; Gibadulinová, G.; Závadová, Zuzana; Knobeloch, K. P.; Wiedenmann, B.; Svoboda, Jan; Horak, I.; Pastoreková, S.

    2002-01-01

    Roč. 123, č. 12 (2002), s. 1889-1903 ISSN 0016-5085 R&D Projects: GA ČR GV312/96/K205 Keywords : Carbonic Anhydrases * Knock-aou * Differantiation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 13.440, year: 2002

  8. Automatic counting and recording unit used for dating by the carbon 14 method; Ensemble de comptage et d'impression automatique utilise pour la datation par la methode du carbone 14

    Energy Technology Data Exchange (ETDEWEB)

    Albertinoli, P; Galliot, J; Thommeret, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Centre Scientifique de Monaco, Monte Carlo

    1969-07-01

    A description is given of the unit used by the 'Centre Scientifique de Monaco' for low-level beta counting and fitted for radioactive dating by the Carbon 14 method. Built entirely by the laboratory in 1964, on the basis of electronic techniques then recent, it has worked without failure since that time. The proportional counter, its high-voltage negative supply, and the counting chains with visual and printing records are detailed by means of 38 figures which reproduce the counter and the electronic circuits. These are contained in two standard 5 U.I structures. The low-voltage power supply of the whole unit is carried out by plus 12 volts and minus 12 volts storage batteries, buffered on a charger connected on the 110 V alternative line. The proportional counter described is filled with CO{sub 2} under one atmosphere pressure and permits the dating of carbonaceous samples with a maximum of 30.000 + 1.000 years (background 3.96 c.p.m. ) within a moderate time (72 hours). (authors) [French] L'ensemble de comptage pour radioactivite beta a bas niveau, destine a la datation par la methode du carbone 14, utilise au Centre Scientifique de Monaco, est decrit. Entierement construit au laboratoire en 1964, sur la base de techniques electroniques alors recentes, il fonctionne depuis cette date sans defaillance. Le compteur proportionnel, son alimentation haute tension negative et les chaines de comptage transistorisees a affichage et impression sont detailles par 38 schemas reproduisant le compteur et les divers circuits electroniques. Ceux-ci sont contenus dans deux chassis standard 5 UI. L'alimentation basse tension de l'ensemble est obtenue par batteries plus 12 et moins 12 volts montees en tampon sur chargeur alimente par le reseau. Le compteur proportionnel decrit, rempli de CO2 sous une atmosphere, permet de dater les echantillons carbones avec un maximum de 30.000 + 1.000 ans (bruit de fond: 3,96 c.p.m. ) en un temps raisonnable (72 heures). (auteur)

  9. Accidental Carbon Monoxide Poisonings in Adana, Turkey: A 14-year Study

    Directory of Open Access Journals (Sweden)

    Murat Darçın

    2017-03-01

    Full Text Available Aim: Carbon monoxide (CO is often referred to as the “silent killer” because its victims cannot see it, smell it or taste it. CO is responsible for a large percentage of the accidental poisonings and deaths reported throughout the world. CO poisoning therefore is considered a serious global health threat. The aim of the present study was to describe the cases of CO poisoning in a rural areas of Adana, Turkey between 2002 and 2015 based on data collected from incident reports. Methods: The cases of accidental CO poisoning were statistically analyzed. During that period, 74 incidents occurred and 154 people were poisoned by accidental CO poisoning. Results: The results of this analysis indicate that men and adults aged ≥65 years were more likely to die from CO poisoning than others. The number of CO poisoning cases was highest during the heating season. The majority (72% of poisoning resulting in hospitalization with a life-threatening condition or death occurred within the home. Conclusion: CO poisoning is a serious danger. People must be informed about this hazard. By educating risk groups about the dangers of CO poisoning, it is possible to save many lives as well as reduce the health risks.

  10. Influence of a carbamate pesticide on growth, respiration (/sup 14/C)-carbon metabolism and symbiosis of a Rhizobium sp

    Energy Technology Data Exchange (ETDEWEB)

    Sekar, T; Balasubramanian, A [Tamil Nadu Agricultural Univ., Coimbatore (India)

    1979-04-01

    Addition of aldicarb (2 methyl-2(methyl thio) propionaldehyde-O-methyl carbamoyl oxime) in the growth medium enhanced the growth of Rhizobium sp. (cowpea group) at 2ppm level while an inhibition was observed at the normal (5 ppm) and higher (10 ppm) concentrations. Respiration of the cells was also inhibited by 5 and 10 ppm levels of the chemical eventhough a stimulation was observed at 2 ppm (lower) concentration. The insecticide, when incorporated at 5 and 10 ppm levels in the medium increased the /sup 14/C-glucose incorporation and considerably altered the assimilation of the radioactive carbon in different fractions of rhizobium cells. Soil application of this insecticide (Temik 10 G) reduced the number of nodules formed and the total nitrogen content in cowpea plants inoculated with the Rhizobium sp. but enhanced the dry matter production of cowpea plants.

  11. Investigation on the distribution of tritium and carbon-14 in the amino acids of labelled green algae (Scenedesmus Quadricauda ssp.)

    International Nuclear Information System (INIS)

    Nuernberger, E.; Clausen, E.; Kistner, G.

    1982-01-01

    Green algae (Scenedesmus quadricauda ssp. subspicatus), labelled twice tritium and carbon-14, showed an incorporation of nuclides into the cell mass of 0.02% and 95%, respectively. The distribution of radioactivity in the individual amino acids was examined in a protein fraction with special emphasis on the essential amino acids in view of their following incorporation into the next link of the aquatic food chain (Daphnia). The highest values were found in glutamine and asparagine acids as well as in the essential amino acids leucine and arginine, which are amino acids with a relatively high amount of non exchangeable H-positions per molecule and, therefore, a relatively high and stable labelling. (author)

  12. Utilization of [1-14C]carbon of glycine of high glycine diet fed young and old rats

    International Nuclear Information System (INIS)

    Petzke, K.J.; Albrecht, V.; Medovar, B.Ya.; Pisarczuk, K.L.; Grigorov, Yu.G.

    1987-01-01

    The incorporation of radioactivity from [1- 14 C]glycine was studied in various organ (serum, liver, muscle) fractions (acid soluble, proteins, lipids, liver glycogen) and carbon dioxide in rats fed with isonitrogenous isocaloric purfied diets. The diets contained 30% casein (control), gelatin (exchange of half of the 30% casein) or glycine (corresponding level of glycine in relation to the gelatin diet). The incorporation of radioactivity into proteins was reduced by feeding high glycine diets in young (20-weeks-old) and old (18-month-old) rats in relation to the control diet. The modifications of the results for old animals may be partially explained on the base of a reduced protein turnover rate and adaptation to a high gelatin (glycine) diet. (author)

  13. Incorporation of 14C glucose into glycogen and glucose-6-phosphate dehydrogenase activity in rat brain following carbon monoxide intoxication

    International Nuclear Information System (INIS)

    Sikorska, M.; Gorzkowski, B.; Szumanska, G.; Smialek, M.

    1975-01-01

    Incorporation of 14 C glucose into glycogen and glucose-6-phosphate dehydrogenase activity in rat brain following carbon monoxide intoxication was studied. In brains of rats tested on the 20, 30 and 60th minute of exposure to CO and immediately after removal from the chamber the enzyme activity showed no essential deviation from the control level. In the group of rats tested 1 hour after taking them out from the chamber increase of the enzyme activity was noticed, amounting to about 33% of the control value. The brains tested 24 hours after exposure showed the largest increase of the enzyme activity by about 94%. In the next time periods, 48 and 72 hours after intoxication, the enzyme activity was decreasing. The glycogen content in brains of control animals increased 3 hours after CO intoxication by about 69%. The increase of glycogen synthesis was expressed by increase of the total radioactivity, which amounted to 160% of the control value. (Z.M.)

  14. The rates of carbon cycling in several soils from AMS14C measurements of fractionated soil organic matter

    International Nuclear Information System (INIS)

    Trumbore, S.E.; Bonani, G.; Wolfli, W.

    1990-01-01

    14 C mean residence times (MRT) of fractionated organic matter are reported for three pre-bomb soil profiles. Comparisons of organic matter extracted with acid and base showed that the longest MRTs were associated with the non-acid-hydrolysable fraction. The MRT of organic matter in a soil layer represents a combination of the rates of several processes, including decay to CO 2 and transport out of the layer. In some instances (notably in the A horizon of the Podzol soil studied in this paper), the MRT is dominated by the rate of transport, rather than the rate of decay. Thus it is important to use the distribution and balance of carbon in the soil profile to assess the meaning of the MRT with respect to influencing atmospheric CO 2

  15. Interactions between 59Fe(14C)EDTA and soils containing calcium carbonate

    International Nuclear Information System (INIS)

    Hargitai-Toth, A.; Konya, J.

    1991-01-01

    Interaction between FeEDTA and calcareous soils was followed over a period of four weeks using a radiotracer technique, and a kinetic evaluation of the results was performed. 59 Fe served to determine the quantity of iron, 14 C to assay for EDTA and 45 Ca to measure calcium. During the experiment, i.e. within four weeks in case of the chernozem soil 61% and in case of the clayey meadow soil 51% of the iron chelate disappeared from the solution. The loss in soluble iron was partly due to a rapid sorption process of about an hour and partly due to the slow decomposition of FeEDTA to Fe(OH) 3 . The two processes could be separated using the Christiansen equation. (author) 9 refs.; 1 figs.; 2 tabs

  16. Extraction of carbon 14-labeled compounds from plant tissue during processing for electron microscopy

    International Nuclear Information System (INIS)

    Coetzee, J.; van der Merwe, C.F.

    1989-01-01

    Loss of 14 C-labeled compounds from bean leaf tissue was monitored during all the stages of routine specimen preparation. No significant differences in extraction were associated with the use of acetone, ethanol, or dioxane as dehydration fluids. Fixation at low temperature increased the loss of label. Prolonged fixation in glutaraldehyde increased the loss, but fixation in osmium solutions for periods as long as 4 hr had no influence on extraction. Buffer rinses and dehydration fluids caused appreciable amounts of label to be extracted. The use of propylene oxide as transition fluid resulted in low extraction. Some embedding media caused the loss of small amounts of labeled compounds, but one of the media tested (LR-white) extracted significant amounts of label

  17. Carbon-14 immobilization via the Ba(OH)2.8H2O process

    International Nuclear Information System (INIS)

    Haag, G.L.; Nehls, J.W. Jr.; Young, G.C.

    1983-03-01

    The airborne release of 4 C from varous nuclear facilities has been identified as a potential biohazard due to the long half-life of 14 C (5730 y) and the ease with which it may be assimilated into the biosphere. At ORNL, technology has been developed for the removal and immobilization of this radionuclide. Prior studies have indicated that 14 C will likely exist in the oxidized form as CO 2 and will contribute slightly to the bulk CO 2 concentration of the gas stream, which is airlike in nature (approx. 330 ppmv CO 2 ). The technology that has been developed utilizes the CO 2 -Ba(OH) 2 .8H 2 O gas-solid reaction with the mode of gas-solid contacting being a fixed bed. The product, BaCO 3 , possesses excellent thermal and chemical stability, prerequisites for the long-term disposal of nuclear wastes. For optimal process operation, studies have indicated that an operating window of adequate size does exist. When operating within the window, high CO 2 removal efficiency (effluent concentrations 99%), and an acceptable pressure drop across the bed (3 kPa/m at a superficial velocity of 13 cm/s) are possible. This paper addresses three areas of experimental investigation: (1) microscale studies on 150-mg samples to provide information concerning surface properties, kinetics, and equilibrium vapor pressures; (2) macroscale studies on large fixed beds (4.2 kg of reactant) to determine the effects of humidity, temperature, and gas flow rate upon bed pressure drop and CO 2 breakthrough; and (3) design, construction, and initial operation of a pilot unit capable of continuously processing a 34-m 3 /h (20-ft 3 /min) air-based gas stream

  18. Partitioning sources of recharge in environments with groundwater recirculation using carbon-14 and CFC-12

    Science.gov (United States)

    Bourke, Sarah A.; Cook, Peter G.; Dogramaci, Shawan; Kipfer, Rolf

    2015-06-01

    Groundwater recirculation occurs when groundwater is pumped from an aquifer onto the land surface, and a portion of that water subsequently infiltrates back to the aquifer. In environments where groundwater is recirculated, differentiation between various sources of recharge (e.g. natural rainfall recharge vs. recirculated water) can be difficult. Groundwater age indicators, in particular transient trace gases, are likely to be more sensitive tracers of recharge than stable isotopes or chloride in this setting. This is because, unlike stable isotopes or chloride, they undergo a process of equilibration with the atmosphere, and historical atmospheric concentrations are known. In this paper, groundwater age indicators (14C and CFC-12) were used as tracers of recharge by surplus mine water that is discharged to streams. Ternary mixing ratios were calculated based on 14C and CFC-12 concentrations measured along three transects of piezometers and monitoring wells perpendicular to the creeks, and from dewatering wells. Uncertainty in calculated mixing ratios was estimated using a Monte Carlo approach. Ternary mixing ratios in dewatering wells suggest that recharge by mine water accounted for between 10% and 87% of water currently abstracted by dewatering wells. The calculated mixing ratios suggest that recharge by mine water extends to a distance of more than 550 m from the creeks. These results are supported by seepage flux estimates based on the water and chloride balance along the creeks, which suggest that 85-90% of mine water discharged to the creeks recharges the aquifer and recharge by mine water extends between 110 and 730 m from the creeks. Mixing calculations based on gaseous groundwater age indicators could also be used to partition recharge associated with agricultural irrigation or artificial wetland supplementation.

  19. Preliminary study of lead isotopes in the carbonate-silica veins of Trench 14, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Zartman, R.E.; Kwak, L.M.

    1993-01-01

    The sub-vertical carbonate-silica veins filling the Bow Ridge Fault, where exposed in Trench 14 on the east side of Yucca Mountain, carry a lead isotopic signature that can be explained in terms of local sources. Two isotopically distinguishable--silicate and carbonate--fractions of lead are recognized within the vein system as well as in overlying surficial calcrete deposits. The acid-insoluble silicate fraction is contributed largely from the decomposing Miocene volcanic tuff, which forms the wall rock of the fault zone and is a ubiquitous component of the overlying soil. Lead contained in the silicate fraction approaches in isotopic composition that of the Miocene volcanic rocks of Yucca Mountain, but diverges from it in some samples by being more enriched in uranogenic isotopes. The carbonate fraction of lead in both vein and calcrete samples resides dominantly in the HCl- and CH 3 COOH-soluble calcite. HCl evidently also attacks and removes lead from silicate phases, but the milder CH 3 COOH dissolution procedure oftentimes identifies a significantly more radiogenic lead in the calcite. Wind-blown particulate matter brought to the area from Paleozoic and Late Proterozoic limestones in surrounding mountains may be the ultimate source of the calcite. Isotopically more uniform samples suggest that locally the basaltic ash and other volcanic rock have contributed most of the lead to both fractions of the vein system. An important finding of this study is that the data does not require the more exotic mechanisms or origins that have been proposed for the veins. Instead, the remarkably similar lead isotopic properties of the veins to those of the soil calcretes support their interpretation as a surficial, pedogenic phenomenon

  20. Direct growth and patterning of multilayer graphene onto a targeted substrate without an external carbon source.

    Science.gov (United States)

    Kang, Dongseok; Kim, Won-Jun; Lim, Jung Ah; Song, Yong-Won

    2012-07-25

    Using only a simple tube furnace, we demonstrate the synthesis of patterned graphene directly on a designed substrate without the need for an external carbon source. Carbon atoms are absorbed onto Ni evaporator sources as impurities, and incorporated into catalyst layers during the deposition. Heat treatment conditions were optimized so that the atoms diffused out along the grain boundaries to form nanocrystals at the catalyst-substrate interfaces. Graphene patterns were obtained under patterned catalysts, which restricted graphene formation to within patterned areas. The resultant multilayer graphene was characterized by Raman spectroscopy and transmission electron microscopy to verify the high crystallinity and two-dimensional nanomorphology. Finally, a metal-semiconductor diode with a catalyst-graphene contact structure were fabricated and characterized to assess the semiconducting properties of the graphene sheets with respect to the display of asymmetric current-voltage behavior.

  1. Focus on cumulative emissions, global carbon budgets and the implications for climate mitigation targets

    Science.gov (United States)

    Damon Matthews, H.; Zickfeld, Kirsten; Knutti, Reto; Allen, Myles R.

    2018-01-01

    The Environmental Research Letters focus issue on ‘Cumulative Emissions, Global Carbon Budgets and the Implications for Climate Mitigation Targets’ was launched in 2015 to highlight the emerging science of the climate response to cumulative emissions, and how this can inform efforts to decrease emissions fast enough to avoid dangerous climate impacts. The 22 research articles published represent a fantastic snapshot of the state-or-the-art in this field, covering both the science and policy aspects of cumulative emissions and carbon budget research. In this Review and Synthesis, we summarize the findings published in this focus issue, outline some suggestions for ongoing research needs, and present our assessment of the implications of this research for ongoing efforts to meet the goals of the Paris climate agreement.

  2. Mamizu climate policy: an evaluation of Japanese carbon emissions reduction targets

    International Nuclear Information System (INIS)

    Pielke, Roger A Jr

    2009-01-01

    This letter evaluates Japan's so-called 'Mamizu' climate policies proposed in mid-2009 in terms of the implied rates of decarbonization of the Japanese economy for short-term and long-term targets. The letter uses the Kaya identity to structure the evaluation, employing both a bottom up approach (based on projections of future Japanese population, economic growth, and technology) and a top down approach (deriving implied rates of decarbonization consistent with the targets and various rates of economic growth). Both approaches indicate that the Japanese economy would have to achieve rates of decarbonization of 2.6% to meet a 2020 target of reducing emissions by 15% below 2005 levels, and 5.0% to meet a 2050 target of an 80% reduction below 2005 levels. A target of 25% below 1990 emissions proposed by the opposition party (which subsequently formed a government following elections in August 2009) implies a rate of decarbonization of 4.6% annually to 2020. The letter argues that international criticism of Japanese Mamizu climate policy proposals as being too weak was unfounded, and if anything, the proposals may have been too ambitious. In either case, climate policy would be strengthened through the support of a diversity of approaches to decarbonization.

  3. Synthesis of organic substances labelled with {sup 14}C and {sup 35}S; Syntheses de molecules organiques marquees par le carbone-14 et le soufre-35

    Energy Technology Data Exchange (ETDEWEB)

    Pichat, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    After a brief history of the development of the Section des Molecules marquees of the Frenchmic Energy Commission, the author gives an outline of the synthesis of the following labelled compounds: benzene {sup 14}C-6; phenyl-p-fluorophenyl, thienyl-2 {beta} alanines {beta} {sup 14}C; noradrenaline {beta} {sup 14}C (arterenol {beta} {sup 14}C), dotriacontane {sup 14}C-16-17, aminoethane sulfinic acid (hypotaurine {sup 35}S). (author)Fren. [French] Apres un bref historique du developpement de la Section des Molecules marquees du Commissariat a l'Energie Atomique fran is, l'auteur donne un resume des syntheses des composes marques suivants: benzene {sup 14}C-6; phenyl-p-fluorophenyl, thienyl-2 {beta} alamines {beta} {sup 14}C; noradrenaline {beta} {sup 14}C (arterenol {beta} {sup 14}C), dotriacontane {sup 14}C-16-17, acide aminoethane sulfinique (hypotaurine {sup 35}S). (auteur)

  4. Catalytic hydrogenation of carbon monoxide. Progress report, December 15, 1991--December 14, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  5. Hexon and fiber of adenovirus type 14 and 55 are major targets of neutralizing antibody but only fiber-specific antibody contributes to cross-neutralizing activity.

    Science.gov (United States)

    Feng, Ying; Sun, Xikui; Ye, Xianmiao; Feng, Yupeng; Wang, Jinlin; Zheng, Xuehua; Liu, Xinglong; Yi, Changhua; Hao, Mingli; Wang, Qian; Li, Feng; Xu, Wei; Li, Liang; Li, Chufang; Zhou, Rong; Chen, Ling; Feng, Liqiang

    2018-05-01

    Re-emerging human adenoviruses type 14 (HAdV14) and 55 (HAdV55) represent two highly virulent adenoviruses. The neutralizing antibody (nAb) responses elicited by infection or immunization remain largely unknown. Herein, we generated hexon-chimeric HAdV14 viruses harboring each single or entire hexon hyper-variable-regions (HVR) from HAdV55, and determined the neutralizing epitopes of human and mouse nAbs. In human sera, hexon-targeting nAbs are type-specific and mainly recognize HVR2, 5, and 7. Fiber-targeting nAbs are only detectable in sera cross-neutralizing HAdV14 and HAdV55 and contribute substantially to cross-neutralization. Penton-binding antibodies, however, show no significant neutralizing activities. In mice immunized with HAdV14 or HAdV55, a single immunization mainly elicited hexon-specific nAbs, which recognized HAdV14 HVR1, 2, and 7 and HAdV55 HVR1 and 2, respectively. After a booster immunization, cross-neutralizing fiber-specific nAbs became detectable. These results indicated that hexon elicits type-specific nAbs whereas fiber induces cross-neutralizing nAbs to HAdV14 and HAdV55, which are of significance in vaccine development. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Chemical investigations of isotope separation on line target units for carbon and nitrogen beams

    CERN Document Server

    Franberg, H; Gäggeler, H W; Köster, U

    2006-01-01

    Radioactive ion beams (RIBs) are of significant interest in a number of applications. Isotope separation on line (ISOL) facilities provide RIB with high beam intensities and good beam quality. An atom that is produced within the ISOL target will first diffuse out from the target material. During the effusion towards the transfer line and into the ion source the many contacts with the surrounding surfaces may cause unacceptable delays in the transport and, hence, losses of the shorter-lived isotopes. We performed systematic chemical investigations of adsorption in a temperature and concentration regime relevant for ISOL targets and ion source units, with regard to CO/sub x/ and NOmaterials are potential construction materials for the above-mentioned areas. Off-line and on-line tests have been performed using a gas thermochromatography setup with radioactive tracers. The experiments were performed at the production of tracers for atmospheric chemistry (PROTRAC) facility at the Paul Schener Institute in Villigen...

  7. Targeted delivery and controlled release of Paclitaxel for the treatment of lung cancer using single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Yu, Baodan; Tan, Li; Zheng, Runhui; Tan, Huo; Zheng, Lixia

    2016-01-01

    A new type of drug delivery system (DDS) based on single-walled carbon nanotubes (SWNTs) for controlled-release of the anti-cancer drug Paclitaxel (PTX) was constructed in this study. Chitosan (CHI) was non-covalently attached to the SWNTs to improve biocompatibility. Biocompatible hyaluronan was also combined to the outer CHI layer to realise the specific targeting property. The results showed that the release of PTX was pH-triggered and was better at lower pH (pH 5.5). The modified SWNTs showed a significant improvement in intracellular reactive oxygen species (ROS), which may have enhanced mitogen-activated protein kinase activation and further promoted cell apoptosis. The results of western blotting indicated that the apoptosis-related proteins were abundantly expressed in A549 cells. Lactate dehydrogenase (LDH) release assay and cell viability assay demonstrated that PTX-loaded SWNTs could destroy cell membrane integrity, thus inducing lower cell viability of the A549 cells. Thus, this targeting DDS could effectively inhibit cell proliferation and kill A549 cells, is a promising system for cancer therapy. - Highlights: • Chitosan and hyaluronan modified single-walled carbon nanotubes (SWNTs) were prepared for delivery of Paclitaxel (PTX). • Morphology, drug loading efficiency and drug release amount of the nanotubes were studied. • Cell viability, LDH, intracellular ROS levels and western blotting were evaluated. • The drug delivery system could effectively inhibit A549 cells proliferation.

  8. Targeted delivery and controlled release of Paclitaxel for the treatment of lung cancer using single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Baodan; Tan, Li; Zheng, Runhui; Tan, Huo, E-mail: tanhuo.2008@163.com; Zheng, Lixia, E-mail: 66593953@qq.com

    2016-11-01

    A new type of drug delivery system (DDS) based on single-walled carbon nanotubes (SWNTs) for controlled-release of the anti-cancer drug Paclitaxel (PTX) was constructed in this study. Chitosan (CHI) was non-covalently attached to the SWNTs to improve biocompatibility. Biocompatible hyaluronan was also combined to the outer CHI layer to realise the specific targeting property. The results showed that the release of PTX was pH-triggered and was better at lower pH (pH 5.5). The modified SWNTs showed a significant improvement in intracellular reactive oxygen species (ROS), which may have enhanced mitogen-activated protein kinase activation and further promoted cell apoptosis. The results of western blotting indicated that the apoptosis-related proteins were abundantly expressed in A549 cells. Lactate dehydrogenase (LDH) release assay and cell viability assay demonstrated that PTX-loaded SWNTs could destroy cell membrane integrity, thus inducing lower cell viability of the A549 cells. Thus, this targeting DDS could effectively inhibit cell proliferation and kill A549 cells, is a promising system for cancer therapy. - Highlights: • Chitosan and hyaluronan modified single-walled carbon nanotubes (SWNTs) were prepared for delivery of Paclitaxel (PTX). • Morphology, drug loading efficiency and drug release amount of the nanotubes were studied. • Cell viability, LDH, intracellular ROS levels and western blotting were evaluated. • The drug delivery system could effectively inhibit A549 cells proliferation.

  9. The synthesis of the insecticides Aldrin and Dieldrin labelled with carbon-14 at high specific activity; Synthese des insecticides aldrine et dieldrine marques au carbone-14 de haute activite specifique; Sintez insektitsidnogo aldrina i dildrina, mechennykh uglerodom-14 pri vysokoj udel'noj aktivnosti; Sintesis de los insecticidas aldrin y dieldrin de elevada actividad especifica marcados con carbono-14

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Daniel J; Kilner, A Edward [Radiochemical Centre, UKAEA, Amersham, Bucks (United Kingdom)

    1962-03-15

    Aldrin is the trade name given by Shell Chemicals to 1, 2, 3, 4, 10, 10-hexachloro-1, 4, 4a, 5, 8, 8a-hexahydro-exo-1, 4-endo-5, 8-dimethanonapthalene. Acetylene-1, 2-C{sup 14} is converted successively to tetrachloroethane and trichloroethylene, and this is condensed with carbon tetrachloride by the Prins reaction in the presence of aluminium chloride to octachlorocyclopentene. Dechlorination gives hexachlorocyclopentadiene which undergoes a Diels-Alder addition to bicyclo(2, 2, 1) hepta-2,5-diene to give aldrin-C{sup 14} in 12% yield from barium carbonate. Oxidation of Aldrin gives the 6,7 epoxide, Dieldrin, in 87% yield. The paper includes an account of the separation of octachlorocyclopentene from the crude product of the Prins reaction by gas-liquid chromatography and of the separation of Aldrin and Dieldrin on a small preparative scale by reversed-phase paper chromatography. (author) [French] Aldrine est la denomination commerciale par laquelle la Shell Chemicals designe l'hexachloro-1, 2, 3, 4, 10, 10-hexahydro-1, 4, 4a, 5, 8, 8a-exo-endo-1,4- dimethano-5, 8-naphtalene. L'acetylene-1,2-C{sup 14} est successivement transforme en terachloroethane et en trichloroethylene, lequel se condense avec le tetrachlorure de carbone, par la reaction de Prins, en presence de chlorure d'aluminium, pour donner de l'octachlorocyclopentene. La dechloruration fournit de l'hexachlorocyclopentadiene, lequel, par une synthese de Diels-Alder, se transforme en bicyclohepta(2, 2, 1)-diene-2, 5 pour donner de l'aldrine-C{sup 14}, avec un rendement de 12% par rapport au carbonate de baryum. L'oxydation de l'aldrine donne l'epoxyde-6 7-(dieldrine), avec un rendement de 87%. Les auteurs decrivent, en outre, la separation de l'octachlorocyclopentene par chromatographie gaz-liquide, a partir du produit brut de la reaction de Prins, ainsi que la separation de l'aldrine et de la dieldrine, en petite quantite, par chromatographie sur papier a phase renversee. (author) [Spanish] Aldrin es el

  10. Study of intermittency of target fragments in the interactions of 28Si-Em collisions at 14.6 A GeV

    International Nuclear Information System (INIS)

    Ayaz Ahmad, M.; Ashraf T, M.; Ahmad, Shafiq

    2008-01-01

    An attempt has been made to investigate the intermittent behaviour and fractal properties of emission spectra of fast and slow target associated particles from 28 Si-emulsion interactions at 14.6 A GeV using nuclear emulsion in cosθ phase space

  11. Reaction dynamics of {sup 34-38}Mg projectile with carbon target using Glauber model

    Energy Technology Data Exchange (ETDEWEB)

    Shama, Mahesh K., E-mail: maheshphy82@gmail.com [School of Physics and Material Sciences, Thapar University Patiala-147004 (India); Department of Applied Sciences, Chandigarh Engineering College, Landran Mohali-140307 (India); Panda, R. N. [Department of Physics, ITER, Shiksha O Anusandhan University, Bhubaneswar-751030 (India); Sharma, Manoj K. [School of Physics and Material Sciences, Thapar University Patiala-147004 (India); Patra, S. K. [Institute of Physics, Sachivalaya marg Bhubneswar-751005 (India)

    2015-08-28

    We have studied nuclear reaction cross-sections for {sup 34-38}Mg isotopes as projectile with {sup 12}C target at projectile energy 240AMeV using Glauber model with the conjunction of densities from relativistic mean filed formalism. We found good agreement with the available experimental data. The halo status of {sup 37}Mg is also investigated.

  12. Reaction cross sections for 8He and 14B on proton target for the separation of proton and neutron density distributions

    International Nuclear Information System (INIS)

    Tanaka, Masaomi; Fukuda, Mitsunori; Nishimura, Daiki

    2015-01-01

    We utilized the proton-neutron asymmetry of nucleon–nucleon total cross sections in the intermediate energy region (σ pn ≠σ pp(nn) ) to obtain the information of proton and neutron distributions respectively. We have measured reaction cross sections (σ R ) for 14 B and 8 He on proton targets as isospin asymmetric targets in addition to symmetric ones. Proton and neutron density distributions were derived respectively through the χ 2 -fitting procedure with the modified Glauber calculation. The result suggests a necessity for 14 B of a long tail, and also a necessity for 8 He of a neutron tail. Root-mean-square proton, neutron and matter radii for 14 B and 8 He are also derived. Each radius is consistent with some of the other experimental values and also with some of the several theoretical values. (author)

  13. BECCS capability of dedicated bioenergy crops under a future land-use scenario targeting net negative carbon emissions

    Science.gov (United States)

    Kato, E.; Yamagata, Y.

    2014-12-01

    Bioenergy with Carbon Capture and Storage (BECCS) is a key component of mitigation strategies in future socio-economic scenarios that aim to keep mean global temperature rise below 2°C above pre-industrial, which would require net negative carbon emissions in the end of the 21st century. Because of the additional need for land, developing sustainable low-carbon scenarios requires careful consideration of the land-use implications of deploying large-scale BECCS. We evaluated the feasibility of the large-scale BECCS in RCP2.6, which is a scenario with net negative emissions aiming to keep the 2°C temperature target, with a top-down analysis of required yields and a bottom-up evaluation of BECCS potential using a process-based global crop model. Land-use change carbon emissions related to the land expansion were examined using a global terrestrial biogeochemical cycle model. Our analysis reveals that first-generation bioenergy crops would not meet the required BECCS of the RCP2.6 scenario even with a high fertilizer and irrigation application. Using second-generation bioenergy crops can marginally fulfill the required BECCS only if a technology of full post-process combustion CO2 capture is deployed with a high fertilizer application in the crop production. If such an assumed technological improvement does not occur in the future, more than doubling the area for bioenergy production for BECCS around 2050 assumed in RCP2.6 would be required, however, such scenarios implicitly induce large-scale land-use changes that would cancel half of the assumed CO2 sequestration by BECCS. Otherwise a conflict of land-use with food production is inevitable.

  14. The triply-ionized carbon forest from eBOSS: cosmological correlations with quasars in SDSS-IV DR14

    Science.gov (United States)

    Blomqvist, Michael; Pieri, Matthew M.; du Mas des Bourboux, Hélion; Busca, Nicolás G.; Slosar, Anže; Bautista, Julian E.; Brinkmann, Jonathan; Brownstein, Joel R.; Dawson, Kyle; de Sainte Agathe, Victoria; Guy, Julien; Percival, Will J.; Pérez-Ràfols, Ignasi; Rich, James; Schneider, Donald P.

    2018-05-01

    We present measurements of the cross-correlation of the triply-ionized carbon (CIV) forest with quasars using Sloan Digital Sky Survey Data Release 14. The study exploits a large sample of new quasars from the first two years of observations by the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). The CIV forest is a weaker tracer of large-scale structure than the Lyα forest, but benefits from being accessible at redshifts zfit to the quasar-CIV cross-correlations for the CIV forest and the SiIV forest, the CIV redshift-space distortion parameter is βCIV=0.27 ‑0.14 ‑0.26 +0.16 +0.34 and its combination with the CIV linear transmission bias parameter is bCIV(1+βCIV)=‑0.0183 ‑0.0014 ‑0.0029 +0.0013 +0.0025 (1σ and 2σ statistical errors) at the mean redshift z=2.00. Splitting the sample at z=2.2 to constrain the bias evolution with redshift yields the power-law exponent γ=0.60±0.63, indicating a significantly weaker redshift-evolution than for the Lyα forest linear transmission bias. Additionally, we demonstrate that CIV absorption has the potential to be used as a probe of baryon acoustic oscillations (BAO). While the current data set is insufficient for a detection of the BAO peak feature, the final quasar samples for redshifts 1.4

  15. Micro-syntheses for the use of carbon 13 or carbon 14. Micro-preparations of methyl alcohol, methyl iodide, and sodium acetate labeled in the methyl group; Microsyntheses pour l'emploi de carbone 13 ou de carbone 14. Micropreparations d'alcool methylique, d'iodure de methyle et d'acetate de sodium marque sur le groupement methyle

    Energy Technology Data Exchange (ETDEWEB)

    Baret, C; Pichat, L

    1951-11-01

    Apparatus and technique are described in detail for (1) reduction of CO{sub 2} to CH{sub 3}OH with LiAlH{sub 4}, (2) conversion of the methanol to CH{sub 3}I by HI, (3) formation of the Mg Grignard reagent, and (4) addition of inactive CO{sub 2} to form CH{sub 3}COOH. All these operations have been carried out on 0.005 moles. Methyl-labeled Na acetate has been prepared in 67% yield based on the Ba{sup 14}CO{sub 3} used as starting material. (author) [French] Description detaillee d'une technique deja connue pour la reduction du gaz carbonique en alcool methylique par LiAlH{sub 4}. Conversion du methanol en iodure de methyle. Ce dernier transforme en reactif de Grigard, et carbonate, fournit de l'acide acetique. Toutes ces operations on ete effectuees sur 5 x 10{sup -3} moles. La methode a ete appliquee a la synthese d'acetate de sodium marque par le groupement methyle par {sup 14}C avec un rendement global de 67% base sur le carbonate de baryum radioactif mis en oeuvre. (auteurs)

  16. Spatial distribution of carbon species in laser ablation of graphite target

    International Nuclear Information System (INIS)

    Ikegami, T.; Ishibashi, S.; Yamagata, Y.; Ebihara, K.; Thareja, R.K.; Narayan, J.

    2001-01-01

    We report on the temporal evolution and spatial distribution of C 2 and C 3 molecules produced by KrF laser ablation of a graphite target using laser induced fluorescence imaging and optical emission spectroscopy. Spatial density profiles of C 2 were measured using two-dimensional fluorescence in various pressures of different ambient (vacuum, nitrogen, oxygen, hydrogen, helium, and argon) gases at various ablation laser fluences and ablation area. A large yield of C 2 is observed in the central part of the plume and near the target surface and its density and distribution was affected by the laser fluence and ambient gas. Fluorescent C 3 was studied in Ar gas and the yield of C 3 is enhanced at higher gas pressure and longer delay times after ablation

  17. Chemical Investigations of ISOL target units for carbon and nitrogen beams

    CERN Document Server

    Franberg, H; Gäggeler, H W; Köster, U

    2006-01-01

    Radioactive Ion Beams (RIB) are of significant interest in a number of applications. ISOL (Isotope Separation On Line) facilities provide RIB with high beam intensities and good beam quality. An atom that is produced within the ISOL target will first diffuse out from the target material. During the effusion towards the transfer line and into the ion source the many contacts with the surrounding surfaces may cause unacceptable delays in the transport and, hence, losses of the shorter-lived isotopes. We performed systematic chemical investigations of adsorption in a temperature and concentration regime relevant for ISOL targets and ion source units, with regard to COx and NOx on Al2O3 and SiO2. These materials are potential construction materials for the above mentioned areas. Off-line and on-line tests have been performed using a gas thermo-chromatography set-up with radioactive tracers. The experiments were performed at the PROTRAC facility at Paul Scherrer Institute in Villigen, Switzerland.

  18. Functionalized single-walled carbon nanotube-based fuel cell benchmarked against US DOE 2017 technical targets.

    Science.gov (United States)

    Jha, Neetu; Ramesh, Palanisamy; Bekyarova, Elena; Tian, Xiaojuan; Wang, Feihu; Itkis, Mikhail E; Haddon, Robert C

    2013-01-01

    Chemically modified single-walled carbon nanotubes (SWNTs) with varying degrees of functionalization were utilized for the fabrication of SWNT thin film catalyst support layers (CSLs) in polymer electrolyte membrane fuel cells (PEMFCs), which were suitable for benchmarking against the US DOE 2017 targets. Use of the optimum level of SWNT -COOH functionality allowed the construction of a prototype SWNT-based PEMFC with total Pt loading of 0.06 mg(Pt)/cm²--well below the value of 0.125 mg(Pt)/cm² set as the US DOE 2017 technical target for total Pt group metals (PGM) loading. This prototype PEMFC also approaches the technical target for the total Pt content per kW of power (<0.125 g(PGM)/kW) at cell potential 0.65 V: a value of 0.15 g(Pt)/kW was achieved at 80°C/22 psig testing conditions, which was further reduced to 0.12 g(Pt)/kW at 35 psig back pressure.

  19. Synthesis of methyl [(chloro-2 ethyl)-3 nitroso-3 Ureido]-3 Didesoxy-2,3 α-D-Arabino-hexopyrannoside labelled with carbon-14 or carbon-13 (CY 233 - SR 90008)

    International Nuclear Information System (INIS)

    Sion, R.; Schumer, A.; Durme, E. van; Gouyette, A.; Geslin, M.; Fournier, J.P.; Roger, P.

    1990-01-01

    CY 233 (Ecomustine or SR 90098) is a new antitumour nitrosourea: it is characterized by a 2-chloroethylnitrosourea substituent on a dideoxycarbohydrate. It has been labelled with 14 C on a) the carbonyl group of the urea in four stages starting with 14 COCl 2 , b) the second carbon of the chloroethyl group in four stages starting with [ 14 C] ethanolamine, and c) on the methyl group on the anomeric centre of the carbohydrate in three stages starting with 14 CH 3 OH. The final position was also labelled with 13 C starting with 13 CH 3 OH. These differently labelled compounds are suitable for mechanistic studies of antitumour activity. (author)

  20. Estimation of radiation dosage and transmutation effect of 14C involved in measuring rate of albumin synthesis with 14C-carbonate

    International Nuclear Information System (INIS)

    Yap, A.H.; Hafkenscheid, J.C.M.; Goossens, C.M.I.C.; Buys, W.C.A.M.; Binkhorst, R.A.; Van Tongeren, J.H.M.

    1975-01-01

    For direct measurement of the rate of albumin synthesis, Na 2 14 CO 3 was used intravenously. The assessment of the radiation hazard involved in the study was based on the knowledge of the minimum dose of Na 2 14 CO 3 necessary for a sufficient incorporation of 14 C in the guanidine-C of arginine in albumin to obtain measurable radioactivity. By measurement of expired 14 CO 2 and excreted 14 C-urea in the urine during a 5-hr period following intravenous administration of Na 2 14 CO 3 in five subjects, some quantitative data on 14 C retention and radiation dosage were obtained. In comparison with animal studies, the rate of expiration of 14 CO 2 in man is slower. About 50 percent of the total radioactivity injected was lost through the respiratory route in the first hour. The total amount of expired 14 C during the 5 hr of investigation was about 75 percent of the injected dose for the five subjects. The amount of 14 C excreted as urinary 14 C-urea during the 5 hr of investigation is very small in comparison with the expired 14 C; it was only about 0.5 percent of the dose injected. The total absorbed radiation dose after complete elimination of 14 C from the body was calculated with various assumptions. The extra risk of genetic damage due to disintegration of retained 14 C in comparison with that of natural 14 C in the body during 30 living years is about 50 percent. (U.S.)

  1. Calculation of carbon-14, chlorine-37, and deuterium kinetic isotope effects in the solvolysis of tert-butyl chloride

    International Nuclear Information System (INIS)

    Burton, G.W.; Sims, L.B.; Wilson, J.C.; Fry, A.

    1977-01-01

    In the solvolysis of tert-butyl chloride, satisfactory α-carbon-14, β-deuterium, and chlorine kinetic isotope effects (KIE) may be calculated for a productlike transition state characterized by bond orders n/sub C Cl/ = 0.2, n/sub C C/ = 1.18, and n/sub C H/ = 0.94, employing a diagonal valence force field, provided that allowance is made for hydrogen-bonded solvation of the developing chloride ion with n/sub Cl H/ approx. 0.05 (approx. 7 kcal/mole hydrogen bonds). The effect of the three solvating molecules appears to be to increase the ''effective'' mass of the incipient chloride ion and to decrease the loss of zero-point energy in going to the transition state. Reaction coordinates more complicated than a simple heterolysis of the carbon-chlorine bond appear to be unnecessary and there is no advantage in employing force fields more complex than a simple valence force field containing only diagonal elements for both the reactant and the transition state model. The structural and bonding features of the proposed transition state are in accord with earlier more qualitative conclusions concerning the polar nature and productlike character of the transition state, and provide a reasonable explanation of the kinetic and equilibrium isotope effects (EIE) for the reaction. An alternative transition state model involving weak solvent nucleophilic assistance provides reasonable calculated values for the KIE, but the EIE strongly suggest the importance of solvation of the leaving group which, together with the hyperconjugation of the β hydrogens, provides a preferred explanation of the tert-butyl solvolysis results

  2. Nuclear graphite waste's behaviour under disposal conditions: Study of the release and repartition of organic and inorganic forms of carbon 14 and tritium in alkaline media

    International Nuclear Information System (INIS)

    Vende, L.

    2012-01-01

    23000 tons of graphite wastes will be generated during dismantling of the first generation of French reactors (9 gas cooled reactors). These wastes are classified as Long Lived Low Level wastes (LLW-LL). As requested by the law, the French National Radioactive Waste Management Agency (Andra) is studying concepts of low-depth disposals.In this work we focus on carbon 14, the main long-lived radionuclide in graphite waste (5730 y), but also on tritium, which is the main contributor to the radioactivity in the short term. Carbon 14 and tritium may be released from graphite waste in many forms in gaseous phase ( 14 CO 2 , HT...) or in solution ( 14 CO 3 2- , HTO...). Their speciation will strongly affect their migration from the disposal site to the environment. Leaching experiments, in alkaline solution (0.1 M NaOH simulating repository conditions) have been performed on irradiated graphite, from Saint-Laurent A2 and G2 reactors, in order to quantify their release and characterize their speciation. The studies show that carbon 14 exists in both gaseous and aqueous phases. In the gaseous phase, release is weak (≤0.1%) and corresponds to oxidizable species. Carbon 14 is mainly released into liquid phase, as both inorganic and organic species. 65% of released fraction is inorganic and 35% organic carbon. Two tritiated species have been identified in gaseous phase: HTO and HT/Organically Bond Tritium. More than 90% of tritium in that phase corresponds to HT/OBT. But release is weak (≤0.1%). HTO is mainly in the liquid phase. (author)

  3. Energy and environmental implications of carbon emission reduction targets: Case of Kathmandu Valley, Nepal

    International Nuclear Information System (INIS)

    Shrestha, Ram M.; Rajbhandari, Salony

    2010-01-01

    This paper analyzes the sectoral energy consumption pattern and emissions of CO 2 and local air pollutants in the Kathmandu Valley, Nepal. It also discusses the evolution of energy service demands, structure of energy supply system and emissions from various sectors under the base case scenario during 2005-2050. A long term energy system planning model of the Kathmandu Valley based on the MARKet ALlocation (MARKAL) framework is used for the analyses. Furthermore, the paper analyzes the least cost options to achieve CO 2 emission reduction targets of 10%, 20% and 30% below the cumulative emission level in the base case and also discusses their implications for total cost, technology-mix, energy-mix and local pollutant emissions. The paper shows that a major switch in energy use pattern from oil and gas to electricity would be needed in the Valley to achieve the cumulative CO 2 emission reduction target of 30% (ER30). Further, the share of electricity in the cumulative energy consumption of the transport sector would increase from 12% in the base case to 24% in the ER30 case.

  4. Investigations of charge-changing processes for light proton-rich nuclei on carbon and solid-hydrogen targets

    Energy Technology Data Exchange (ETDEWEB)

    Sawahata, K. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Ozawa, A., E-mail: ozawa@tac.tsukuba.ac.jp [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Saito, Y.; Abe, Y.; Ichikawa, Y.; Inaba, N.; Ishibashi, Y. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Kitagawa, A. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Matsunaga, S. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Moriguchi, T.; Nagae, D.; Okada, S. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Sato, S. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Suzuki, S. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Suzuki, T.; Takeuchi, Y.; Yamaguchi, T. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Zenihiro, J. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)

    2017-05-15

    We investigated charge-changing processes (total charge-changing cross sections and partial charge-changing cross sections) for light proton-rich nuclei ({sup 34–36}Ar, {sup 33}Cl, {sup 25–28}Si) at around 300A MeV on carbon and solid-hydrogen targets. We estimated the nuclear proton point radii of {sup 33}Cl and {sup 25,26,27}Si from the observed total charge-changing cross sections by using Glauber-model calculations with a phenomenological correction factor. Furthermore, we estimated the proton skin thickness for {sup 33}Cl coupled with its previously observed matter radius. From investigations of the partial charge-changing cross sections, clear zigzag pattern was observed for all isotopes. The present studies suggest that the pattern may be common in the proton-rich side, and depends on the odd–even nature of the fragment charge.

  5. Incremental diagnostic value of targeted biopsy using mpMRI-TRUS fusion versus 14-fragments prostatic biopsy. A prospective controlled study

    International Nuclear Information System (INIS)

    Mariotti, Guilherme C.; Falsarella, Priscila M.; Garcia, Rodrigo G.; Queiroz, Marcos R.G.; Lemos, Gustavo C.; Baroni, Ronaldo H.

    2018-01-01

    To compare the incremental diagnostic value of targeted biopsy using real-time multiparametric magnetic resonance imaging and transrectal ultrasound (mpMRI-TRUS) fusion to conventional 14-cores biopsy. Uni-institutional, institutional review board (IRB) approved prospective blinded study comparing TRUS-guided random and targeted biopsy using mpMRI-TRUS fusion, in 100 consecutive men. We included men with clinical-laboratorial suspicious for prostate cancer and Likert score ≥ 3 mp-MRI. Patients previously diagnosed with prostate cancer were excluded. All patients were submitted to 14-cores TRUS-guided biopsy (mpMRI data operator-blinded), followed by targeted biopsy using mpMRI-TRUS fusion. There was an overall increase in cancer detection rate, from 56% with random technique to 62% combining targeted biopsy using mpMRI-TRUS fusion; incremental diagnosis was even more relevant for clinically significant lesions (Gleason ≥ 7), diagnosing 10% more clinically significant lesions with fusion biopsy technique. Diagnosis upgrade occurred in 5 patients that would have negative results in random biopsies and had clinically significant tumours with the combined technique, and in 5 patients who had the diagnosis of significant tumours after fusion biopsy and clinically insignificant tumours in random biopsies(p=0.0010). Targeted biopsy using mpMRI-TRUS fusion has incremental diagnostic value in comparison to conventional random biopsy, better detecting clinically significant prostate cancers. (orig.)

  6. Incremental diagnostic value of targeted biopsy using mpMRI-TRUS fusion versus 14-fragments prostatic biopsy. A prospective controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Mariotti, Guilherme C.; Falsarella, Priscila M.; Garcia, Rodrigo G.; Queiroz, Marcos R.G. [Hospital Israelita Albert Einstein, Department of Interventional Radiology, Sao Paulo (Brazil); Lemos, Gustavo C. [Hospital Israelita Albert Einstein, Department of Urology, Sao Paulo (Brazil); Baroni, Ronaldo H. [Hospital Israelita Albert Einstein, Department of Radiology, Sao Paulo (Brazil)

    2018-01-15

    To compare the incremental diagnostic value of targeted biopsy using real-time multiparametric magnetic resonance imaging and transrectal ultrasound (mpMRI-TRUS) fusion to conventional 14-cores biopsy. Uni-institutional, institutional review board (IRB) approved prospective blinded study comparing TRUS-guided random and targeted biopsy using mpMRI-TRUS fusion, in 100 consecutive men. We included men with clinical-laboratorial suspicious for prostate cancer and Likert score ≥ 3 mp-MRI. Patients previously diagnosed with prostate cancer were excluded. All patients were submitted to 14-cores TRUS-guided biopsy (mpMRI data operator-blinded), followed by targeted biopsy using mpMRI-TRUS fusion. There was an overall increase in cancer detection rate, from 56% with random technique to 62% combining targeted biopsy using mpMRI-TRUS fusion; incremental diagnosis was even more relevant for clinically significant lesions (Gleason ≥ 7), diagnosing 10% more clinically significant lesions with fusion biopsy technique. Diagnosis upgrade occurred in 5 patients that would have negative results in random biopsies and had clinically significant tumours with the combined technique, and in 5 patients who had the diagnosis of significant tumours after fusion biopsy and clinically insignificant tumours in random biopsies(p=0.0010). Targeted biopsy using mpMRI-TRUS fusion has incremental diagnostic value in comparison to conventional random biopsy, better detecting clinically significant prostate cancers. (orig.)

  7. Ventilation of the deep Greenland and Norwegian seas: evidence from krypton-85, tritium, carbon-14 and argon-39

    International Nuclear Information System (INIS)

    Smethie, W.M. Jr.; Ostlund, H.G.; Loosli, H.H.

    1986-01-01

    On leg 5 of the TTO expedition, the distributions of 85 Kr, tritium, 14 C, 39 Ar, temperature, salinity, oxygen, carbon dioxide and nutrients were measured in the Greenland and Norwegian seas. These observations support previous observations that Greenland Sea Deep Water is formed by a deep convective process within the Greenland gyre. They also support AAGAARD et al.'s (1985, Journal of Geophysical Research, 90, 4833-4846) new hypothesis that Norwegian Sea Deep Water forms from a mixture of Greenland Sea Deep Water and Eurasian Basin Deep Water. Volume transports estimated from the distributions of 85 Kr, tritium, 14 C and 39 Ar range from 0.53 to 0.74 Sv for exchange between the surface and deep Greenland Sea and from 0.9 to 1.47 Sv for exchange between the deep Greenland and deep Norwegian Seas. The residence time of water and the deep Greenland Sea with respect to exchange with surface water ranges from 24 to 34 years reported by PETERSON and ROOTH (1976, Deep-Sea Research, 23, 273-283) and 35-42 years reported by BULLISTER and WEISS (1983, Science, 221, 265-268). The residence time of water in the deep Norwegian Sea with respect to exchange with the deep Greenland Sea ranges from 19 to 30 years compared to 97-107 years reported by PETERSON and ROOTH (1976) and 10-28 years reported by BULLISTER and WEISS (1983). The oxygen consumption rate was estimated to be at most 1.04 μM kg -1 y -1 for the deep Greenland Sea and to be between 0.47 and 0.79 μM kg -1 y -1 for the deep Norwegian Sea. (author)

  8. Laser-induced carbon plasma emission spectroscopic measurements on solid targets and in gas-phase optical breakdown

    International Nuclear Information System (INIS)

    Nemes, Laszlo; Keszler, Anna M.; Hornkohl, James O.; Parigger, Christian

    2005-01-01

    We report measurements of time- and spatially averaged spontaneous-emission spectra following laser-induced breakdown on a solid graphite/ambient gas interface and on solid graphite in vacuum, and also emission spectra from gas-phase optical breakdown in allene C3H4 and helium, and in CO2 and helium mixtures. These emission spectra were dominated by CII (singly ionized carbon), CIII (doubly ionized carbon), hydrogen Balmer beta (H b eta), and Swan C2 band features. Using the local thermodynamic equilibrium and thin plasma assumptions, we derived electron number density and electron temperature estimates. The former was in the 1016 cm -3 range, while the latter was found to be near 20000 K. In addition, the vibration-rotation temperature of the Swan bands of the C2 radical was determined to be between 4500 and 7000 K, using an exact theoretical model for simulating diatomic emission spectra. This temperature range is probably caused by the spatial inhomogeneity of the laser-induced plasma plume. Differences are pointed out in the role of ambient CO2 in a solid graphite target and in gas-phase breakdown plasma

  9. Preparation of a lipopolysaccharide from ''Escherichia coli 0111a, 0111b, K58: H21'' bacterial wall, labeled with carbon-14

    International Nuclear Information System (INIS)

    Garcia Pineda, D.; Solano, M.A.

    1980-01-01

    A brief description is made of the morphological and chemical structure of lipopolysaccharides, as well as its occurence in nature and its mechanisms of action. It is emphasized the usefulness of the labelled lipopolysaccharide for actual biochemical and biomedical research. The method for the labelling, isolation and purification of carbon-14 lipopolysaccharide is described. (auth.)

  10. Targeting Antibodies to Carbon Nanotube Field Effect Transistors by Pyrene Hydrazide Modification of Heavy Chain Carbohydrates

    Directory of Open Access Journals (Sweden)

    Steingrimur Stefansson

    2012-01-01

    Full Text Available Many carbon nanotube field-effect transistor (CNT-FET studies have used immobilized antibodies as the ligand binding moiety. However, antibodies are not optimal for CNT-FET detection due to their large size and charge. Their size can prevent ligands from reaching within the Debye length of the CNTs and a layer of charged antibodies on the circuits can drown out any ligand signal. In an attempt to minimize the antibody footprint on CNT-FETs, we examined whether pyrene hydrazide modification of antibody carbohydrates could reduce the concentration required to functionalize CNT circuits. The carbohydrates are almost exclusively on the antibody Fc region and this site-specific modification could mediate uniform antibody orientation on the CNTs. We compared the hydrazide modification of anti-E. coli O157:H7 polyclonal antibodies to pyrenebutanoic acid succinimidyl ester-coated CNTs and carbodiimide-mediated antibody CNT attachment. Our results show that the pyrene hydrazide modification was superior to those methods with respect to bacteria detection and less than 1 nM labeled antibody was required to functionalize the circuits.

  11. Storm-Related Carbon Monoxide Poisoning: An Investigation of Target Audience Knowledge and Risk Behaviors.

    Science.gov (United States)

    Damon, Scott A; Poehlman, Jon A; Rupert, Douglas J; Williams, Peyton N

    Carbon monoxide (CO) poisonings in the United States consistently occur when residents improperly use portable gasoline-powered generators and other tools following severe storms and power outages. However, protective behaviors-such as installing CO alarms and placing generators more than 20 feet away from indoor structures-can prevent these poisonings. This study identified knowledge, attitudes, and beliefs that lead consumers to adopt risk and protective behaviors for storm-related CO poisoning and post-storm generator use. Four focus groups (32 participants in total) were conducted with generator owners in winter and summer storm-prone areas to explore home safety, portable generator use, CO poisoning knowledge, and generator safety messages. Discussions were transcribed, and findings analyzed using an ordered meta-matrix approach. Although most generator owners were aware of CO poisoning, many were unsure what constitutes a safe location for generator operation and incorrectly stated that enclosed areas outside the home-such as attached garages, sheds, and covered porches-were safe. Convenience and access to appliances often dictated generator placement. Participants were receptive to installing CO alarms in their homes but were unsure where to place them. These findings suggest a deficit in understanding how to operate portable generators safely and a need to correct misconceptions around safe placement. In terms of behavioral price, the simple installation and maintenance of inexpensive CO alarms may be the most important strategy for ultimately protecting homes from both storm-related and other CO exposures.

  12. Thermo-sensitively and magnetically ordered mesoporous carbon nanospheres for targeted controlled drug release and hyperthermia application.

    Science.gov (United States)

    Chen, Lin; Zhang, Huan; Zheng, Jing; Yu, Shiping; Du, Jinglei; Yang, Yongzhen; Liu, Xuguang

    2018-03-01

    A multifunctional nanoplatform based on thermo-sensitively and magnetically ordered mesoporous carbon nanospheres (TMOMCNs) is developed for effective targeted controlled release of doxorubicin hydrochloride (DOX) and hyperthermia in this work. The morphology, specific surface area, porosity, thermo-stability, thermo-sensitivity, as well as magnetism properties of TMOMCNs were verified by high resolution transmission electron microscopy, field emission scanning electron microscopy, thermo-gravimetric analysis, X-ray diffraction, Brunauer-Emmeltt-Teller surface area analysis, dynamic light scattering and vibrating sample magnetometry measurement. The results indicate that TMOMCNs have an average diameter of ~146nm with a lower critical solution temperature at around 39.5°C. They are superparamagnetic with a magnetization of 10.15emu/g at 20kOe. They generate heat when inductive magnetic field is applied to them and have a normalized specific absorption rate of 30.23W/g at 230kHz and 290Oe, showing good potential for hyperthermia. The DOX loading and release results illustrate that the loading capacity is 135.10mg/g and release performance could be regulated by changing pH and temperature. The good targeting, DOX loading and release and hyperthermia properties of TMOMCNs offer new probabilities for high effectiveness and low toxicity of cancer chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Near-IR laser-triggered target cell collection using a carbon nanotube-based cell-cultured substrate.

    Science.gov (United States)

    Sada, Takao; Fujigaya, Tsuyohiko; Niidome, Yasuro; Nakazawa, Kohji; Nakashima, Naotoshi

    2011-06-28

    Unique near-IR optical properties of single-walled carbon nanotube (SWNTs) are of interest in many biological applications. Here we describe the selective cell detachment and collection from an SWNT-coated cell-culture dish triggered by near-IR pulse laser irradiation. First, HeLa cells were cultured on an SWNT-coated dish prepared by a spraying of an aqueous SWNT dispersion on a glass dish. The SWNT-coated dish was found to show a good cell adhesion behavior as well as a cellular proliferation rate similar to a conventional glass dish. We discovered, by near-IR pulse laser irradiation (at the laser power over 25 mW) to the cell under optical microscopic observation, a quick single-cell detachment from the SWNT-coated surface. Shockwave generation from the irradiated SWNTs is expected to play an important role for the cell detachment. Moreover, we have succeeded in catapulting the target single cell from the cultured medium when the depth of the medium was below 150 μm and the laser power was stronger than 40 mW. The captured cell maintained its original shape. The retention of the genetic information of the cell was confirmed by the polymerase chain reaction (PCR) technique. A target single-cell collection from a culture medium under optical microscopic observation is significant in wide fields of single-cell studies in biological areas.

  14. Radioactive carbon-14 dating of ground waters in IPEN for evaluation of water resources in Rio Grande do Norte and Parana basin

    International Nuclear Information System (INIS)

    Chandra, U.; Pereira, M.C.

    1986-01-01

    14 C dating of deep ground waters from Potiguar basin and Parana basin was carried out to identify zones of recharge. In all 28 samples, five from Potiguar basin and 23 from Parana basin were analyzed for 14 C. The methods of sample collection and analysis are described. The analysis consists of transforming carbon of the sample to benzene, by synthesis process involving four steps i.e. production of carbon dioxide, production of lithium carbide, hydrolysis to acetylene and catalytic polymerization to bezene. The specific activity of the synthertized benzene is measured by liquid scintillation counting. The corrections for initial 14 C content have been made by using the model of Vogel. (Author) [pt

  15. Test of the suitability of ECOPATH/ECOSIM modelling software as a compliment to estimate flows of carbon, C-14 and radionuclides in the Oeregrundsgrepen area

    Energy Technology Data Exchange (ETDEWEB)

    Sandberg, Johannes [Stockholm Univ. (Sweden). Dept. of Systems Ecology

    2004-04-01

    In this study it was evaluated whether the ECOPATH with ECOSIM software could be used as a standard platform to facilitate for radioecologists to construct and study transport and accumulation of radionuclides in aquatic food webs. The evaluation was based upon: 1) a previously published food web model of carbon/carbon-14 flow for the Oeregrundsgrepen area, Baltic Sea, 2) a generic model, 3) an ECOSIM model and 4) an ECOTRACE model. The results presented clearly shows that there is great potential for a successful development of this scientific approach in the future. The original carbon flows and assumptions was easily incorporated into the ECOPATH with ECOSIM modelling environment. The carbon flows differed only negligible between the two models, except for the benthic flows, which was more accurately described in this study. Further, by using ECOPATH it was easily discovered that the growth efficiencies used in the original model was quite high, being 47% for most of the heterotrophs, which are high from an ecological point of view. However, that is probably due to differences in how the carbon flows have been estimated in the original versus the present study. It is likely, however that the carbon demand has been underestimated in the original model. The generic model was parameterised from data available through the software as well from the diets and assumptions used in the original carbon model. The use of these parameters resulted in carbon flows, which was between 0.7 to 11 times the flows estimated by the ECOPATH model. The difference was greatest for primary producers being 3.7 to 11 times the original flows. Thus, depending on the question one is addressing it was suggested that the use of generic parameters is best for making test models of carbon and radionuclide flows in ecosystems, where the data set for validation is limited. Finally, the ECOPATH and ECOSIM model was well suited to drive a C-14 flow model, such as ECOTRACER for each of the

  16. Test of the suitability of ECOPATH/ECOSIM modelling software as a compliment to estimate flows of carbon, C-14 and radionuclides in the Oeregrundsgrepen area

    International Nuclear Information System (INIS)

    Sandberg, Johannes

    2004-04-01

    In this study it was evaluated whether the ECOPATH with ECOSIM software could be used as a standard platform to facilitate for radioecologists to construct and study transport and accumulation of radionuclides in aquatic food webs. The evaluation was based upon: 1) a previously published food web model of carbon/carbon-14 flow for the Oeregrundsgrepen area, Baltic Sea, 2) a generic model, 3) an ECOSIM model and 4) an ECOTRACE model. The results presented clearly shows that there is great potential for a successful development of this scientific approach in the future. The original carbon flows and assumptions was easily incorporated into the ECOPATH with ECOSIM modelling environment. The carbon flows differed only negligible between the two models, except for the benthic flows, which was more accurately described in this study. Further, by using ECOPATH it was easily discovered that the growth efficiencies used in the original model was quite high, being 47% for most of the heterotrophs, which are high from an ecological point of view. However, that is probably due to differences in how the carbon flows have been estimated in the original versus the present study. It is likely, however that the carbon demand has been underestimated in the original model. The generic model was parameterised from data available through the software as well from the diets and assumptions used in the original carbon model. The use of these parameters resulted in carbon flows, which was between 0.7 to 11 times the flows estimated by the ECOPATH model. The difference was greatest for primary producers being 3.7 to 11 times the original flows. Thus, depending on the question one is addressing it was suggested that the use of generic parameters is best for making test models of carbon and radionuclide flows in ecosystems, where the data set for validation is limited. Finally, the ECOPATH and ECOSIM model was well suited to drive a C-14 flow model, such as ECOTRACER for each of the

  17. A quantitative 14-3-3 interaction screen connects the nuclear exosome targeting complex to the DNA damage response

    DEFF Research Database (Denmark)

    Blasius, Melanie; Wagner, Sebastian A; Choudhary, Chuna Ram

    2014-01-01

    RNA metabolism is altered following DNA damage, but the underlying mechanisms are not well understood. Through a 14-3-3 interaction screen for DNA damage-induced protein interactions in human cells, we identified protein complexes connected to RNA biology. These include the nuclear exosome...

  18. J-type Carbon Stars: A Dominant Source of {sup 14}N-rich Presolar SiC Grains of Type AB

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Nan; Nittler, Larry R.; Alexander, Conel M. O’D.; Wang, Jianhua [Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC 20015 (United States); Stephan, Thomas; Boehnke, Patrick; Davis, Andrew M.; Trappitsch, Reto; Pellin, Michael J., E-mail: nliu@carnegiescience.edu [Department of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637 (United States)

    2017-07-20

    We report Mo isotopic data of 27 new presolar SiC grains, including 12 {sup 14}N-rich AB ({sup 14}N/{sup 15}N > 440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS grains, which came from low-mass asymptotic giant branch (AGB) stars with large s -process isotope enhancements, with the AB2 grain data demonstrates that AB2 grains show near-solar isotopic compositions and lack s -process enhancements. The near-normal Sr, Mo, and Ba isotopic compositions of AB2 grains clearly exclude born-again AGB stars, where the intermediate neutron-capture process ( i -process) takes place, as their stellar source. On the other hand, low-mass CO novae and early R- and J-type carbon stars show {sup 13}C and {sup 14}N excesses but no s -process enhancements and are thus potential stellar sources of AB2 grains. Because both early R-type carbon stars and CO novae are rare objects, the abundant J-type carbon stars (10%–15% of all carbon stars) are thus likely to be a dominant source of AB2 grains.

  19. J-type Carbon Stars: A Dominant Source of 14 N-rich Presolar SiC Grains of Type AB

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Nan; Stephan, Thomas; Boehnke, Patrick; Nittler, Larry R.; Alexander, Conel M. O’D.; Wang, Jianhua; Davis, Andrew M.; Trappitsch, Reto; Pellin, Michael J.

    2017-07-20

    We report Mo isotopic data of 27 new presolar SiC grains, including 12 N-14-rich AB (N-14/N-15 > 440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS grains, which came from low-mass asymptotic giant branch (AGB) stars with large s-process isotope enhancements, with the AB2 grain data demonstrates that AB2 grains show near-solar isotopic compositions and lack s-process enhancements. The near-normal Sr, Mo, and Ba isotopic compositions of AB2 grains clearly exclude born-again AGB stars, where the intermediate neutron-capture process (i-process) takes place, as their stellar source. On the other hand, low-mass CO novae and early R-and J-type carbon stars show C-13 and N-14 excesses but no s-process enhancements and are thus potential stellar sources of AB2 grains. Because both early R-type carbon stars and CO novae are rare objects, the abundant J-type carbon stars (10%-15% of all carbon stars) are thus likely to be a dominant source of AB2 grains.

  20. Helium-4 characteristics of groundwaters from Central Australia: Comparative chronology with chlorine-36 and carbon-14 dating techniques

    Science.gov (United States)

    Kulongoski, Justin T.; Hilton, David R.; Cresswell, Richard G.; Hostetler, Stephen; Jacobson, Gerry

    2008-01-01

    SummaryHelium isotope and concentration characteristics were determined for a suite of groundwater samples from the Amadeus Basin in Central Australia. Two study areas include a wellfield south of Alice Springs, and the Dune Plains and Mututjulu aquifers near Uluru. Measurements of 36Cl/Cl and 14C on the same sample suite enable us to assess the relative applicability of the three groundwater chronometers over a range of anticipated groundwater residence times (ages), and to investigate possible causes of discordant 'ages' derived from the different groundwater dating techniques. Results from the analyses of 39 groundwater samples reveal helium-4 ( 4He) concentrations that range from 0.80 to 98.8 (×10 -7 cm 3 STP g -1 H 2O) in the Alice Springs samples, and from 0.47 to 65.6 (×10 -7 cm 3 STP g -1 H 2O) in the Uluru samples. 4He concentrations yield uncorrected groundwater residence times (i.e. time since recharge) of between modern to >2500 ka (near Alice Springs) and modern to 1600 ka (near Uluru) assuming an effective porosity of 20%, and uranium and thorium contents of 1.7 and 6.1 ppm, respectively. 36Cl/Cl ratios on the same samples range from 93 to 158 (×10 -15) (near Alice Springs) and from 80 to 335 (×10 -15) (near Uluru) representing groundwater residence times near Alice Springs from modern to >200 ka, and from modern to >300 ka near Uluru. Percent modern carbon (pmc) on the same samples ranged from 64.9 to 12.5 pmc near Alice Springs, and from 93.5 to 30 ka. For the Amadeus Basin groundwater samples, the 4He method (uncorrected) over-estimates groundwater residence time compared to 36Cl and 14C techniques. This implies the presence of an extraneous He component or basal flux of He ( J0). To reconcile groundwater 4He and 14C residence times, it is necessary to adopt J0 values between 0 and 30 (×10 -8) cm 3 STP He cm -2 a -1 which supplements in situ produced He within the aquifer. Adoption of J0 values over this range lowers 4He residence times

  1. 14C chronology of the oldest Scandinavian church in use. An AMS/PIXE study of lime lump carbonate in the mortar

    International Nuclear Information System (INIS)

    Lindroos, Alf; Ranta, Heikki; 14C Dating Laboratory, Department of Physics and Astronomy, University of Aarhus (Denmark))" data-affiliation=" (AMS 14C Dating Laboratory, Department of Physics and Astronomy, University of Aarhus (Denmark))" >Heinemeier, Jan; Lill, Jan-Olof

    2014-01-01

    Mortar dating was applied to newly revealed, original mortar in the church of Dalby in Scania, southern Sweden which is considered to be the oldest still standing church in Scandinavia. Small white lime lumps were sampled by chipping from the supporting pillars in the interior of the church. Special emphasis was in sampling lime lumps because the church is situated in the Scania limestone area and aggregate limestone contamination was anticipated in the bulk mortars. Earlier studies have, however, shown that lime lumps do not contain aggregate material but only possible limestone rests from incomplete calcination. The sampled material was prepared for radiocarbon AMS dating. The carbonate in the lime lumps was hydrolyzed according to the sequential leaching technique developed for the Århus 14 C laboratory in Denmark. Prior to the hydrolysis the lime lumps were examined for dead-carbon contamination using a stereo microscope and cathodoluminescence. The lime lumps displayed heterogeneous carbonate luminescence. This is, however, common and it was not considered a problem because carbonate growth in changing pH/Eh conditions often leads to changing luminescence colors. Two lumps had little dead carbon contamination and an early second millennium 14 C signature. One lump, however, seemed to be heavily contaminated with dead carbon. Since the sample passed the microscopic screening, the leftovers of the lump was subjected to PIXE analysis and compared with the other two lumps. The well-defined, early 2nd millennium 14 C age of the lime lumps of this particular church is an important contribution to the discussion on stone church chronology in Scandinavia

  2. {sup 14}C chronology of the oldest Scandinavian church in use. An AMS/PIXE study of lime lump carbonate in the mortar

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, Alf, E-mail: alf.lindroos@abo.fi [Geology and Mineralogy, Department of Natural Sciences, Åbo Akademi University (Finland); Art History, Faculty of Art, Åbo Akademi University (Finland); Ranta, Heikki [Diocese of Lund, Church of Sweden (Sweden); Heinemeier, Jan [AMS " 1" 4C Dating Laboratory, Department of Physics and Astronomy, University of Aarhus (Denmark); Lill, Jan-Olof [Accelerator Laboratory, Turku PET Centre, Åbo Akademi University (Finland)

    2014-07-15

    Mortar dating was applied to newly revealed, original mortar in the church of Dalby in Scania, southern Sweden which is considered to be the oldest still standing church in Scandinavia. Small white lime lumps were sampled by chipping from the supporting pillars in the interior of the church. Special emphasis was in sampling lime lumps because the church is situated in the Scania limestone area and aggregate limestone contamination was anticipated in the bulk mortars. Earlier studies have, however, shown that lime lumps do not contain aggregate material but only possible limestone rests from incomplete calcination. The sampled material was prepared for radiocarbon AMS dating. The carbonate in the lime lumps was hydrolyzed according to the sequential leaching technique developed for the Århus {sup 14}C laboratory in Denmark. Prior to the hydrolysis the lime lumps were examined for dead-carbon contamination using a stereo microscope and cathodoluminescence. The lime lumps displayed heterogeneous carbonate luminescence. This is, however, common and it was not considered a problem because carbonate growth in changing pH/Eh conditions often leads to changing luminescence colors. Two lumps had little dead carbon contamination and an early second millennium {sup 14}C signature. One lump, however, seemed to be heavily contaminated with dead carbon. Since the sample passed the microscopic screening, the leftovers of the lump was subjected to PIXE analysis and compared with the other two lumps. The well-defined, early 2nd millennium {sup 14}C age of the lime lumps of this particular church is an important contribution to the discussion on stone church chronology in Scandinavia.

  3. SU-E-J-142: Prompt Gamma Emission Measurements From a Passively Scattered Proton Beam On Targets Containing 16O, 12C and 14N

    Energy Technology Data Exchange (ETDEWEB)

    Jeyasugiththan, J [Department of Physics, University of Cape Town, Cape Town (South Africa); Department of Clinical Oncology, Teaching Hospital, Jeffna (Sri Lanka); Peterson, S [Department of Physics, University of Cape Town, Cape Town (South Africa)

    2015-06-15

    Purpose: To measure the prompt gamma emission from the important elements found in tissue ({sup 16}O,{sup 12}C and {sup 14}N) in a clinical passive-scatter treatment environment. Methods: The targets (composed of water, Perspex, graphite and liquid nitrogen) were irradiated with a 200 MeV passive-scatter proton beam and the discrete prompt gamma energy spectra was detected by a high resolution 2′ × 2′ LaBr. detector. In order to reduce the high level of radiation produced by the beam line elements, the detector was surrounded by 10 cm of lead to attenuate the scattered gamma-rays entering the detector with an extra 5 cm thick layer of lead added along the beam direction. A 10 cm thick collimator with a 5 cm × 10 cm rectangular opening was also used. Results: The prompt gamma peaks at 6.13 MeV and 4.44 MeV were clearly identified as a Result of the inelastic nuclear reaction between the protons and the 16O atoms found in the water target. The 6.13 MeV peak was 5% higher than the peak at 4.44 MeV for the water target. The 4.44 MeV peak was the only identified emission in the prompt gamma energy spectra from the graphite target ({sup 12}C). The expected 2.313 MeV peak form the{sup 14}N (liquid nitrogen target) was identified, but the other expected {sup 14}N peaks could not be resolved. Conclusion: Prompt gamma measurements with a passive-scatter proton beam are possible, but the presence of a high amount of background radiation from the patient final collimator presents a challenge at the treatment isocenter. The prominent prompt gamma peaks at 6.13 MeV and 4.44 MeV were identified from the water, Perspex and graphite targets. The prompt gammas from the liquid nitrogen target were difficult to see, but may not be significant in the in-vivo verification process.

  4. Oesophageal heat exchangers with a diameter of 11mm or 14.7mm are equally effective and safe for targeted temperature management.

    Directory of Open Access Journals (Sweden)

    Daniel C Schroeder

    Full Text Available Targeted temperature management (TTM is widely used in critical care settings for conditions including hepatic encephalopathy, hypoxic ischemic encephalopathy, meningitis, myocardial infarction, paediatric cardiac arrest, spinal cord injury, traumatic brain injury, ischemic stroke and sepsis. Furthermore, TTM is a key treatment for patients after out-of-hospital cardiac-arrest (OHCA. However, the optimal cooling method, which is quick, safe and cost-effective still remains controversial. Since the oesophagus is adjacent to heart and aorta, fast heat-convection to the central blood-stream could be achieved with a minimally invasive oesophageal heat exchanger (OHE. To date, the optimal diameter of an OHE is still unknown. While larger diameters may cause thermal- or pressure-related tissue damage after long-term exposure to the oesophageal wall, smaller diameter (e.g., gastric tubes, up to 11mm may not provide effective cooling rates. Thus, the objective of the study was to compare OHE-diameters of 11mm (OHE11 and 14.7mm (OHE14.7 and their effects on tissue and cooling capability.Pigs were randomized to OHE11 (N = 8 or OHE14.7 (N = 8. After cooling, pigs were maintained at 33°C for 1 hour. After 10h rewarming, oesophagi were analyzed by means of histopathology. The oesophagus of four animals from a separate study that underwent exactly the identical preparation and cooling protocol described above but received a maintenance period of 24h were used as histopathological controls.Mean cooling rates were 2.8±0.4°C°C/h (OHE11 and 3.0±0.3°C °C/h (OHE14.7; p = 0.20. Occasional mild acute inflammatory transepithelial infiltrates were found in the cranial segment of the oesophagus in all groups including controls. Deviations from target temperature were 0.1±0.4°C (OHE11 and 0±0.1°C (OHE14.7; p = 0.91. Rewarming rates were 0.19±0.07°C °C/h (OHE11 and 0.20±0.05°C °C/h (OHE14.7; p = 0.75.OHE with diameters of 11 mm and 14.7 mm achieve

  5. Processing behaviors of thin-film pentacene and benzene-1,4-diboronic acid in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Ngo, Truc T.; Keegan, James E.; George, Robert D.

    2011-01-01

    This research investigates the feasibility of using supercritical carbon dioxide (scCO 2 ) as a green solvent for processing organic thin film semiconductor, such as pentacene, and a potential molecular modifier for use in electronic device applications. Benzene-1,4-diboronic acid (BDBA) was selected as a molecular modifier in this work due to its electron deficient nature, which can potentially enhance pentacene's physical, chemical or electronic properties by changing its structure in the solid state. In this study, the solubilities of BDBA and pentacene in scCO 2 are measured as individual compounds and as co-solutes, at 313 K, using ultraviolet (UV) spectroscopy. Methanol co-solvent effects on solubility have also been characterized for each compound. The results show that BDBA is insoluble in pure scCO 2 up to 1.82 × 10 7 Pa. However, with a small amount of methanol added to the mixture, BDBA becomes soluble in solution with a solubility of 3.81 × 10 −4 mol/l at 9.00 × 10 6 -Pa-pressure. In contrast, pentacene is only soluble in scCO 2 at pressures above 1.10 × 10 7 Pa, and its solubility is decreased upon addition of methanol due to the non-polar nature of pentacene. When a pentacene thin film is treated with BDBA in scCO 2 /methanol solution, BDBA sorption is observed at pressures as low as 8.80 × 10 6 Pa. Based on these results, it is concluded that treatment of pentacene thin films in scCO 2 is a promising approach that can be optimized for BDBA and other similar molecular modifiers, to produce multi-component organic thin film devices.

  6. CD14+CD16+ monocytes are the main target of Zika virus infection in peripheral blood mononuclear cells in a paediatric study in Nicaragua.

    Science.gov (United States)

    Michlmayr, Daniela; Andrade, Paulina; Gonzalez, Karla; Balmaseda, Angel; Harris, Eva

    2017-11-01

    The recent Zika pandemic in the Americas is linked to congenital birth defects and Guillain-Barré syndrome. White blood cells (WBCs) play an important role in host immune responses early in arboviral infection. Infected WBCs can also function as 'Trojan horses' and carry viruses into immune-sheltered spaces, including the placenta, testes and brain. Therefore, defining which WBCs are permissive to Zika virus (ZIKV) is critical. Here, we analyse ZIKV infectivity of peripheral blood mononuclear cells (PBMCs) in vitro and from Nicaraguan Zika patients and show CD14 + CD16 + monocytes are the main target of infection, with ZIKV replication detected in some dendritic cells. The frequency of CD14 + monocytes was significantly decreased, while the CD14 + CD16 + monocyte population was significantly expanded during ZIKV infection compared to uninfected controls. Viral RNA was detected in PBMCs from all patients, but in serum from only a subset, suggesting PBMCs may be a reservoir for ZIKV. In Zika patients, the frequency of infected cells was lower but the percentage of infected CD14 + CD16 + monocytes was significantly higher compared to dengue cases. The gene expression profile in monocytes isolated from ZIKV- and dengue virus-infected patients was comparable, except for significant differences in interferon-γ, CXCL12, XCL1, interleukin-6 and interleukin-10 levels. Thus, our study provides a detailed picture of the innate immune profile of ZIKV infection and highlights the important role of monocytes, and CD14 + CD16 + monocytes in particular.

  7. Intercomparison of ILAS-II version 1.4 and version 2 target parameters with MIPAS-Envisat measurements

    Directory of Open Access Journals (Sweden)

    A. Griesfeller

    2008-02-01

    Full Text Available This paper assesses the mean differences between the two ILAS-II data versions (1.4 and 2 by comparing them with MIPAS measurements made between May and October 2003. For comparison with ILAS-II results, MIPAS data processed at the Institut für Meteorologie und Klimaforschung, Karlsruhe, Germany (IMK in cooperation with the Instituto de Astrofísica de Andalucía (IAA in Granada, Spain, were used. The coincidence criteria of ±300 km in space and ±12 h in time for H2O, N2O, and CH4 and the coincidence criteria of ±300 km in space and ±6 h in time for ClONO2, O3, and HNO3 were used. The ILAS-II data were separated into sunrise (= Northern Hemisphere and sunset (= Southern Hemisphere. For the sunrise data, a clear improvement from version 1.4 to version 2 was observed for H2O, CH4, ClONO2, and O3. In particular, the ILAS-II version 1.4 mixing ratios of H2O and CH4 were unrealistically small, and those of ClONO2 above altitudes of 30 km unrealistically large. For N2O and HNO3, there were no large differences between the two versions. Contrary to the Northern Hemisphere, where some exceptional profiles deviated significantly from known climatology, no such outlying profiles were found in the Southern Hemisphere for both versions. Generally, the ILAS-II version 2 data were in better agreement with the MIPAS data than the version 1.4, and are recommended for quantitative analysis in the stratosphere. For H2O data in the Southern Hemisphere, further data quality evaluation is necessary.

  8. 14C fixation by leaves and leaf cell protoplasts of the submerged aquatic angiosperm Potamogeton lucens: Carbon dioxide or bicarbonate?

    International Nuclear Information System (INIS)

    Staal, M.; Elzenga, J.T.M.; Prins, H.B.A.

    1989-01-01

    Protoplasts were isolated from leaves of the aquatic angiosperm Potamogeton lucens L. The leaves utilize bicarbonate as a carbon source for photosynthesis, and show polarity; that is acidification of the periplasmic space of the lower, and alkalinization of the space near the upper leaf side. At present there are two models under consideration for this photosynthetic bicarbonate utilization process: conversion of bicarbonate into free carbon dioxide as a result of acidification and, second, a bicarbonate-proton symport across the plasma membrane. Carbon fixation of protoplasts was studied at different pH values and compared with that in leaf strips. Using the isotopic disequilibrium technique, it was established that carbon dioxide and not bicarbonate was the form in which DIC actually crossed the plasma membrane. It is concluded that there is probably no true bicarbonate transport system at the plasma membrane of these cells and that bicarbonate utilization in this species apparently rests on the conversion of bicarbonate into carbon dioxide. Experiments with acetazolamide, an inhibitor of periplasmic carbonic anhydrase, and direct measurements of carbonic anhydrase activity in intact leaves indicate that in this species the role of this enzyme for periplasmic conversion of bicarbonate into carbon dioxide is insignificant

  9. On 14C-based methods for measuring the biogenic carbon fraction in fuels and flue gases

    NARCIS (Netherlands)

    Palstra, Sanne Waltje Lieze

    2016-01-01

    Several international regulations distinguish between carbon from biomass and carbon from fossil raw materials for different materials and CO2 emissions. Due to these regulations it can be financially beneficial for companies to claim for instance their products to originate from 100% biomass, that

  10. Immobilization of carbon-14 from reactor graphite waste by use of self-sustaining reaction in the C-Al-TiO2 system

    International Nuclear Information System (INIS)

    Karlina, O.K.; Klimov, V.L.; Ojovan, M.I.; Pavlova, G.Yu.; Dmitriev, S.A.; Yurchenko, A.Yu.

    2005-01-01

    As a result of long-term neutron irradiation, the long-lived 14 C is produced in the reactor graphite. The exothermic self-sustaining reaction 3C(graphite) + 4Al + 3TiO 2 = 3TiC + 2Al 2 O 3 was proposed for processing of such waste. In doing so, the carbon, including the 14 C, is chemically bound in the stable TiC. The reaction products in the C-Al-TiO 2 system were investigated both by thermodynamic simulation and experimentally in the course of this work

  11. Non-targeted detection of chemical contamination in carbonated soft drinks using NMR spectroscopy, variable selection and chemometrics

    Energy Technology Data Exchange (ETDEWEB)

    Charlton, Adrian J. [Department for Environment, Food and Rural Affairs, Central Science Laboratory, Sand Hutton, York YO41 1LZ (United Kingdom)], E-mail: adrian.charlton@csl.gov.uk; Robb, Paul; Donarski, James A.; Godward, John [Department for Environment, Food and Rural Affairs, Central Science Laboratory, Sand Hutton, York YO41 1LZ (United Kingdom)

    2008-06-23

    An efficient method for detecting malicious and accidental contamination of foods has been developed using a combined {sup 1}H nuclear magnetic resonance (NMR) and chemometrics approach. The method has been demonstrated using a commercially available carbonated soft drink, as being capable of identifying atypical products and to identify contaminant resonances. Soft-independent modelling of class analogy (SIMCA) was used to compare {sup 1}H NMR profiles of genuine products (obtained from the manufacturer) against retail products spiked in the laboratory with impurities. The benefits of using feature selection for extracting contaminant NMR frequencies were also assessed. Using example impurities (paraquat, p-cresol and glyphosate) NMR spectra were analysed using multivariate methods resulting in detection limits of approximately 0.075, 0.2, and 0.06 mM for p-cresol, paraquat and glyphosate, respectively. These detection limits are shown to be approximately 100-fold lower than the minimum lethal dose for paraquat. The methodology presented here is used to assess the composition of complex matrices for the presence of contaminating molecules without a priori knowledge of the nature of potential contaminants. The ability to detect if a sample does not fit into the expected profile without recourse to multiple targeted analyses is a valuable tool for incident detection and forensic applications.

  12. Non-targeted detection of chemical contamination in carbonated soft drinks using NMR spectroscopy, variable selection and chemometrics

    International Nuclear Information System (INIS)

    Charlton, Adrian J.; Robb, Paul; Donarski, James A.; Godward, John

    2008-01-01

    An efficient method for detecting malicious and accidental contamination of foods has been developed using a combined 1 H nuclear magnetic resonance (NMR) and chemometrics approach. The method has been demonstrated using a commercially available carbonated soft drink, as being capable of identifying atypical products and to identify contaminant resonances. Soft-independent modelling of class analogy (SIMCA) was used to compare 1 H NMR profiles of genuine products (obtained from the manufacturer) against retail products spiked in the laboratory with impurities. The benefits of using feature selection for extracting contaminant NMR frequencies were also assessed. Using example impurities (paraquat, p-cresol and glyphosate) NMR spectra were analysed using multivariate methods resulting in detection limits of approximately 0.075, 0.2, and 0.06 mM for p-cresol, paraquat and glyphosate, respectively. These detection limits are shown to be approximately 100-fold lower than the minimum lethal dose for paraquat. The methodology presented here is used to assess the composition of complex matrices for the presence of contaminating molecules without a priori knowledge of the nature of potential contaminants. The ability to detect if a sample does not fit into the expected profile without recourse to multiple targeted analyses is a valuable tool for incident detection and forensic applications

  13. Jean-François Gallotte, Joëlle Malberg, Carbone 14 le film, Les Mutins de Pangée

    OpenAIRE

    Curien, Julie

    2014-01-01

    Carbone 14 le film est un témoignage sur le mouvement des radios libres, à travers l'exemple de « Carbone 14 », « la radio active » devenue « la radio qui vous encule par les oreilles ». Filmé en 4 jours à la rentrée 1982, avec du matériel volé, le film ovni de Jean-François Galotte et Joëlle Malberg est sélectionné au Festival de Cannes en 1983. Il fait un tollé qui retombe comme une crêpe, aux oubliettes : on n'en parle plus avant... 2011, trente ans après la création de la radio culte et c...

  14. Target laboratory

    International Nuclear Information System (INIS)

    Ephraim, D.C.; Pednekar, A.R.

    1993-01-01

    A target laboratory to make stripper foils for the accelerator and various targets for use in the experiments is set up in the pelletron accelerator facility. The facilities available in the laboratory are: (1) D.C. glow discharge setup, (2) carbon arc set up, and (3) vacuum evaporation set up (resistance heating), electron beam source, rolling mill - all for target preparation. They are described. Centrifugal deposition technique is used for target preparation. (author). 3 figs

  15. Neutronic analysis for the fission Mo99 production by irradiation of leu targets in TRIGA 14 MW reactor

    International Nuclear Information System (INIS)

    Dulugeac, S. D.; Mladin, M.; Budriman, A. G.

    2013-01-01

    Molybdenum production can be a solution for the future in the utilization of the Romanian TRIGA, taking into account the international market supply needs. Generally, two different techniques are available for Mo 99 production for use in medical Tc 99 generation.The first one is based on neutron irradiation of molybdenum targets of natural isotopic composition or enriched in Mo 98 . In a second process, Mo 99 is obtained as a result of the neutron induced fission of U 235 according to U 235 (n,f) Mo 99 . The objectives of the paper are related to Mo 99 production as a result of fission. Neutron physics parameters are determined and presented, such as: thermal flux axial distribution for the critical reactor at 10 MW inside the irradiation location; reactivity introduced by three Uranium foil containers; neutron fluxes and fission rates in the Uranium foils; released and deposited power in the Uranium foils; Mo 99 activity in the Uranium foils. (authors)

  16. Study of fractal behaviour of target fragments produced in 28Si and 32S emulsion collisions at 14.6 and 200 AGeV

    International Nuclear Information System (INIS)

    Rasool, Mir Hashim; Ahmad, Shafiq; Ahmad, M. Ayaz

    2013-01-01

    The experimental data based on 951 and 380 events of 28 Si-emulsion and 32 S-emulsion interactions at 14.6 and 200 AGeV/c respectively have been analysed to investigate intermittent behaviour and fractal properties of emission spectra of fast and slow target associated particles. The observed increasing trend in the values of fractal moments, Fqcorr and modified Gq-moments with decreasing bin size clearly reflects the evaporation model and gives an evidence for an intermittency pattern of fluctuations. The experimental data have been compared with randomly generated uncorrelated Monte Carlo of 10,000 events to check the presence of the statistical fluctuations in the target fragmentation region

  17. Implication of extracellular zinc exclusion by recombinant human calprotectin (MRP8 and MRP14) from target cells in its apoptosis-inducing activity.

    Science.gov (United States)

    Yui, Satoru; Nakatani, Yuichi; Hunter, Michael J; Chazin, Walter J; Yamazaki, Masatoshi

    2002-06-01

    Calprotectin is a calcium-binding and zinc-binding protein complex that is abundant in the cytosol of neutrophils. This factor is composed of 8 and 14 kDa subunits, which have also been termed migration inhibitory factor-related proteins MRP8 and MRP14. We previously reported that rat calprotectin purified from inflammatory neutrophils induces apoptosis of various tumor cells or normal fibroblasts in a zinc-reversible manner. The present study was undertaken to elucidate which subunit is responsible for the apoptosis-inducing activity, and to explore the mechanism of zinc-reversible apoptosis induction. The apoptosis-inducing activity of recombinant human MRP8 (rhMRP8) and recombinant human MRP14 (rhMRP14) was examined against EL-4 lymphoma cells in vitro. To determine whether zinc deprivation by calprotectin was essential for the cytotoxicity, the activity of calprotectin was tested under conditions where physical contact between the factor and the cells was precluded by a low molecular weight cut-off dialysis membrane. The cytotoxicity of rhMRP14 against EL-4 cells was first detected at 10 microM in a standard medium, whereas rhMRP8 caused only marginal cytotoxicity at 40 microM. A mixture of both proteins showed higher specific activity (onset of cytotoxicity at 5 microM). When the cells were cultured in divalent cation-depleted medium, each dose-response curve was shifted to about a four-fold lower concentration range. Calprotectin was found to induce cell death even when the complex and the target cells were separated by dialysis membrane. A membrane-impermeable zinc chelator, diethylenetriamine pentaacetic acid (DTPA), also induced target cell apoptosis in a similar time-course as calprotectin. Moreover, the activities of calprotectin and DTPA were completely inhibited by the presence of zinc ions. These data indicate that calprotectin has higher specific activity to induce apoptosis than the Individual subunits, and that the mechanism is exclusion of zinc

  18. Bio-Carbon Accounting for Bio-Oil Co-Processing: 14C and 13C/12C

    Energy Technology Data Exchange (ETDEWEB)

    Mora, Claudia I. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Li, Zhenghua [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vance, Zachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-21

    This is a powerpoint presentation on bio-carbon accounting for bio-oil co-processing. Because of the overlapping range in the stable C isotope compositions of fossil oils and biooils from C3-type feedstocks, it is widely thought that stable isotopes are not useful to track renewable carbon during co-production. In contrast, our study demonstrates the utility of stable isotopes to: • capture a record of renewable carbon allocation between FCC products of co-processing • record changes in carbon apportionments due to changes in reactor or feed temperature Stable isotope trends as a function of percent bio-oil in the feed are more pronounced when the δ13C of the bio-oil endmember differs greatly from the VGO (i.e., it has a C4 biomass source–corn stover, switch grass, Miscanthus, sugarcane– versus a C3 biomass source– pine, wheat, rice, potato), but trends on the latter case are significant for endmember differences of just a few permil. The correlation between measured 14C and δ13C may be useful as an alternative to carbon accounting, but the relationship must first be established for different bio-oil sources.

  19. Carbon-14 tracer studies in rat-liver perfusion experiments under conditions of gluconeogenesis from lactate and pyruvate

    International Nuclear Information System (INIS)

    Muellhofer, G.; Schwab, A.; Mueller, C.; Stetten, C. von; Gruber, E.

    1977-01-01

    The intracellular events in the metabolic pathway of gluconeogenesis from lactate and pyruvate in liver tissue were assumed to be understood. Nevertheless the results of several 14 C-tracer experiments gave rise to the postulation of still unknown intracellular interactions under this condition. A contribution was made to the solution of this problem by using different 14 C labelled tracers such as [1- 14 C]lactate or pyruvate and [2- 14 C]lactate or pyruvate. [ 14 C]bicarbonate and [1- 14 C]-octanoate in perfusion experiments with livers from rats under conditions of gluconeogenesis from lactate and pyruvate. The 14 C labelling patterns of intracellular metabolities such as malate, citrate, phosphoenolpyruvate, phosphoglycerate and newly synthesized glucose were analysed under different conditions. A comparison with values calculated by using metabolic models based on the generally accepted concepts of intracellular interactions showed some fundamental discrepancies which justify the postulation. (orig./MG) [de

  20. Acceleration of 14C beams in electrostatic accelerators

    International Nuclear Information System (INIS)

    Rowton, L.J.; Tesmer, J.R.

    1981-01-01

    Operational problems in the production and acceleration of 14 C beams for nuclear structure research in Los Alamos National Laboratory's Van de Graaff accelerators are discussed. Methods for the control of contamination in ion sources, accelerators and personnel are described. Sputter source target fabrication techniques and the relative beam production efficiencies of various types of bound particulate carbon sputter source targets are presented

  1. Constraints on primary and secondary particulate carbon sources using chemical tracer and 14C methods during CalNex-Bakersfield

    Data.gov (United States)

    U.S. Environmental Protection Agency — The present study investigates primary and secondary sources of organic carbon for Bakersfield, CA, USA as part of the 2010 CalNex study. The method used here...

  2. Relocation of carbon from decomposition of {sup 14}C-labelled needle and fine root litter in peat soil

    Energy Technology Data Exchange (ETDEWEB)

    Domish, T; Laine, J; Laiho, R [Helsinki Univ. (Finland). Dept. of Forest Ecology; Finer, L [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Karsisto, M [Finnish Forest Research Inst. (Finland). Dept. of Forest Ecology

    1997-12-31

    Drainage of peatlands promotes a shift of biomass and production from the ground vegetation to the trees. Thus, the above-ground (e.g. needles) and below-ground (roots) litter production of trees increases. Fine roots in particular are an important factor in the carbon and nutrient cycle in forest ecosystems. A major part of the annual net primary production of trees may be allocated below ground, the relative proportion being smaller on fertile sites than on less fertile ones. For modelling the carbon balance of drained peatlands, it is important to know the fate of carbon from newly introduced and decomposing litter. Newly added and fertilised tree litter material may be decomposed at a rate different than litter from the ground vegetation. The objectives of this study are to study the pathways of decomposing litter carbon in peat soil and to evaluate the use of the litterbag method in a controlled environment. (9 refs.)

  3. Relocation of carbon from decomposition of {sup 14}C-labelled needle and fine root litter in peat soil

    Energy Technology Data Exchange (ETDEWEB)

    Domish, T.; Laine, J.; Laiho, R. [Helsinki Univ. (Finland). Dept. of Forest Ecology; Finer, L. [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Karsisto, M. [Finnish Forest Research Inst. (Finland). Dept. of Forest Ecology

    1996-12-31

    Drainage of peatlands promotes a shift of biomass and production from the ground vegetation to the trees. Thus, the above-ground (e.g. needles) and below-ground (roots) litter production of trees increases. Fine roots in particular are an important factor in the carbon and nutrient cycle in forest ecosystems. A major part of the annual net primary production of trees may be allocated below ground, the relative proportion being smaller on fertile sites than on less fertile ones. For modelling the carbon balance of drained peatlands, it is important to know the fate of carbon from newly introduced and decomposing litter. Newly added and fertilised tree litter material may be decomposed at a rate different than litter from the ground vegetation. The objectives of this study are to study the pathways of decomposing litter carbon in peat soil and to evaluate the use of the litterbag method in a controlled environment. (9 refs.)

  4. The air quality and health co-benefits of alternative post-2020 pathways for achieving peak carbon targets in Jiangsu, China

    Science.gov (United States)

    Liu, M.; Bi, J.; Huang, Y.; Kinney, P. L.

    2016-12-01

    Jiangsu, which has three national low-carbon pilot cities, is set to be a model province in China for achieving peak carbon targets before 2030. However, according to local planning of responding to climate change, carbon emissions are projected to keep going up before 2020 even the strictest measures are implemented. In other words, innovative measures must be in action after 2020. This work aimed at assessing the air quality and health co-benefits of alternative post-2020 measures to help remove barriers of policy implementation through tying it to local incentives for air quality improvement. To achieve the aim, we select 2010 as baseline year and develop Bussiness As Usual (BAU) and Traditional Carbon Reduction (TCR) scenarios before 2020. Under BAU, only existing climate and air pollution control policies are considered; under TCR, potential climate policies in local planning and existing air pollution control policies are considered. After 2020, integrated gasification combined cycle (IGCC) plant with carbon capture and storage (CCS) technology and large-scale substitution of renewable energy seem to be two promising pathways for achieving peak carbon targets. Therefore, two additional scenarios (TCR-IGCC and TCR-SRE) are set after 2020. Based on the projections of future energy balances and industrial productions, we estimate the pollutant emissions and simulate PM2.5 and ozone concentrations by 2017, 2020, 2030 and 2050 using CMAQ. Then using health impact assessment approach, the premature deaths are estimated and monetized. Results show that the carbon peak in Jiangsu will be achieved before 2030 only under TCR-IGCC and TCR-SRE scenarios. Under three policy scenarios, Jiangsu's carbon emission control targets would have substantial effects on primary air pollutant emissions far beyond those we estimate would be needed to meet the PM2.5 concentration targets in 2017. Compared with IGCC with CCS, large-scale substitutions of renewable energy bring

  5. Carbon-14 exchange between CO2 and CO in the system 14CO2-CO-NOsub(x)(Ar, N2, O2)-quartz vessels

    International Nuclear Information System (INIS)

    Wawer, A.; Zielinski, M.

    1981-01-01

    It has been established that the rate of 14 C exchange between CO 2 and CO is diminished in presence of NO and NO 2 . The temperature dependence of the overall rate of exchange and the partial orders in respect to separate components of the exchange mixtures have been determined. The rate dependence on quartz surface has been established and the surface mechanism considered. The inhibiting action NO and NO 2 is explained. At higher pressures the catalytic effect of NO was found and explained. (author)

  6. Adherence problem for carbon films of up to 0.5 mg/cm2 on vacuum-deposited thick ferromagnetic Gd targets

    International Nuclear Information System (INIS)

    Maier-Komor, P.; Kruecken, R.; Speidel, K.-H.; Kenn, O.

    2004-01-01

    For high precision measurements of magnetic moments and reduced transition probabilities by the combined technique of projectile Coulomb excitation in inverse kinematics and transient magnetic fields sandwich targets of carbon and gadolinium were required. First preparations revealed a lack of adhesion between the Gd film and the vacuum-deposited C layer. Either the adhesion was generally poor or good results could not be reproduced. Now on a 4 mg/cm 2 Gd target 0.5 mg/cm 2 of nat C should be deposited. The Gd was deposited on 1-1.6 mg/cm 2 Ta backings and Cu films of 3.5-7 mg/cm 2 were deposited on the reverse side of the Ta backings. The adhesive properties of evaporated carbon on ferromagnetic gadolinium were investigated. For this either substrate cooling or the deposition of a 5 μg/cm 2 Ti film as adhesion agent were applied

  7. Study of the C-14-contamination potential of C-impurities in CuO and Fe

    NARCIS (Netherlands)

    Vandeputte, K; Moens, L; Dams, R; van der Plicht, Johannes

    1998-01-01

    The carbon concentration in CuO and iron was determined by isolating C. The values were in agreement with results reported in other studies. Contaminating carbon from CuO and Fe was transformed to AMS targets and measured for C-14. C-traces in CuO were shown to be the major contribution to the C-14

  8. Isotopic and chemical composition (δ13C, Δ14C, δ15N, C:N, SUVA254nm, % HPOA) of aquatic carbon and field conditions (water temperature, pH, discharge) in the Upper Mississippi River Basin, October 2014 – February 2016

    Data.gov (United States)

    Department of the Interior — This dataset contains stable isotope (δ13C) and radioisotope (Δ14C) compositions of dissolved inorganic carbon, dissolved organic carbon, particulate organic carbon,...

  9. Krypton-81, Helium-4 and Carbon-14 based estimation of groundwater ages in the Guarani Aquifer System: implications for the He-4 geochronometer

    Science.gov (United States)

    Aggarwal, P. K.; Chang, H. K.; Gastmans, D.; Sturchio, N. C.; Araguas, L.; Matsumoto, T.; Lu, Z.; Jiang, W.; Yokochi, R.; Mueller, P.

    2012-12-01

    Characterization of aquifer systems remains a challenge, particularly for large aquifers with limited hydrogeological information. Groundwater age is an important parameter that integrates aquifer recharge and flow dynamics and provides the ability to reliably constrain groundwater models. We have used multiple isotope tracers (C-14, He-4, and Kr-81) to estimate the age of groundwater along a 400-km transect in the north-eastern part of the Guarani Aquifer System (GAS) in Brazil. Carbon-14 measurements were made with an AMS, He-4 by mass-spectrometry, and Kr-81 by atom trap trace analysis (ATTA). Groundwater samples were collected along a groundwater flow path that runs from the outcrop area in the east to the deep confined section in the west, where the aquifer is up to about 1000 m deep. Present groundwater recharge occurs in the outcrop areas, as indicated by the presence of tritium and modern 14C. Carbon-14 activities reach values below detection limit at relatively short distances (a few km) from the outcrop. Abundance of 81Kr (half-life 229 Ka), in samples free of C-14, decreases from 0.81±0.11 (expressed as (81Kr/Kr)sample/(81Kr/Kr)air) in the east to 0.18±0.03 in the western-most sample (estimated age = 566±60 ka). Measured 4He-excess is far above that expected from in-situ production rates in sandstone aquifers and overestimates the age by several orders of magnitude. We used 81Kr ages to calibrate the 4He geochronometer which indicates a basal flux of about 2.8 x10-11 cm3STP He/cm2/a. This flux is lower than most estimates of basal flux in previous studies and will allow a wider use of 4He for groundwater dating and aquifer characterization.

  10. Synthesis of carbon-14 and tritium labeled cis-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]benzamidehydrochloride, an anticonvulsant agent

    International Nuclear Information System (INIS)

    Hsi, R.S.P.; Stolle, W.T.; Ayer, D.E.

    1992-01-01

    The title compound, U-54494A, is an anticonvulsant agent with clinical potential for treating epilepsy and a broad spectrum of seizure disorders. Structurally it is related to kappa opiod agonists and shares their anticonvulsant properties, but appears to be devoid of analgesic, sedative, and diuretic side effects. It also has been shown to inhibit neuronal damage and seizures induced by excitatory amino acids. This report describes the synthesis of the racemic U-54494A labeled with carbon-14 at the carboxamide carbon and with tritium in the pyrrolidine ring at C-3 and C-4. These radioisotope labeled versions of U-54494A were prepared for conducting drug disposition studies of this compound in test animals and human subjects

  11. Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at Trenches 14 and 14D on the Bow Ridge Fault at Exile Hill, Nye County, Nevada

    International Nuclear Information System (INIS)

    Taylor, E.M.; Huckins, H.E.

    1995-01-01

    Yucca Mountain, a proposed site for a high-level nuclear-waste repository, is located in southern Nevada, 20 km east of Beatty, and adjacent to the southwest comer of the Nevada Test Site (NTS) (fig. 1). Yucca Mountain is located within the Basin and Range province of the western United States. The climate is semiarid, and the flora is transitional between that of the Mojave Desert to the south and the Great Basin Desert to the north. As part of the evaluation, hydrologic conditions, especially water levels, of Yucca Mountain and vicinity during the Quaternary, and especially the past 20,000 years, are being characterized. In 1982, the US Geological Survey, in cooperation with the US Department of Energy (under interagency agreement DE-A104-78ET44802), excavated twenty-six bulldozer and backhoe trenches in the Yucca Mountain region to evaluate the nature and frequency of Quaternary faulting (Swadley and others, 1984). The trenches were oriented perpendicular to traces of suspected Quaternary faults and across projections of known bedrock faults into Quaternary deposits. Trench 14 exposes the Bow Ridge Fault on the west side of Exile Hill. Although the original purpose of the excavation of trench 14 was to evaluate the nature and frequency of Quaternary faulting on the Bow Ridge Fault, concern arose as to whether or not the nearly vertical calcium carbonate (the term ''carbonate'' in this study refers to calcium carbonate) and opaline silica veins in the fault zone were deposited by ascending waters (ground water). These veins resemble in gross morphology veins commonly formed by hydrothermal processes

  12. Synthesis of carbon C-14 labelled 2-phenyl-4-alpha-alkylaminomethyl-quinolinemethanol: a potential anti-leishmaniasis agent

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.S.T.; Fawwaz, R.A.; Heertum, R.L.van [Columbia Univ., New York, NY (United States). Coll. of Physicians and Surgeons

    1995-07-01

    Using sodium acetate, [1-{sup 14}C] as a starting material, a total of seven steps were required to synthesize the title compound. This involved acylation of ortho-dichlorobenzene to form dichloroacetophenone, [2-{sup 14}C] (I). The 2-phenyl-4-quinoline carboxylic acid, [2-{sup 14}C] (II) was prepared by the Pfitzinger reaction from (1) and dichloroisatin. Compound 11 was converted to the acid chloride (III) by reaction with SOCl{sub 2} in benzene. Grignard condensation reaction of (III) yielded 4-quinolylmethylketone, [2-{sup 14}C] (IV) which was then converted to the bromomethylketone (V). Compound V was reacted with NaBH{sub 4} to form the ethylene oxide (VI). Alkylation of the oxide yielded the title compound (VII). The overall radiochemical yield was 10.1% and the specific activity was 3.0 mCi/mmol, with a radiochemical purity of >99.5%. (author).

  13. The applicability of C-14 measurements in the soil gas for the assessment of leakage out of underground carbon dioxide reservoirs

    Directory of Open Access Journals (Sweden)

    Chałupnik Stanisław

    2014-03-01

    Full Text Available Poland, due to the ratification of the Kioto Protocol, is obliged to diminish the emission of greenhouse gases. One of the possible solutions of this problem is CO2 sequestration (CCS - carbon capture and storage. Such an option is a priority in the European Union. On the other hand, CO2 sequestration may be potentially risky in the case of gas leakage from underground reservoirs. The most dangerous event may be a sudden release of the gas onto the surface. Therefore, it is very important to know if there is any escape of CO2 from underground gas reservoirs, created as a result of sequestration. Such information is crucial to ensure safety of the population in areas located above geological reservoirs. It is possible to assess the origin of carbon dioxide, if the measurement of radiocarbon 14C concentration in this gas is done. If CO2 contains no 14C, it means, that the origin of the gas is either geological or the gas has been produced as a result of combustion of fossil fuels, like coal. A lot of efforts are focused on the development of monitoring methods to ensure safety of CO2 sequestration in geological formations. A radiometric method has been tested for such a purpose. The main goal of the investigations was to check the application possibility of such a method. The technique is based on the liquid scintillation counting of samples. The gas sample is at first bubbled through the carbon dioxide adsorbent, afterwards the adsorbent is mixed with a dedicated cocktail and measured in a low-background liquid scintillation spectrometer Quantulus. The described method enables measurements of 14C in mine and soil gas samples.

  14. Simulations of radiocarbon in a coarse-resolution world ocean model 2. Distributions of bomb-produced Carbon 14

    International Nuclear Information System (INIS)

    Toggweiler, J.R.; Dixon, K.; Bryan, K.

    1989-01-01

    Part 1 of this study examined the ability of the Geophysical Fluid Dynamics Laboratory (GFDL) primitive equation ocean general circulation model to simulate the steady state distribution of naturally produced 14 C in the ocean prior to the nuclear bomb tests of the 1950's and early 1960's. In part 2 begin with the steady state distributions of part 1 and subject the model to the pulse of elevated atmospheric 14 C concentrations observed since the 1950's

  15. Neutron-transmuted carbon-14 in neutron-irradiated GaN: Compensation of DX-like center

    International Nuclear Information System (INIS)

    Ida, T.; Oga, T.; Kuriyama, K.; Kushida, K.; Xu, Q.; Fukutani, S.

    2013-01-01

    The transmuted-C related luminescence and net carrier concentration are studied by combining photoluminescence, liquid scintillation, and Raman scattering. GaN single crystal films grown by metalorganic-vapor-phase epitaxy are irradiated with fast and thermal neutrons at fluxes of 3.9 × 10 13 cm −2 s −1 and 8.15 × 10 13 cm −2 s −1 , respectively. Irradiation time is 48 hours. The calculated 72 Ge and 14 C concentrations are 1.24 × 10 18 cm −3 and 1.13 × 10 18 cm −3 , respectively. The transmuted 14 C is detected by the liquid scintillation method to survey β-rays emitted in the process of 14 C decays from 14 N. Tritium ( 3 H) is also emitted by a (n,t) reaction of 14 N due to the neutron irradiation above 4.5 MeV. Photoluminescence relating to C, DX-like center of Ge and yellow luminescence band are observed in 1000 °C annealed NTD-GaN. The free electron concentration estimated from Raman scattering is 4.97 × 10 17 cm −3 . This value is lower than that from the transmuted Ge concentration, suggesting the compensation due to the transmuted 14 C acceptors

  16. Carbonization

    Energy Technology Data Exchange (ETDEWEB)

    Hennebutte, H G; Goutal, E

    1921-07-04

    Materials such as coal, peat, or schist are subjected to a rising temperature in successive stages in apparatus in which the distillation products are withdrawn at each stage. For example in a three-stage process, the acid products of the first or low-temperature stage are fixed in a suitable reagent, the basic products from a second or higher-temperature stage are absorbed in an acid reagent, hydrocarbons being retained by solvents, while the third are subjected to a pyrogenation process carried out in a closed vessel. Wherein the material is subjected in stages to a rising temperature, the gasified products being withdrawn at each stage, and are prevented as far as possible from mixing with the carbonized products.

  17. Study of Target Fragmentation in the Interaction of 86 MeV/A $^{12}$Carbon with Tantalum, Bismuth and Uranium

    CERN Multimedia

    2002-01-01

    Using radiochemical techniques we will ; a)~~measure the target fragment mass and charge distributions from the interaction of 86~MeV/A |1|2C with Ta, Bi and U; ; b)~~measure the target fragment forward momentum and average kinetic energy using the thick target-thick catcher technique for the above reactions; and ; c)~~measure the target fragment angular and differential energy distributions using thin target-thin catcher techniques for the reactions with Ta and U. \\\\ \\\\ These measurements should allow us to better characterize the transition between low energy and realistic heavy ion reaction mechanisms.

  18. Decreased expression of miR‑490‑3p in colorectal cancer predicts poor prognosis and promotes cell proliferation and invasion by targeting RAB14.

    Science.gov (United States)

    Wang, Bo; Yin, Mujun; Cheng, Cheng; Jiang, Hongpeng; Jiang, Kewei; Shen, Zhanlong; Ye, Yingjiang; Wang, Shan

    2018-06-19

    Growing evidence indicates a potential role for miR‑490‑3p in tumorigenesis. However, its function in colorectal carcinoma (CRC) remains undefined. In this study, miR‑490‑3p was markedly downregulated in fifty colorectal cancer tissue samples compared with the corresponding adjacent non‑cancerous specimens, by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression levels of miR‑490‑3p were closely associated with tumor differentiation and distant metastasis. In addition, both Kaplan-Meier and multivariate analyses indicated CRC patients with elevated miR‑490‑3p amounts had prolonged overall survival. Overexpression of miR‑490‑3p markedly reduced proliferation, colony formation and invasion in CRC cells by enhancing apoptosis and promoting G2/M phase arrest. Furthermore, ectopic expression of miR‑490‑3p resulted in decreased expression of RAB14, which was directly targeted by miR‑490‑3p, as shown by the dual-luciferase reporter gene assay. Finally, in a nude mouse model, miR‑490‑3p overexpression significantly suppressed the growth of CRC cells. The above results indicated that miR‑490‑3p might constitute a prognostic indicator and a novel molecular target for miRNA-based CRC therapy.

  19. Production cross section measurement of discrete gammas-ray at 90 degree for interactions of 14. 9 MeV neutrons with carbon and niobium

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Hongyu; Yan Yiming; Tang lin; Wen Chenlin; Zhang Shenji; Hua Ming; Han Chongzhan; Ding Xiaoji; Lan Liqiao; Fan Guoying; Yan Hua; Wang Xingfu; Wang Qi; Sun Suxu; Rong Yaning; Liu Shuzhen (Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing (CN))

    1989-05-01

    The cross sections of discrete gamma-ray produced by interactions of 14.9 MeV neutrons with carbon and niobium were investigated. A pulsed {ital T}({ital d},{ital n}){sup 4} He neutron source was used in the measurement. Neutron flux incident upon the sample was determined with the associated particle method. Technique of time-of-flight was used for reducing the background. A new method to calculate neutron flux attenuation in large cylindrical sample was proposed. The split of 4.439 MeV gamma-ray line from {sup 12}C({ital n},{ital n}{prime}{gamma}){sup 12}C reactions was confirmed. 79 discrete gamma-ray lines and their production cross sections for the interactions of 14.9 MeV neutrons with niobium were obtained for the first time.

  20. Non-elastic cross-sections for neutron interactions with carbon and oxygen above 14 MeV

    International Nuclear Information System (INIS)

    Brenner, D.J.; Prael, R.E.

    1985-01-01

    In the light of the new generation of high energy (less than or equal to 80 MeV) neutron therapy facilities currently being tested, the need for neutron kerma factors in the range from 15 to 80 MeV on carbon and oxygen has become of urgent importance. Not enough experimental data currently exist or are likely to be measured soon, so a nuclear model is essential for interpolation or, less satisfactorily, extrapolation of available data. The use of a suitable model, applicable to light nuclei, is shown to be crucial. Such a model is described, and good agreement between its results and the experimental data in the energy range of interest is reported. Comparisons between the model predictions and the ENDF/B-V evaluation of the non-elastic cross section for carbon between 15 and 20 MeV indicate that a re-evaluation of ENDF is required. 35 refs., 12 figs., 6 tabs

  1. Thick-target neutron, gamma-ray, and radionuclide production for protons below 12 MeV on nickel and carbon beam-stops

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.; Wilson, W.B.

    1998-03-01

    Nuclear model calculations using the GNASH code are described for protons below 12 MeV incident on nickel and carbon isotopes, for beam stop design in the Los Alamos Accelerator Production of Tritium Low Energy Demonstration Accelerator (LEDA) project. The GNASH calculations apply Hauser-Feshbach and preequilibrium reaction theories and can make use of pre-calculated direct reaction cross sections to low-lying residual nucleus states. From calculated thin target cross sections, thick target 6.7 MeV and 12 MeV proton-induced production of neutrons, gamma rays, and radionuclides are determined. Emission spectra of the secondary neutrons and gamma rays are also determined. The model calculations are validated through comparisons with experimental thin- and thick-target measurements. The results of this work are being utilized as source terms in MCNP analyses for LEDA

  2. Determination of the substrate repertoire of ADAMTS2, 3, and 14 significantly broadens their functions and identifies extracellular matrix organization and TGF-β signaling as primary targets.

    Science.gov (United States)

    Bekhouche, Mourad; Leduc, Cedric; Dupont, Laura; Janssen, Lauriane; Delolme, Frederic; Vadon-Le Goff, Sandrine; Smargiasso, Nicolas; Baiwir, Dominique; Mazzucchelli, Gabriel; Zanella-Cleon, Isabelle; Dubail, Johanne; De Pauw, Edwin; Nusgens, Betty; Hulmes, David J S; Moali, Catherine; Colige, Alain

    2016-05-01

    A disintegrin and metalloproteinase with thrombospondin type I motif (ADAMTS)2, 3, and 14 are collectively named procollagen N-proteinases (pNPs) because of their specific ability to cleave the aminopropeptide of fibrillar procollagens. Several reports also indicate that they could be involved in other biological processes, such as blood coagulation, development, and male fertility, but the potential substrates associated with these activities remain unknown. Using the recently described N-terminal amine isotopic labeling of substrate approach, we analyzed the secretomes of human fibroblasts and identified 8, 17, and 22 candidate substrates for ADAMTS2, 3, and 14, respectively. Among these newly identified substrates, many are components of the extracellular matrix and/or proteins related to cell signaling such as latent TGF-β binding protein 1, TGF-β RIII, and dickkopf-related protein 3. Candidate substrates for the 3 ADAMTS have been biochemically validated in different contexts, and the implication of ADAMTS2 in the control of TGF-β activity has been further demonstrated in human fibroblasts. Finally, the cleavage site specificity was assessed showing a clear and unique preference for nonpolar or slightly hydrophobic amino acids. This work shows that the activities of the pNPs extend far beyond the classically reported processing of the aminopropeptide of fibrillar collagens and that they should now be considered as multilevel regulators of matrix deposition and remodeling.-Bekhouche, M., Leduc, C., Dupont, L., Janssen, L., Delolme, F., Vadon-Le Goff, S., Smargiasso, N., Baiwir, D., Mazzucchelli, G., Zanella-Cleon, I., Dubail, J., De Pauw, E., Nusgens, B., Hulmes, D. J. S., Moali, C., Colige, A. Determination of the substrate repertoire of ADAMTS2, 3, and 14 significantly broadens their functions and identifies extracellular matrix organization and TGF-β signaling as primary targets. © FASEB.

  3. Biomarker and carbon isotope constraints (δ13C, Δ14C) on sources and cycling of particulate organic matter discharged by large Siberian rivers draining permafrost areas

    International Nuclear Information System (INIS)

    Winterfeld, Maria

    2014-08-01

    Circumpolar permafrost soils store about half of the global soil organic carbon pool. These huge amounts of organic matter (OM) could accumulate due to low temperatures and water saturated soil conditions over the course of millennia. Currently most of this OM remains frozen and therefore does not take part in the active carbon cycle, making permafrost soils a globally important carbon sink. Over the last decades mean annual air temperatures in the Arctic increased stronger than the global mean and this trend is projected to continue. As a result the permafrost carbon pool is under climate pressure possibly creating a positive climate feedback due to the thaw-induced release of greenhouse gases to the atmosphere. Arctic warming will lead to increased annual permafrost thaw depths and Arctic river runoff likely resulting in enhanced mobilization and export of old, previously frozen soil-derived OM. Consequently, the great arctic rivers play an important role in global biogeochemical cycles by connecting the large permafrost carbon pool of their hinterlands with the arctic shelf seas and the Arctic Ocean. The first part of this thesis deals with particulate organic matter (POM) from the Lena Delta and adjacent Buor Khaya Bay. The Lena River in central Siberia is one of the major pathways translocating terrestrial OM from its southernmost reaches near Lake Baikal to the coastal zone of the Laptev Sea. The permafrost soils from the Lena catchment area store huge amounts of pre-aged OM, which is expected to be remobilized due to climate warming. To characterize the composition and vegetation sources of OM discharged by the Lena River, the lignin phenol and carbon isotopic composition (δ 13 C and Δ 14 C) in total suspended matter (TSM) from surface waters, surface sediments from the Buor Khaya Bay along with soils from the Lena Delta's first (Holocene) and third terraces (Pleistocene ice complex) were analyzed. The lignin compositions of these samples are

  4. Functional single-walled carbon nanotubes based on an integrin αvβ3 monoclonal antibody for highly efficient cancer cell targeting

    International Nuclear Information System (INIS)

    Ou Zhongmin; Wu Baoyan; Xing Da; Zhou Feifan; Wang Huiying; Tang Yonghong

    2009-01-01

    The application of single-walled carbon nanotubes (SWNTs) in the field of biomedicine is becoming an entirely new and exciting topic. In this study, a novel functional SWNT based on an integrin α v β 3 monoclonal antibody was developed and was used for cancer cell targeting in vitro. SWNTs were first modified by phospholipid-bearing polyethylene glycol (PL-PEG). The PL-PEG functionalized SWNTs were then conjugated with protein A. A SWNT-integrin α v β 3 monoclonal antibody system (SWNT-PEG-mAb) was thus constructed by conjugating protein A with the fluorescein labeled integrin α v β 3 monoclonal antibody. In vitro study revealed that SWNT-PEG-mAb presented a high targeting efficiency on integrin α v β 3 -positive U87MG cells with low cellular toxicity, while for integrin α v β 3 -negative MCF-7 cells, the system had a low targeting efficiency, indicating that the high targeting to U87MG cells was due to the specific integrin targeting of the monoclonal antibody. In conclusion, SWNT-PEG-mAb developed in this research is a potential candidate for cancer imaging and drug delivery in cancer targeting therapy.

  5. Influence of atmospheric 14CO2 on determination of the ratio of biogenic carbon to fossil one in exhaust gases using accelerator mass spectrometry. Experimental evaluation for industrial flue gases

    International Nuclear Information System (INIS)

    Yunoki, Shunji; Saito, Masaaki; Nagakawa, Yoshiyasu

    2012-01-01

    The influence of atmospheric 14 CO 2 was evaluated on the determination of biogenic carbon ratios in industrial flue gases using accelerated mass spectrometry(AMS). Bioethanol, n-hexane, and their mixtures were combusted with a four-stroke engine, and 14 CO 2 in exhaust gases was analyzed by AMS. The experimental biogenic carbon ratio determined by ASTM D6866 method was 1.2 times higher than the theoretical value of mixed fuel containing 3.18% biogenic carbons. In general, the influence of atmospheric 14 CO 2 taken in combustion gases is neglected. It seems that the error cannot be neglected under international trading of emission allowances, where a large amount of carbons in the fuel were evaluated. The experimental value became to be the theoretical value by subtracting the amount of atmospheric 14 C from that of the samples. As the contents of biofuel increased, the experimental biogenic carbon ratios reached the theoretical values and the influence of atmospheric 14 CO 2 decreased. We recommend that the influence of atmospheric 14 CO 2 should be corrected when fuel samples contain low amounts of 14 C. (author)

  6. 14C dating and stable carbon isotopes of soil organic matter in the Southeastern region of Sao Paulo State

    International Nuclear Information System (INIS)

    Mofatto, Milene; Pessenda, Luiz Carlos Ruiz; Bendassoli, Jose Albertino; Leite, Acacio Zuniga; Oliveira, Paulo de Oliveira; Garcia, Ricardo Jose Francischetti

    2005-01-01

    The objective of this research is to characterize the isotopic composition ( 13 C, 14 C) of soil organic matter (SOM) in the Parque Estadual da Serra do Mar-Nucleo Curucutu, Sao Paulo state, Southeastern Brazil. The isotopic composition (δ 13 C) of SOM will be used as an indicator of vegetation types from the local ecosystems and 14 C dating (humin fraction) used to determine the chronology. The results from SOM indicated vegetation changes in the last 10,000 years, where, a less dense vegetation occurred in the past, with C 3 plant predominant and/or a mixture of C 3 and C 4 . (author)

  7. Impact of Different Types of Activated Carbon on the Bioaccessibility of 14C-phenanthrene in Sterile and Non-Sterile Soils

    Directory of Open Access Journals (Sweden)

    Ayodeji Oyelami

    2014-10-01

    Full Text Available In this study, the impact of three different types of activated carbon (AC on the bioaccessibility of 14C-phenanthrene in non-sterile and sterile soils was investigated. A single dose (1% of each of the different AC (CB4, CP1 and AQ5000 was blended with soil spiked with 50 mg·kg−1 of 12C/14C-phenanthrene. The mineralisation of the 14C-phenanthrene was monitored over a 14 day incubation period by indigenous soil microflora and an enriched inoculum of Pseudomonas sp., while uptake in earthworms, Eisenia fetida, was measured after incubation for 10 days at 1, 25, 50 and 100 d. Bioaccessibility was assessed using hydroxypropyl-β-cyclodextrin (HPCD solution. Results showed that the presence of AC had a significant effect upon the extents of mineralisation, earthworm uptake and HPCD extraction, when compared to the control. Aquasorb CB4 was the least effective amongst the different AC used. The characteristics of the different AC used was also seen to have a major influence on how each AC would have an effect on its use in soil remediation in reducing bioaccessibility, mobility and risk.

  8. Establishing building environmental targets to implement a low carbon objective at the district level: methodology and case study

    OpenAIRE

    FOUQUET, Marina; JUSSELME, Thomas; VAREILLES, Jérémie

    2017-01-01

    To face climate change, greenhouse gas (GHG) emission targets are specified into national policies. In France, the objective is to divide by 4 (Factor 4) the GHG emissions by 2050 comparing to 1990. The built environment, as a main contributor, is targeted by these policies: the future 2020 French regulation will set up GHG emissions targets for the building life cycle. However, the implementation of this regulation and its labels into real-estate development is challenging because it is unco...

  9. Micro-syntheses for the use of carbon 13 or carbon 14. Micro-preparations of methyl alcohol, methyl iodide, and sodium acetate labeled in the methyl group

    International Nuclear Information System (INIS)

    Baret, C.; Pichat, L.

    1951-11-01

    Apparatus and technique are described in detail for (1) reduction of CO 2 to CH 3 OH with LiAlH 4 , (2) conversion of the methanol to CH 3 I by HI, (3) formation of the Mg Grignard reagent, and (4) addition of inactive CO 2 to form CH 3 COOH. All these operations have been carried out on 0.005 moles. Methyl-labeled Na acetate has been prepared in 67% yield based on the Ba 14 CO 3 used as starting material. (author) [fr

  10. Syntheses of {gamma}-aminobutyric-1-{sup 14}C and of {alpha}-aminoadipic-6-{sup 14}C acid from methoxy-3 chloropropyl-magnesium and marked carbon dioxide; Syntheses de l'acide {gamma}-aminobutyrique{sup 14}C-1 et de l'acide {alpha}-aminoadipique {sup 14}C-6 a partir de methoxy-3 chloropropylmagnesium et d'anhydride carbonique marque

    Energy Technology Data Exchange (ETDEWEB)

    Liem, Phung Nhu [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, Departement des radioelements, Service des molecules marquees

    1967-04-01

    Carbonation of {gamma}-methoxypropyl-magnesium chloride by CO{sub 2} gives {gamma}-methoxy-butyric carboxylic-{sup 14}C acid with a yield of about 95 per cent. When the latter is treated successively with anhydrous HBr and with diazomethane, methyl carboxylic {gamma}-bromobutyrate-{sup 14}C is formed. This in turn gives {gamma}-amino-butyric carboxylic-{sup 14}C acid with an overall yield of 66 per cent with respect to Ba{sup 14}CO{sub 3}, when it is condensed with potassium phthalimide and hydrolyzed by acid. By reacting methyl-{gamma}-bromobutyrate-{sup 14}C with the sodium derivative of ethyl cyanacetamido-acetate in ethanol, followed by an acid hydrolysis, {alpha}-aminoadipic-6-{sup 14}C acid is obtained with an overall yield of 46 per cent with respect to Ba{sup 14}CO{sub 3}. (author) [French] La carbonatation du chlorure de {gamma}-methoxypropylmagnesium par {sup 14}CO{sub 2} donne l'acide {gamma}-methoxybutyrique carboxyle {sup 14}C avec un rendement d'environ 95 pour cent. Ce dernier traite successivement par HBr anhydre et par le diazomethane conduit au {gamma}-bromobutyrate de methyle carboxyle {sup 14}C. Celui-ci condense avec le phtalimide de potassium suivi d'une hydrolyse acide fournit l'acide {gamma}-aminobutyrique carboxyle {sup 14}C avec un rendement global de 66 pour cent par rapport a Ba{sup 14}CO{sub 3}. L'action du {gamma}-bromobutyrate de methyle {sup 14}C sur le derive sode du cyanacetamidoacetate d'ethyle dans l'ethanol suivie d'hydrolyse acide donne l'acide {alpha}-aminoadipique {sup 14}C-6 avec un rendement global de 46 pour cent par rapport a Ba{sup 14}CO{sub 3}. (auteur)

  11. Tendances Carbone no. 88 'The 2030 Energy and Climate targets: a (necessary?) compromise for the next milestone on the low-carbon path to 2050'

    International Nuclear Information System (INIS)

    Desai, Zuheir; Alberola, Emilie

    2014-01-01

    Among the publications of CDC Climat Research, 'Tendances Carbone' bulletin specifically studies the developments of the European market for CO 2 allowances. This issue addresses the following points: - Back-loading: the Back-loading proposal was endorsed by the Climate Change Committee and approved by the ENVI Committee. On 6 February, the European Parliament voted in favor its faster implementation. - Free allocations: on 17 January, the EU Commission gave its approval to six member states' allocation plans to issue free 2013 carbon permits. In total, 370 MtCO 2 have been allocated i.e 42 % of 2013 free allocations. - 2030 package: the EU Commission released important proposals on the EU 2030 Climate and Energy package, an impact assessment on it, a report on energy prices and costs and a legislative proposal to reform the EU ETS

  12. RGD-conjugated silica-coated gold nanorods on the surface of carbon nanotubes for targeted photoacoustic imaging of gastric cancer

    Science.gov (United States)

    Wang, Can; Bao, Chenchen; Liang, Shujing; Fu, Hualin; Wang, Kan; Deng, Min; Liao, Qiande; Cui, Daxiang

    2014-05-01

    Herein, we reported for the first time that RGD-conjugated silica-coated gold nanorods on the surface of multiwalled carbon nanotubes were successfully used for targeted photoacoustic imaging of in vivo gastric cancer cells. A simple strategy was used to attach covalently silica-coated gold nanorods (sGNRs) onto the surface of multiwalled carbon nanotubes (MWNTs) to fabricate a hybrid nanostructure. The cross-linked reaction occurred through the combination of carboxyl groups on the MWNTs and the amino group on the surface of sGNRs modified with a silane coupling agent. RGD peptides were conjugated with the sGNR/MWNT nanostructure; resultant RGD-conjugated sGNR/MWNT probes were investigated for their influences on viability of MGC803 and GES-1 cells. The nude mice models loaded with gastric cancer cells were prepared, the RGD-conjugated sGNR/MWNT probes were injected into gastric cancer-bearing nude mice models via the tail vein, and the nude mice were observed by an optoacoustic imaging system. Results showed that RGD-conjugated sGNR/MWNT probes showed good water solubility and low cellular toxicity, could target in vivo gastric cancer cells, and obtained strong photoacoustic imaging in the nude model. RGD-conjugated sGNR/MWNT probes will own great potential in applications such as targeted photoacoustic imaging and photothermal therapy in the near future.

  13. Determination of water, hydrogen, and carbon content of Korean main farm produces for the calculation of H-3 and C-14 ingestion dose

    International Nuclear Information System (INIS)

    Chung, Yang Geun; Lee, Gab Bock; Kim, Mi Ja; Eum, Hee Moon

    2003-01-01

    Water, hydrogen, and carbon content of grains, leafy vegetable, root vegetable, and fruits in Korea were determined to be used in the calculation of HTO, OBT, C-14 offsite ingestion dose. The individual items and the weighting factors of the 4 groups were based on the results of nationwide dietary intake survey in Korea. Items produced in an island or imported were excluded for the reason that they would not be affected directly by the nuclear power plants in the nation. On the same assumption, cooked and instant foods also were excluded. Items within 95% of the cumulative percentage of intake in each category were selected as the main farm produces, and then each intake percentage was taken as the weighting factor. Water, Hydrogen, and carbon content were determined using the data in Food Composition TABLE of Korea. H and C content were calculated from protein, fat, and carbohydrate content in the TABLE, and multiplied by each weighting factor to make the group-representative value. Grains, lefty and root vegetable, and fruits of Korea had 11.0%, 93.6%, 87.9%, 86.2% of water, 5.6%, 0.4%. 0.7%, 0.9% of hydrogen, and 39.6%, 2.5%, 5.2%, 6.0% of carbon, respectively. This is different from those in the ODCM from AECL data. Over ODCM, water content of grains and vegetable were 0.92-0.98 times ODCM, and fruits 1.03 times ODCM, which would result in the change of HTO ingestion dose as much. Hydrogen content of grains and vegetables are 1.02-2.33 times ODCM, but fruits 0.9 times ODCM. Carbon content of grains, leafy vegetables, and fruits are 0.7-0.98 times ODCM, but root vegetables 1.49 times ODCM. This would result in the change of ingestion dose as much

  14. Use of 14C as tracer in studies of distribution of the carbon in the plant/soil system

    International Nuclear Information System (INIS)

    Eduardo, B.P.; Cerri, C.C.

    1989-01-01

    A short time experiment with 14 C labelling, in which two-month-old sugar cane plants photosynthetically assimilated 14 CO 2 was carried out in greenhouse conditions. Data on distribution of synthesized metabolites were obtained. Although the results are referred only to dynamic conditions, which change during the vegetative cycle, it is possible to state that during this phase an important part of the metabolites go to underground compartment of the system, with considerable lose due to root respiration and rhizo-deposition. The accuracy of the technique is a good evidence of its usefulness in studies of energy transference, both within the plant and in interspecific comparisons. Longer and/or more intense labelling, associated with a longer stabilization period of the metabolites might help in studies of humification of rhizo-depositions in soil. (author)

  15. Carbon-14-ochratoxin A distribution in the Japanese quail (Coturnix coturnix japonica) monitored by whole body autoradiography

    International Nuclear Information System (INIS)

    Fuchs, R.; Appelgren, L.E.; Hagelberg, S.; Hult, K.

    1988-01-01

    Tissue distribution of the nephrotoxic mycotoxin ochratoxin A was characterized in laying Japanese quail by whole body autoradiography and scintillation counting using 14 C-labelled toxin. Periodically for 8 days after one intravenous injection of 14 microCi/bird, corresponding to 70 ng/g body weight, birds were killed, frozen, and sagittal sections of the whole body were placed on X-ray film. In general, the ochratoxin disappeared from the avian body rapidly. Specific retention of radioactivity was seen as a ring-like distribution in yolks and growing follicles. After sectioning, organs and intestinal contents were removed from carcasses in a frozen condition, homogenized, extracted, chromatographed, and the radioactivity in fractions was measured by scintillation spectroscopy. High concentrations of ochratoxin A were found in gastric intestinal contents, probably originating from toxin excreted in the bile

  16. Characterization of diverse soybean genotypes using 14 carbon for organic acid exudation under phosphorus stress and its relationship with phosphorus acquisition efficiency

    International Nuclear Information System (INIS)

    Vengavasi, Krishnapriya; Pandey, Renu

    2017-01-01

    To characterise the physiological aspects influencing organic acid exudation under low phosphorus (P) stress, experiment was conducted to screen a diverse soybean panel (comprising 116 genotypes) for total carbon exudation employing shoot labelling with 14 CO 2 technique. Among the traits measured at seedling stage, total carbon ( 14 C) exudation, P uptake and total dry weight contributed to the maximum genotypic variability in soybean. The proportion of organic acids (including oxalate, citrate, succinate and fumarate) was the highest among root-exuded compounds induced by low P stress in soybean. Improved root length, surface area and volume coupled with higher activity of enzymes in TCA cycle contributed to enhanced organic acid exudation under low P. Efficient soybean genotypes (EC-232019 and G-2344) exhibited superior growth and P acquisition efficiency under low soil P availability attributed to its higher root exudation potential aiding in mining fixed soil P. To understand the molecular mechanism differentially regulating root exudation potential in contrasting genotypes (EC-232019 and EC-113396), root proteome analysis at low P stress was carried out. Among the total proteins visualised by 2D-gel electrophoresis, 105 genotypes (32%) were differentially expressed between sufficient and low P levels. A total of 44 (14%) proteins were down-regulated by more than two-fold while 61 (15%) proteins were up-regulated by more than two-fold at low P. The differential proteins were involved in a myriad of functions including organic acid accumulation, carbohydrate, protein and lipid metabolism under low P stress. Characterisation of 17 proteins with unknown function indicated the role of novel genes under low P stress. The identified genotypes have potential to be used as donors in crop improvement programs to develop high-yielding P-efficient cultivars which may be an asset to low-input sustainable agriculture. (author)

  17. Transcriptome analysis of temporal regulation of carbon metabolism by CcpA in Bacillus subtilis reveals additional target genes

    NARCIS (Netherlands)

    Lulko, Andrzej T.; Buist, Girbe; Kok, Jan; Kuipers, Oscar P.

    2007-01-01

    The pleiotropic regulator of carbon metabolism in Grampositive bacteria, CcpA, regulates gene expression by binding to so-called cre elements, which are located either upstream or in promoter regions, or in open-reading frames. In this study we compared the transcriptomes of Bacillus subtilis 168

  18. Quantum dot tailored to single wall carbon nanotubes: a multifunctional hybrid nanoconstruct for cellular imaging and targeted photothermal therapy.

    Science.gov (United States)

    Nair, Lakshmi V; Nagaoka, Yutaka; Maekawa, Toru; Sakthikumar, D; Jayasree, Ramapurath S

    2014-07-23

    Hybrid nanomaterial based on quantum dots and SWCNTs is used for cellular imaging and photothermal therapy. Furthermore, the ligand conjugated hybrid system (FaQd@CNT) enables selective targeting in cancer cells. The imaging capability of quantum dots and the therapeutic potential of SWCNT are available in a single system with cancer targeting property. Heat generated by the system is found to be high enough to destroy cancer cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Thermo-sensitive liposomes loaded with doxorubicin and lysine modified single-walled carbon nanotubes as tumor-targeting drug delivery system.

    Science.gov (United States)

    Zhu, Xiali; Xie, Yingxia; Zhang, Yingjie; Huang, Heqing; Huang, Shengnan; Hou, Lin; Zhang, Huijuan; Li, Zhi; Shi, Jinjin; Zhang, Zhenzhong

    2014-11-01

    This report focuses on the thermo-sensitive liposomes loaded with doxorubicin and lysine-modified single-walled carbon nanotube drug delivery system, which was designed to enhance the anti-tumor effect and reduce the side effects of doxorubicin. Doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes was prepared by reverse-phase evaporation method, the mean particle size was 232.0 ± 5.6 nm, and drug entrapment efficiency was 86.5 ± 3.7%. The drug release test showed that doxorubicin released more quickly at 42℃ than at 37℃. Compared with free doxorubicin, doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes could efficiently cross the cell membranes and afford higher anti-tumor efficacy on the human hepatic carcinoma cell line (SMMC-7721) cells in vitro. For in vivo experiments, the relative tumor volumes of the sarcomaia 180-bearing mice in thermo-sensitive liposomes group and doxorubicin group were significantly smaller than those of N.S. group. Meanwhile, the combination of near-infrared laser irradiation at 808 nm significantly enhanced the tumor growth inhibition both on SMMC-7721 cells and the sarcomaia 180-bearing mice. The quality of life such as body weight, mental state, food and water intake of sarcomaia 180 tumor-bearing mice treated with doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes were much higher than those treated with doxorubicin. In conclusion, doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes combined with near-infrared laser irradiation at 808 nm may potentially provide viable clinical strategies for targeting delivery of anti-cancer drugs. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  20. Ba(OH)2.8H2O process for the removal and immobilization of carbon-14. Final report

    International Nuclear Information System (INIS)

    Haag, G.L.; Holladay, D.W.; Pitt, W.W. Jr.; Young, G.C.

    1986-01-01

    The airborne release of 14 C from various nuclear facilities has been identified as a potential biohazard due to the long half-life of 14 C (5730 years) and the ease with which it may be assimilated into the biosphere. At ORNL, technology has been developed for the removal and immobilization of this radionuclide. Prior studies have indicated that 14 C will likely exist in the oxidized form as CO 2 and will contribute slightly to the bulk CO 2 concentration of the gas stream, which is air-like in nature (approx.300 ppM/sub v/ CO 2 ). The technology that has been developed utilizes the CO 2 -Ba(OH) 2 .8H 2 O gas-solid reaction with the mode of gas-solid contacting being a fixed bed. The product, BaCO 3 , possesses excellent thermal and chemical stability, prerequisites for the long-term disposal of nuclear wastes. For optimal process operation, studies have indicated that an operating window of adequate size does exist. When operating within the window, high CO 2 removal efficiency (effluent concentrations 99%), and an acceptable pressure drop across the bed (3 kPa/m at a superficial velocity of 13 cm/s) are possible. Three areas of experimental investigation are reported: (1) microscale studies on 150-mg samples to provide information concerning surface properties, kinetics, and equilibrium vapor pressures; (2) macroscale studies on large fixed beds (4.2 kg of reactant) to determine the effects of humidity, temperature, and gas flow rate upon bed pressure drop and CO 2 breakthrough; and (3) design, construction, and operation of a pilot unit capable of continuously processing a 34-m 3 /h (20-ft 3 /min) air-based gas stream

  1. Fluorescent carbon dot-gated multifunctional mesoporous silica nanocarriers for redox/enzyme dual-responsive targeted and controlled drug delivery and real-time bioimaging.

    Science.gov (United States)

    Wang, Ying; Cui, Yu; Zhao, Yating; He, Bing; Shi, Xiaoli; Di, Donghua; Zhang, Qiang; Wang, Siling

    2017-08-01

    A distinctive and personalized nanocarrier is described here for controlled and targeted antitumor drug delivery and real-time bioimaging by combining a redox/enzyme dual-responsive disulfide-conjugated carbon dot with mesoporous silica nanoparticles (MSN-SS-CD HA ). The carbon dot with controlling and targeting abilities was prepared through a polymerizing reaction by applying citric acid and HA as starting materials (named CD HA ). The as-prepared MSN-SS-CD HA exhibited not only superior photostability and excellent biocompatibility, but also the ability to target A549 cells with overexpression of CD44 receptors. Upon loading the antitumor drug, doxorubicin (DOX), into the mesoporous channels of MSN nanoparticles, CD HA with a diameter size of 3nm completely blocked the pore entrance of DOX-encapsulated MSN nanoparticles with a pore size of about 3nm, thus preventing the premature leakage of DOX and increasing the antitumor activity until being triggered by specific stimuli in the tumor environment. The results of the cell imaging and cytotoxicity studies demonstrated that the redox/enzyme dual-responsive DOX-encapsulated MSN-SS-CD HA nanoparticles can selectively deliver and control the release of DOX into tumor cells. Ex vivo fluorescence images showed a much stronger fluorescence of MSN-SS-CD HA -DOX in the tumor site than in normal tissues, greatly facilitating the accumulation of DOX in the target tissue. However, its counterpart, MSN-SH-DOX exhibited no or much lower tumor cytotoxicity and drug accumulation in tumor tissue. In addition, MSN-SS-CD was also used as a control to investigate the ability of MSN-SS-CD HA to target A549 cells. The results obtained indicated that MSN-SS-CD HA possessed a higher cellular uptake through the CD44 receptor-mediated endocytosis compared with MSN-SS-CD in the A549 cells. Such specific redox/enzyme dual-responsive targeted nanocarriers are a useful strategy achieving selective controlled and targeted delivery of

  2. Electrochemical Behaviour of Tinidazole at 1,4-Benzoquinone Modified Carbon Paste Electrode and Its Direct Determination in Pharmaceutical Tablets and Urine by Differential Pulse Voltammetry

    Directory of Open Access Journals (Sweden)

    Yosef Nikodimos

    2017-01-01

    Full Text Available A simple and highly sensitive electrochemical method based on a 1,4-benzoquinone modified carbon paste electrode (1,4-BQMCPE was described for the determination of tinidazole (TDZ. In Britton Robinson buffer solution, TDZ yields well-defined irreversible reduction peak at −0.344 V on a 1,4-BQMCPE. Compared with that on a bare CPE, the reduction peak of TDZ increased significantly on the modified CPE and the effects of different parameters on the voltammetric responses were also investigated. Differential pulse voltammetric method was proposed and optimized for TDZ determination and its reductive peak current response at 1,4-BQMCPE was found to show linear dependence on the concentration of TDZ in the range of 1.0 × 10−6 to 5.0 × 10−4 M with a linear regression equation, correlation coefficient, limit of detection (LOD, and limit of quantification (LOQ of IPC (μA = 0.19958 + 0.02657C (μM, 0.99486, 1.10 × 10−7 M, and 3.77 × 10−7, respectively. Excellent recovery results for spiked TDZ in pharmaceutical tablet samples ranging within 97.44–97.51% and in urine ranging within 95.37–96.91% were observed. The selectivity of the method for TDZ was further studied in the presence of selected potential interferents and confirmed the potential applicability of the developed method for the determination of TDZ.

  3. Permafrost Organic Carbon Mobilization From the Watershed to the Colville River Delta: Evidence From 14C Ramped Pyrolysis and Lignin Biomarkers

    Science.gov (United States)

    Zhang, Xiaowen; Bianchi, Thomas S.; Cui, Xingqian; Rosenheim, Brad E.; Ping, Chien-Lu; Hanna, Andrea J. M.; Kanevskiy, Mikhail; Schreiner, Kathryn M.; Allison, Mead A.

    2017-11-01

    The deposition of terrestrial-derived permafrost particulate organic carbon (POC) has been recorded in major Arctic river deltas. However, associated transport pathways of permafrost POC from the watershed to the coast have not been well constrained. Here we utilized a combination of ramped pyrolysis-oxidation radiocarbon analysis (RPO 14C) along with lignin biomarkers, to track the linkages between soils and river and delta sediments. Surface and deep soils showed distinct RPO thermographs which may be related to degradation and organo-mineral interaction. Soil material in the bed load of the river channel was mostly derived from deep old permafrost. Both surface and deep soils were transported and deposited to the coast. Hydrodynamic sorting and barrier island protection played important roles in terrestrial-derived permafrost POC deposition near the coast. On a large scale, ice processes (e.g., ice gauging and strudel scour) and ocean currents controlled the transport and distribution of permafrost POC on the Beaufort Shelf.

  4. The 14C as tracer in the carbon flow assimilated by the plants (maize, sugar cane, bean) and it liberation to the soil

    International Nuclear Information System (INIS)

    Paula Eduardo, B.J.F. de.

    1987-01-01

    The flow of carbon in three different crops, maize, beans and sugar cane was studied by use of 14 V. The plants were exposed to an atmosphere with a constant concentration of the tracer for 12 hours in a biosynthesis chamber. The detection of the isotope permitted the distribution and concentration of the photosynthetates in the various organs of the plants and the losses by liberation to the soil whether by root respiration or rhizodeposition to be followed. The technique of marking metabolites through photosynthesis and their detection in the various plant organs is well known and is employed despite the requirement for hight sophisticated apparatus. On the other hand the quantification of the plant-soil-microorganism interchanges presents great difficulties being dynamic processes, showing the necessity of more detailed studies. (author) [pt

  5. Incorporation of /sup 14/C glucose into glycogen and glucose-6-phosphate dehydrogenase activity in rat brain following carbon monoxide intoxication

    Energy Technology Data Exchange (ETDEWEB)

    Sikorska, M; Gorzkowski, B; Szumanska, G; Smialek, M [Polska Akademia Nauk, Warsaw. Centrum Medycyny Doswiadczalnej i Klinicznej; Panstwowy Zaklad Higieny, Warsaw (Poland))

    1975-01-01

    Incorporation of /sup 14/C glucose into glycogen and glucose-6-phosphate dehydrogenase activity in rat brain following carbon monoxide intoxication was studied. In brains of rats tested on the 20, 30 and 60th minute of exposure to CO and immediately after removal from the chamber the enzyme activity showed no essential deviation from the control level. In the group of rats tested 1 hour after taking them out from the chamber increase of the enzyme activity was noticed, amounting to about 33% of the control value. The brains tested 24 hours after exposure showed the largest increase of the enzyme activity by about 94%. In the next time periods, 48 and 72 hours after intoxication, the enzyme activity was decreasing. The glycogen content in brains of control animals increased 3 hours after CO intoxication by about 69%. The increase of glycogen synthesis was expressed by increase of the total radioactivity, which amounted to 160% of the control value.

  6. Electrocatalytic determination of L-ascorbic acid by modified glassy carbon with Ni(Me2(CH3CO)2[14]tetraenoN4) complex.

    Science.gov (United States)

    Khorasani-Motlagh, Mozhgan; Noroozifar, Meissam

    2003-12-01

    A novel modified glassy carbon electrode containing Ni(Me2(CH3CO)2[14]tetraenoN4) complex was used as an electrocatalytic sensor for the determination of L-ascorbic acid in pH = 6.6. The peak potential shifted to negative by 205 mV compared with that for a bare electrode in cyclic voltammograms. The calibration curve was linear up to 6.2 x 10(-3) M with a detection limit 3.1 x 10(-7) M and an RSD% better than 2.47%. This newly modified electrode was applied to commercial pharmaceutical tablets, injections and foods. The obtained results were identical to those obtained by the classical 2,6-dichlorophenolindophenol method.

  7. Reaching a 1.5°C target: socio-technical challenges for a rapid transition to low-carbon electricity systems.

    Science.gov (United States)

    Eyre, Nick; Darby, Sarah J; Grünewald, Philipp; McKenna, Eoghan; Ford, Rebecca

    2018-05-13

    A 1.5°C global average target implies that we should no longer focus on merely incremental emissions reductions from the electricity system, but rather on fundamentally re-envisaging a system that, sooner rather than later, becomes carbon free. Many low-carbon technologies are surpassing mainstream predictions for both uptake and cost reduction. Their deployment is beginning to be disruptive within established systems. 'Smart technologies' are being developed to address emerging challenges of system integration, but their rates of future deployment remain uncertain. We argue that transition towards a system that can fully displace carbon generation sources will require expanding the focus of our efforts beyond technical solutions. Recognizing that change has social and technical dimensions, and that these interact strongly, we set out a socio-technical review that covers electricity infrastructure, citizens, business models and governance. It describes some of the socio-technical challenges that need to be addressed for the successful transition of the existing electricity systems. We conclude that a socio-technical understanding of electricity system transitions offers new and better insights into the potential and challenges for rapid decarbonization.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'. © 2018 The Author(s).

  8. Comparative dual-tracer studies of carbon-14 tryptophan and iodine-131 HIPDM in animal models of pancreatic diseases

    International Nuclear Information System (INIS)

    Kubota, K.; Som, P.; Brill, A.B.; Sacker, D.F.; Meinken, G.E.; Srivastava, S.C.; Atkins, H.L.

    1989-01-01

    Our previous studies have shown that a significant amount of the diamine derivative 131 I-N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3- propanediamine (HIPDM) is taken up and retained by the normal pancreas. Therefore, we studied the uptake of [ 13 1I]HIPDM in various pathophysiological models in mice (chronic alcoholism, diabetes with beta-cell atrophy and obesity with beta-cell hypertrophy) and compared to 14 C-L-Tryptophan (TRY) distribution in order to determine the factors influencing their pancreatic uptake. In normal animals, the pancreas uptake of TRY was generally higher than HIPDM. In diabetes, the relative concentration of both compounds was higher over the controls; however, in obesity, TRY showed lower accumulation than in controls while HIPDM showed no significant difference. Chronic ethanol (20%) ingestion increased TRY uptake in the pancreas compared to controls (36.88 ± 3.21 vs. 30.03 ± 4.17% ID/g; p less than 0.01) after 5 wk study period, but it decreased by 10 wk (22.36 ± 0.95% ID/g; p less than 0.005). There were no significant changes in [ 131 I]HIPDM distribution in alcoholics as compared to the controls. Radioiodinated HIPDM has potential advantages over [ 11 C]TRY for pancreatic imaging since conventional imaging techniques can be employed. Our data, however, suggest that 11 C-L-TRY is a more sensitive indicator of various pancreatic disorders

  9. Carbon and tungsten effect on characteristics of sputtered and re-deposited beryllium target layers under deuteron bombardment

    International Nuclear Information System (INIS)

    Danelyan, L.S.; Gureev, V.M.; Elistratov, N.G.

    2004-01-01

    The behavior of the plasma facing Be-elements in the International Thermonuclear Experimental Reactor ITER will be affected by the re-deposition of other eroded plasma facing materials. The effect of carbon- and tungsten-additions on the microstructure, chemical composition and hydrogen isotope accumulation in the sputtered and re-deposited layers of beryllium TGP-56 at its interaction with 200 - 300 eV hydrogen isotope ions was studied in the MAGRAS facility equipped with a magnetron sputtering system. (author)

  10. Accuracy of a rapid 10-minute carbon-14 urea breath test for the diagnosis of Helicobacter pylori-associated peptic ulcer disease

    Energy Technology Data Exchange (ETDEWEB)

    Chiahung, Kao [Taichung Veterans General Hospital (Taiwan, Province of China). Dept. of Nuclear Medicine; Shyhjen, Wang [Taichung Veterans General Hospital (Taiwan, Province of China). Dept. of Nuclear Medicine; Chungyuan, Hsu [Taichung Veterans General Hospital (Taiwan, Province of China). Dept. of Nuclear Medicine; Wanyu, Lin [Taichung Veterans General Hospital (Taiwan, Province of China). Dept. of Nuclear Medicine; Chihkua, Huang [Taichung Veterans General Hospital (Taiwan, Province of China). Dept. of Gastroenterology; Granhum, Chen [Taichung Veterans General Hospital (Taiwan, Province of China). Dept. of Gastroenterology

    1993-08-01

    Urease in the human gastric mucosa is a marker for infection with Helicobacter pylori (HP), an organism which is associated with peptic ulcer disease. To detect gastric urease, we examined 184 patients (144 males, 40 females; mean age: 49.8[+-]15.6 years) with suspected peptic ulcer disease. Fasting patients were given orally 5 [mu]Ci of carbon-14 labelled urea. For each patient only one breath sample was collected in hyamine at 10 min. The amount of [sup 14]C collected at 10 min was expressed as follows: (DPM/mmol CO[sub 2] collected)/(DPM administered)x100xbody weight (kg). The presence of HP colonization was determined by examination of multiple endoscopic prepyloric antral biopsy specimens subjected to culture or a rapid urease test. For the purpose of this study, HP-positive patients were defined as those with characteristic bacteria as indicated by a positive result of either the culture or the rapid urease test; HP-negative patients were defined as those with negative findings on both the culture and the rapid urease test. Of the 184 cases, 99 (53.8%) were positive for HP infection, and 85 (46.2%), negative. The sensitivity and specificity of the rapid 10 min [sup 14]C-urea breath test for the diagnosis of HP-associated peptic ulcer disease were evaluated by a receiver operating characteristic (ROC) curve with a variable cut-off value from 1.5 to 4.5. When a cut-off value of 1.5 was selected, the sensitivity was 100% and the specificity, 83.5%; when a cut-off value of 4.5 was selected, the sensitivity was 54.5% and the specificity, 97.6%. (orig.)

  11. Accuracy of a rapid 10-minute carbon-14 urea breath test for the diagnosis of Helicobacter pylori-associated peptic ulcer disease

    International Nuclear Information System (INIS)

    Kao Chiahung; Wang Shyhjen; Hsu Chungyuan; Lin Wanyu; Huang Chihkua; Chen Granhum

    1993-01-01

    Urease in the human gastric mucosa is a marker for infection with Helicobacter pylori (HP), an organism which is associated with peptic ulcer disease. To detect gastric urease, we examined 184 patients (144 males, 40 females; mean age: 49.8±15.6 years) with suspected peptic ulcer disease. Fasting patients were given orally 5 μCi of carbon-14 labelled urea. For each patient only one breath sample was collected in hyamine at 10 min. The amount of 14 C collected at 10 min was expressed as follows: [(DPM/mmol CO 2 collected)/(DPM administered)]x100xbody weight (kg). The presence of HP colonization was determined by examination of multiple endoscopic prepyloric antral biopsy specimens subjected to culture or a rapid urease test. For the purpose of this study, HP-positive patients were defined as those with characteristic bacteria as indicated by a positive result of either the culture or the rapid urease test; HP-negative patients were defined as those with negative findings on both the culture and the rapid urease test. Of the 184 cases, 99 (53.8%) were positive for HP infection, and 85 (46.2%), negative. The sensitivity and specificity of the rapid 10 min 14 C-urea breath test for the diagnosis of HP-associated peptic ulcer disease were evaluated by a receiver operating characteristic (ROC) curve with a variable cut-off value from 1.5 to 4.5. When a cut-off value of 1.5 was selected, the sensitivity was 100% and the specificity, 83.5%; when a cut-off value of 4.5 was selected, the sensitivity was 54.5% and the specificity, 97.6%. (orig.)

  12. Synthesis of carbon-13 labelled carbonaceous deposits and their evaluation for potential use as surrogates to better understand the behaviour of the carbon-14-containing deposit present in irradiated PGA graphite

    Energy Technology Data Exchange (ETDEWEB)

    Payne, L., E-mail: liam.payne@bristol.ac.uk [Interface Analysis Centre, HH Wills Physics Laboratory, University of Bristol, BS8 1TL (United Kingdom); Walker, S.; Bond, G. [Centre for Materials Science, University of Central Lancashire, PR1 2HE (United Kingdom); Eccles, H. [John Tyndall Institute for Nuclear Research, School of Computing, Engineering and Physical Sciences, University of Central Lancashire, PR1 2HE (United Kingdom); Heard, P.J.; Scott, T.B. [Interface Analysis Centre, HH Wills Physics Laboratory, University of Bristol, BS8 1TL (United Kingdom); Williams, S.J. [Radioactive Waste Management, B587, Curie Avenue, Harwell Oxford, Didcot, OX11 0RH (United Kingdom)

    2016-03-15

    The present work has used microwave plasma chemical vapour deposition to generate suitable isotopically labelled carbonaceous deposits on the surface of Pile Grade A graphite for use as surrogates for studying the behaviour of the deposits observed on irradiated graphite extracted from UK Magnox reactors. These deposits have been shown elsewhere to contain an enhanced concentration of {sup 14}C compared to the bulk graphite. A combination of Raman spectroscopy, ion beam milling with scanning electron microscopy and secondary ion mass spectrometry were used to determine topography and internal morphology in the formed deposits. Direct comparison was made against deposits found on irradiated graphite samples trepanned from a Magnox reactor core and showed a good similarity in appearance. This work suggests that the microwave plasma chemical vapour deposition technique is of value in producing simulant carbon deposits, being of sufficiently representative morphology for use in non-radioactive surrogate studies of post-disposal behaviour of {sup 14}C-containing deposits on some irradiated Magnox reactor graphite.

  13. Calibration of an analyzing magnet using the 12C(d, p0)13C nuclear reaction with a thick carbon target

    Science.gov (United States)

    Andrade, E.; Canto, C. E.; Rocha, M. F.

    2017-09-01

    The absolute energy of an ion beam produced by an accelerator is usually determined by an electrostatic or magnetic analyzer, which in turn must be calibrated. Various methods for accelerator energy calibration are extensively reported in the literature, like nuclear reaction resonances, neutron threshold, and time of flight, among others. This work reports on a simple method to calibrate the magnet associated to a vertical 5.5 MV Van de Graaff accelerator. The method is based on bombarding with deuteron beams a thick carbon target and measuring with a surface barrier detector the particle energy spectra produced. The analyzer magnetic field is measured for each spectrum and the beam energy is deduced by the best fit of the simulation of the spectrum with the SIMNRA code that includes 12C(d,p0)13C nuclear cross sections.

  14. Multiplicity of secondary electrons emitted by carbon thin targets by impact of H0, H2+ and H3+ projectiles at MeV energies

    International Nuclear Information System (INIS)

    Vidovic, Zvonimir

    1997-01-01

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25 - 2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. Phenomenological and theoretical descriptions as well as a summary of the main theoretical models are the subjects of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of the thin carbon foils crossed by an energetic projectile is described in the chapter two. In this chapter there are also presented the method and the algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H 0 atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of the ions with solids. The role of the proximity of the protons, molecular ions fragments, upon the amplitude of these collected effects is evidenced from the study of the statistics of forward emission. The experiments allowed us to shed light on various aspects of atom and polyatomic ion interactions with solid surfaces. (author)

  15. Cross sections for charge change in argon and equilibrium charge states of 3.5 MeV/amu uranium ions passing through argon and carbon targets

    International Nuclear Information System (INIS)

    Perumal, A.N.; Horvat, V.; Watson, R.L.; Peng, Y.; Fruchey, K.S.

    2005-01-01

    Cross sections for single and multiple electron capture and loss were measured for 3.5 MeV/amu uranium ions, traveling in argon gas, as a function of incident charge state. Multiple electron loss in single collisions was found to contribute significantly to the total loss cross section. The measured cross sections were used to determine the average equilibrium charge in argon by three different methods. The resulting charges were in good agreement with each other and with the effective charge calculated from stopping powers. In order to investigate the gas-solid (density) effect on the average equilibrium charge, the charge distributions of 3.5 MeV/amu uranium ions emerging from carbon foils of different thicknesses were measured. It was found that the average equilibrium charge of the uranium ions emerging from the solid is 41% larger than that of the uranium ions emerging from the gas. The energy dependences of the average equilibrium charges for uranium ions exiting carbon and argon targets were examined by combining the present results with previous results of other investigators and compared with the predictions of a semiempirical formula developed recently by Schiwietz and Grande

  16. Target preparation