WorldWideScience

Sample records for target elements carbon

  1. Carbon black vs. black carbon and other airborne materials containing elemental carbon: Physical and chemical distinctions

    International Nuclear Information System (INIS)

    Long, Christopher M.; Nascarella, Marc A.; Valberg, Peter A.

    2013-01-01

    Airborne particles containing elemental carbon (EC) are currently at the forefront of scientific and regulatory scrutiny, including black carbon, carbon black, and engineered carbon-based nanomaterials, e.g., carbon nanotubes, fullerenes, and graphene. Scientists and regulators sometimes group these EC-containing particles together, for example, interchangeably using the terms carbon black and black carbon despite one being a manufactured product with well-controlled properties and the other being an undesired, incomplete-combustion byproduct with diverse properties. In this critical review, we synthesize information on the contrasting properties of EC-containing particles in order to highlight significant differences that can affect hazard potential. We demonstrate why carbon black should not be considered a model particle representative of either combustion soots or engineered carbon-based nanomaterials. Overall, scientific studies need to distinguish these highly different EC-containing particles with care and precision so as to forestall unwarranted extrapolation of properties, hazard potential, and study conclusions from one material to another. -- Highlights: •Major classes of elemental carbon-containing particles have distinct properties. •Despite similar names, carbon black should not be confused with black carbon. •Carbon black is distinguished by a high EC content and well-controlled properties. •Black carbon particles are characterized by their heterogenous properties. •Carbon black is not a model particle representative of engineered nanomaterials. -- This review demonstrates the significant physical and chemical distinctions between elemental carbon-containing particles e.g., carbon black, black carbon, and engineered nanomaterials

  2. ICP-AES determination of trace elements in carbon steel

    International Nuclear Information System (INIS)

    Sengupta, Arijit; Rajeswari, B.; Kadam, R.M.; Babu, Y.; Godbole, S.V.

    2010-01-01

    Full text: Carbon steel, a combination of the elements iron and carbon, can be classified into four types as mild, medium, high and very high depending on the carbon content which varies from 0.05% to 2.1%. Carbon steel of different types finds application in medical devices, razor blades, cutlery and spring. In the nuclear industry, it is used in feeder pipes in the reactor. A strict quality control measure is required to monitor the trace elements, which have deleterious effects on the mechanical properties of the carbon steel. Thus, it becomes imperative to check the purity of carbon steel as a quality control measure before it is used in feeder pipes in the reactor. Several methods have been reported in literature for trace elemental determination in high purity iron. Some of these include neutron activation analysis, atomic absorption spectrometry and atomic emission spectrometry. Inductively coupled plasma atomic emission spectrometry (ICP-AES) is widely recognized as a sensitive technique for the determination of trace elements in various matrices, its major advantages being good accuracy and precision, high sensitivity, multi-element capability, large linear dynamic range and relative freedom from matrix effects. The present study mainly deals with the direct determination of trace elements in carbon steel using ICP-AES. An axially viewing ICP spectrometer having a polychromator with 35 fixed analytical channels and limited sequential facility to select any analytical line within 2.2 nm of a polychromator line was used in these studies. Iron, which forms one of the main constituents of carbon steel, has a multi electronic configuration with line rich emission spectrum and, therefore, tends to interfere in the determination of trace impurities in carbon steel matrix. Spectral interference in ICP-AES can be seriously detrimental to the accuracy and reliability of trace element determinations, particularly when they are performed in the presence of high

  3. Uranium fluoride and metallic uranium as target materials for heavy-element experiments at SHIP

    Energy Technology Data Exchange (ETDEWEB)

    Kindler, Birgit [Gesellschaft fuer Schwerionenforschung (GSI), Planckstrasse 1, D-64291 Darmstadt (Germany)], E-mail: b.kindler@gsi.de; Ackermann, Dieter; Hartmann, Willi; Hessberger, Fritz Peter; Hofmann, Sigurd; Huebner, Annett; Lommel, Bettina; Mann, Rido; Steiner, Jutta [Gesellschaft fuer Schwerionenforschung (GSI), Planckstrasse 1, D-64291 Darmstadt (Germany)

    2008-06-01

    In this contribution we describe the production and application of uranium targets for synthesis of heavy elements. The targets are prepared from uranium fluoride (UF{sub 4}) and from metallic uranium with thin carbon foils as backing. Targets of UF{sub 4} were produced by thermal evaporation in a similar way as the frequently applied targets out of Bi, Bi{sub 2}O{sub 3}, Pb, PbS, SmF{sub 3}, and NdF{sub 3,} prepared mostly from isotopically enriched material [Birgit Kindler, et al., Nucl. Instr. and Meth. A 561 (2006) 107; Bettina Lommel, et al., Nucl. Instr. and Meth. A 561 (2006) 100]. In order to use more intensive beams and to avoid scattering of the reaction products in the target, metallic uranium is favorable. However, evaporation of metallic uranium is not feasible at a sustainable yield. Therefore, we established magnetron sputtering of metallic uranium. We describe production and properties of these targets. First irradiation tests show promising results.

  4. Retention of elemental 131I by activated carbons under accident conditions

    International Nuclear Information System (INIS)

    Deuber, H.

    1984-09-01

    Under simulated accident conditions (maximum temperature: 130 0 C) no significant difference was found in the retention of I-131 loaded as elemental iodine, by various fresh and aged commercial activated carbons. In all the cases, the I-131 passing through deep beds of activated carbon was in a non-elemental form. It is concluded that a minimum retention of 99.99% for elemental radioiodine, as required by the RSK guidelines for PWR accident filters, can be equally well achieved with various commercial activated carbons. (orig.) [de

  5. Scavenging of particulate elemental carbon into stratus cloud

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyasu, Naoki; Maeda, Takahisa [National Inst. for Resources and Environment, Tsukuba (Japan)

    1995-12-31

    The role of atmospheric aerosols on the alternation of cloud radiative properties has widely been recognized since 1977 when Tomey and his coworkers have numerically demonstrated the effect of increased cloud condensation nuclei (CCN). At the same time, cloud processes are one of the most important factor in controlling the residence time of atmospheric aerosols through the wet removal process. The redistribution of the size and the composition of pre-cloud aerosols is also the important role of cloud process on the nature of atmospheric aerosols. In order to study these cloud-aerosol interaction phenomena, the incorporation of aerosols into cloud droplets is the first mechanism to be investigated. Among the several mechanisms for the incorporation of aerosols into cloud droplets, nucleation scavenging, is the potentially important process in the view of cloud-aerosol interactions. This critical supersaturation for a given radius of a particle can be theoretically calculated only for pure species, e.g., NaCl. However, a significant portion of the atmospheric aerosols is in the form of internal mixture of multiple components, such as SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +} and particulate elemental carbon. The knowledge acquired by field measurements is therefore essential on this subject. The present study focuses on the scavenging of major components of urban atmospheric aerosols, in particular the incorporation of particulate elemental carbon into stratus cloud. Particulate elemental carbon is the strongest light absorbing species in visible region, and has potential to change the optical property of cloud. On the basis of the measurements conducted at a mountain located in the suburb of Tokyo Metropolitan area, Japan, some insights on the scavenging of particulate elemental carbon into cloud droplet will be presented

  6. Scavenging of particulate elemental carbon into stratus cloud

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyasu, Naoki; Maeda, Takahisa [National Inst. for Resources and Environment, Tsukuba (Japan)

    1996-12-31

    The role of atmospheric aerosols on the alternation of cloud radiative properties has widely been recognized since 1977 when Tomey and his coworkers have numerically demonstrated the effect of increased cloud condensation nuclei (CCN). At the same time, cloud processes are one of the most important factor in controlling the residence time of atmospheric aerosols through the wet removal process. The redistribution of the size and the composition of pre-cloud aerosols is also the important role of cloud process on the nature of atmospheric aerosols. In order to study these cloud-aerosol interaction phenomena, the incorporation of aerosols into cloud droplets is the first mechanism to be investigated. Among the several mechanisms for the incorporation of aerosols into cloud droplets, nucleation scavenging, is the potentially important process in the view of cloud-aerosol interactions. This critical supersaturation for a given radius of a particle can be theoretically calculated only for pure species, e.g., NaCl. However, a significant portion of the atmospheric aerosols is in the form of internal mixture of multiple components, such as SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +} and particulate elemental carbon. The knowledge acquired by field measurements is therefore essential on this subject. The present study focuses on the scavenging of major components of urban atmospheric aerosols, in particular the incorporation of particulate elemental carbon into stratus cloud. Particulate elemental carbon is the strongest light absorbing species in visible region, and has potential to change the optical property of cloud. On the basis of the measurements conducted at a mountain located in the suburb of Tokyo Metropolitan area, Japan, some insights on the scavenging of particulate elemental carbon into cloud droplet will be presented

  7. Actinide targets for the synthesis of super-heavy elements

    International Nuclear Information System (INIS)

    Roberto, J.B.; Alexander, C.W.; Boll, R.A.; Burns, J.D.; Ezold, J.G.; Felker, L.K.; Hogle, S.L.; Rykaczewski, K.P.

    2015-01-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of "4"8Ca beams on actinide targets. These target materials, including "2"4"2Pu, "2"4"4Pu, "2"4"3Am, "2"4"5Cm, "2"4"8Cm, "2"4"9Cf, and "2"4"9Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including "2"4"9Bk, "2"5"1Cf, and "2"5"4Es are described.

  8. Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

    Science.gov (United States)

    Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

    2013-10-01

    The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

  9. Whole genome resequencing reveals natural target site preferences of transposable elements in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Raquel S Linheiro

    Full Text Available Transposable elements are mobile DNA sequences that integrate into host genomes using diverse mechanisms with varying degrees of target site specificity. While the target site preferences of some engineered transposable elements are well studied, the natural target preferences of most transposable elements are poorly characterized. Using population genomic resequencing data from 166 strains of Drosophila melanogaster, we identified over 8,000 new insertion sites not present in the reference genome sequence that we used to decode the natural target preferences of 22 families of transposable element in this species. We found that terminal inverted repeat transposon and long terminal repeat retrotransposon families present clade-specific target site duplications and target site sequence motifs. Additionally, we found that the sequence motifs at transposable element target sites are always palindromes that extend beyond the target site duplication. Our results demonstrate the utility of population genomics data for high-throughput inference of transposable element targeting preferences in the wild and establish general rules for terminal inverted repeat transposon and long terminal repeat retrotransposon target site selection in eukaryotic genomes.

  10. Simply scan--optical methods for elemental carbon measurement in diesel exhaust particulate.

    Science.gov (United States)

    Forder, James A

    2014-08-01

    This article describes a performance assessment of three optical methods, a Magee Scientific OT21 Transmissometer, a Hach-Lange Microcolor II difference gloss meter, and a combination of an office scanner with Adobe Photoshop software. The optical methods measure filter staining as a proxy for elemental carbon in diesel exhaust particulate (DEP) exposure assessment and the suitability of each as a replacement for the existing Bosch meter optical method. Filters loaded with DEP were produced from air in a non-coal mine and the exhaust gases from a mobile crane. These were measured with each apparatus and then by combustion to obtain a reference elemental carbon value. The results from each apparatus were then plotted against both the Bosch number and reference elemental carbon values. The equations of the best fit lines for these plots were derived, and these gave functions for elemental carbon and Bosch number from the output of each new optical method. For each optical method, the range of DEP loadings which can be measured has been determined, and conversion equations for elemental carbon and Bosch number have been obtained. All three optical methods studied will effectively quantify blackness as a measure of elemental carbon. Of these the Magee Scientific OT21 transmissometer has the best performance. The Microcolor II and scanner/photoshop methods will in addition allow conversion to Bosch number which may be useful if historical Bosch data are available and functions for this are described. The scanner/photoshop method demonstrates a technique to obtain measurements of DEP exposure without the need to purchase specialized instrumentation. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  11. Elemental and organic carbon in aerosols over urbanized coastal region (southern Baltic Sea, Gdynia).

    Science.gov (United States)

    Lewandowska, Anita; Falkowska, Lucyna; Murawiec, Dominika; Pryputniewicz, Dorota; Burska, Dorota; Bełdowska, Magdalena

    2010-09-15

    Studies on PM 10, total particulate matter (TSP), elemental carbon (EC) and organic carbon (OC) concentrations were carried out in the Polish coastal zone of the Baltic Sea, in urbanized Gdynia. The interaction between the land, the air and the sea was clearly observed. The highest concentrations of PM 10, TSP and both carbon fractions were noted in the air masses moving from southern and western Poland and Europe. The EC was generally of primary origin and its contribution to TSP and PM 10 mass was on average 2.3% and 3.7% respectively. Under low wind speed conditions local sources (traffic and industry) influenced increases in elemental carbon and PM 10 concentrations in Gdynia. Elemental carbon demonstrated a pronounced weekly cycle, yielding minimum values at the weekend and maximum values on Thursdays. The role of harbors and ship yards in creating high EC concentrations was clearly observed. Concentration of organic carbon was ten times higher than that of elemental carbon, and the average OC contribution to PM 10 mass was very high (31.6%). An inverse situation was observed when air masses were transported from over the Atlantic Ocean, the North Sea and the Baltic Sea. These clean air masses were characterized by the lowest concentrations of all analysed compounds. Obtained results for organic and elemental carbon fluxes showed that atmospheric aerosols can be treated, along with water run-off, as a carbon source for the coastal waters of the Baltic Sea. The enrichment of surface water was more effective in the case of organic carbon (0.27+/-0.19 mmol m(-2) d(-1)). Elemental carbon fluxes were one order of magnitude smaller, on average 0.03+/-0.04 mmol m(-2) d(-1). We suggest that in some situations atmospheric carbon input can explain up to 18% of total carbon fluxes into the Baltic coastal waters. Copyright 2010 Elsevier B.V. All rights reserved.

  12. 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.

  13. Development of electrically heated rods with resistive element of graphite or carbon/carbon composites for simulating transients in nuclear reactors

    International Nuclear Information System (INIS)

    Polidoro, H.A.

    1987-01-01

    Thermo-hydraulic problems, in nuclear plants are normally analysed by the use of electrically heated rods. The direct or indirect heater rods are limited in their use because, for high temperatures and high heat flux, the heating element temperature approach its melting point. The use of platinum or tantalum is not economically viable. Graphite and carbon/carbon composites are alternative materials because they are good electrical conductors and have good mechanical properties at high temperatures. Graphite and carbon/carbon composites were used to make heating elements for testing by indirect heating. The swaging process used to reduce the cladding diameter prevented the fabrication of graphite heater rods. Carbon/carbon composite used to make heating elements gave good results up to a heat flux of 100 W/cm 2 . It is easy to verify that this value can be exceeded if the choice of the complementary materials for insulator and cladding improved. (author) [pt

  14. 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.

  15. 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.

  16. Development of a thermal method for the measurement of elemental carbon

    Energy Technology Data Exchange (ETDEWEB)

    Lavanchy, V.M.H. [Bern Univ. (Switzerland); Baltensperger, U.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    A thermal method was developed to measure the organic carbon (OC) and elemental carbon (EC) content of atmospheric aerosols. OC is first oxidized under an O{sub 2} flow during a precombustion step and measured with an Non-Dispersive Infrared Analyzer (NDIR). The remaining carbon, defined as EC, is then oxidized at 650{sup o}C. (author) 1 fig., 1 tab., 3 refs.

  17. The Impact of Transport Mode and Carbon Policy on Low-Carbon Retailer

    Directory of Open Access Journals (Sweden)

    Yi Zheng

    2015-01-01

    Full Text Available Low-carbon retail has become a strategic target for many developed and developing economies. This study discusses the impact of transport mode and carbon policy on achieving this objective. We investigated the retailer transportation mode, pricing, and ordering strategy, which all consider carbon-sensitive demand under the carbon cap-and-trade policy. We analyzed the optimal decision of retailer and their maximum profit affected by transport mode and cap-and-trade policy parameters. Results show that the two elements (cap-and-trade policy and consumer low-carbon awareness could encourage the retailer to choose low-carbon transportation. The two elements also influence the profit and optimal decision of retailer. Finally, a numerical example is presented to illustrate the applicability of the model.

  18. Characterization of the preferential movement of elements during sputtering of binary targets

    International Nuclear Information System (INIS)

    Davarya, F.

    1982-01-01

    The knowledge of the physics of ion bombardment effects has matured considerably during the last decade. This has generated an ever increasing number of new applications and the subsequent need for better understanding of the collisional interaction, especially in bombardment of multicomponent materials. This research investigates the near-surface composition changes due to the preferential movement of target elements in binary systems under ion bombardment. The Monte-Carlo code EVOLVE, which has been developed at the University of Maryland for ion transport studies, has been utilized for these investigations. The effects of differences in three key parameters, surface binding energy, displacement energy, and mass of target elements have been studied. It has been observed that in the absence of any binding energy differences, the effect of the mass difference of target elements is contrary to the previously commonly held belief that the lighter target elements tend to be preferentially implanted inward relative to the heavier elements. Cases are presented where preferential inward movement of the heavier elements were observed. Further studies were carried out using EVOLVE and it has been observed that the heavier elements, while having shorter path length relative to the lighter elements, have a longer projected penetration depth. Due to the lack of standard reference materials (SRM's) for studing ion bombardment effects, quantitative comparison of results obtained using different techniques has been unreliable. In an effort to help resolve this need, multilayered thin-film structures (prepared for SRM use) have been studied using both experimental techniques and computer simulaton. The characteristics of those structures which are useful for SMR application, such as layer thickness, layer periodicity, and interface widths are presented

  19. [Ultra-Fine Pressed Powder Pellet Sample Preparation XRF Determination of Multi-Elements and Carbon Dioxide in Carbonate].

    Science.gov (United States)

    Li, Xiao-li; An, Shu-qing; Xu, Tie-min; Liu, Yi-bo; Zhang, Li-juan; Zeng, Jiang-ping; Wang, Na

    2015-06-01

    The main analysis error of pressed powder pellet of carbonate comes from particle-size effect and mineral effect. So in the article in order to eliminate the particle-size effect, the ultrafine pressed powder pellet sample preparation is used to the determination of multi-elements and carbon-dioxide in carbonate. To prepare the ultrafine powder the FRITSCH planetary Micro Mill machine and tungsten carbide media is utilized. To conquer the conglomeration during the process of grinding, the wet grinding is preferred. The surface morphology of the pellet is more smooth and neat, the Compton scatter effect is reduced with the decrease in particle size. The intensity of the spectral line is varied with the change of the particle size, generally the intensity of the spectral line is increased with the decrease in the particle size. But when the particle size of more than one component of the material is decreased, the intensity of the spectral line may increase for S, Si, Mg, or decrease for Ca, Al, Ti, K, which depend on the respective mass absorption coefficient . The change of the composition of the phase with milling is also researched. The incident depth of respective element is given from theoretical calculation. When the sample is grounded to the particle size of less than the penetration depth of all the analyte, the effect of the particle size on the intensity of the spectral line is much reduced. In the experiment, when grounded the sample to less than 8 μm(d95), the particle-size effect is much eliminated, with the correction method of theoretical α coefficient and the empirical coefficient, 14 major, minor and trace element in the carbonate can be determined accurately. And the precision of the method is much improved with RSD element, the fluorescence yield is low and the interference is serious. With the manual multi-layer crystal PX4, coarse collimator, empirical correction, X-ray spectrometer can be used to determine the carbon dioxide in the carbonate

  20. A real-time, wearable elemental carbon monitor for use in underground mines

    International Nuclear Information System (INIS)

    Takiff, L.; Aiken, G.

    2010-01-01

    A real-time, wearable elemental carbon monitor has been developed to determines the exposure of workers in underground mines to diesel particulate material (DPM). ICx Technologies designed the device in an effort to address the health hazards associated with DPM exposure. Occupational exposure to DPM in underground metal and nonmetal mines is regulated by the Mine Safety and Health Administration. The most common method of measuring exposure to elemental or total carbon nanoparticles involves capturing the particles on a filter followed by a thermo-optical laboratory analysis, which integrates the exposure spatially and in time. The ICx monitor is based on a design developed and tested by the National Institute of Occupational Safety and Health (NIOSH). The ICx monitor uses a real-time particle capture and light transmission method to yield elemental carbon values that are displayed for the wearer and are stored internally in a compact device. The ICx monitoring results were found to be in good agreement with the established laboratory method (NIOSH Method 5040) for elemental carbon emissions from a diesel engine. The monitors are compact and powered by a rechargeable lithium-ion battery. Examples of DPM monitoring in mines demonstrated how the real-time data can be more useful that time-averaged results. The information can be used to determine ventilation rates needed at any given location to lower the DPM concentrations.15 refs., 6 figs.

  1. A real-time, wearable elemental carbon monitor for use in underground mines

    Energy Technology Data Exchange (ETDEWEB)

    Takiff, L. [ICx Technologies, Cambridge, MA (United States); Aiken, G. [ICx Technologies, Albuquerque, NM (United States)

    2010-07-01

    A real-time, wearable elemental carbon monitor has been developed to determines the exposure of workers in underground mines to diesel particulate material (DPM). ICx Technologies designed the device in an effort to address the health hazards associated with DPM exposure. Occupational exposure to DPM in underground metal and nonmetal mines is regulated by the Mine Safety and Health Administration. The most common method of measuring exposure to elemental or total carbon nanoparticles involves capturing the particles on a filter followed by a thermo-optical laboratory analysis, which integrates the exposure spatially and in time. The ICx monitor is based on a design developed and tested by the National Institute of Occupational Safety and Health (NIOSH). The ICx monitor uses a real-time particle capture and light transmission method to yield elemental carbon values that are displayed for the wearer and are stored internally in a compact device. The ICx monitoring results were found to be in good agreement with the established laboratory method (NIOSH Method 5040) for elemental carbon emissions from a diesel engine. The monitors are compact and powered by a rechargeable lithium-ion battery. Examples of DPM monitoring in mines demonstrated how the real-time data can be more useful that time-averaged results. The information can be used to determine ventilation rates needed at any given location to lower the DPM concentrations.15 refs., 6 figs.

  2. Experience gained with the 3D machining of the W7-X HHF divertor target elements

    International Nuclear Information System (INIS)

    Junghanns, P.; Boscary, J.; Peacock, A.

    2015-01-01

    Highlights: • The Wendelstein 7-X surface of the actively cooled divertor is built up of 890 individually 3D machined target elements. • To date 300 target elements have been 3D machined with an accuracy of ±0.015 mm. • Copper discovered on the surface of few elements is no risk to operation. - Abstract: The high heat flux (HHF) divertor of W7-X consists of 100 target modules assembled from 890 actively water-cooled target elements protected with CFC tiles. The divertor surface will be built up of individually 3D machined target elements with 89 individual element types. To date 300 of the 890 target elements have been 3D machined with a very good accuracy. To achieve this successful result, a prototyping phase has been conducted to qualify the manufacturing route and to define the acceptance criteria with measures taken to minimize the risk of unacceptable damage during the manufacturing. After the 3D-machining, during the incoming inspection, copper infiltration from the interface between the CFC tiles and the CuCrZr heat sink to the plasma facing surface was detected in a small number of elements.

  3. 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.

  4. 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.

  5. Elemental carbon exposure at residence and survival after acute myocardial infarction.

    Science.gov (United States)

    von Klot, Stephanie; Gryparis, Alexandros; Tonne, Cathryn; Yanosky, Jeffrey; Coull, Brent A; Goldberg, Robert J; Lessard, Darleen; Melly, Steven J; Suh, Helen H; Schwartz, Joel

    2009-07-01

    Particulate air pollution has been consistently related to cardiovascular mortality. Some evidence suggests that particulate matter may accelerate the atherosclerotic process. Effects of within-city variations of particulate air pollution on survival after an acute cardiovascular event have been little explored. We conducted a cohort study of hospital survivors of acute myocardial infarction (MI) from the Worcester, MA, metropolitan area to investigate the long-term effects of within-city variation in traffic-related air pollution on mortality. The study builds on an ongoing community-wide investigation examining changes over time in MI incidence and case-fatality rates. We included confirmed cases of MI in 1995, 1997, 1999, 2001, and 2003. Long-term survival status was ascertained through 2005. A validated spatiotemporal land use regression model for traffic-related air pollution was developed and annual averages of elemental carbon at residence estimated. The effect of estimated elemental carbon on the long-term mortality of patients discharged after MI was analyzed using a Cox proportional hazards model, controlling for a variety of demographic, medical history, and clinical variables. Of the 3895 patients with validated MI, 44% died during follow-up. Exposure to estimated elemental carbon in the year of entry into the study was 0.44 microg/m on average. All-cause mortality increased by 15% (95% confidence interval = 0.03%-29%) per interquartile range increase in estimated yearly elemental carbon (0.24 microg/m) after the second year of survival. No association between traffic-related pollution and all-cause mortality was observed during the first 2 years of follow-up. Chronic traffic-related particulate air pollution is associated with increased mortality in hospital survivors of acute MI after the second year of survival.

  6. Finite element modeling of single-walled carbon nanotubes with introducing a new wall thickness

    International Nuclear Information System (INIS)

    Jalalahmadi, B; Naghdabadi, R

    2007-01-01

    A three-dimensional finite element (FE) model for armchair, zigzag and chiral single-walled carbon nanotubes (SWCNTs) is proposed. By considering the covalent bonds as connecting elements between carbon atoms, a nanotube is simulated as a space frame-like structure. Here, the carbon atoms act as joints of the connecting elements. To create the FE models, nodes are placed at the locations of carbon atoms and the bonds between them are modeled using three-dimensional elastic beam elements. Using Morse atomic potential, the elastic moduli of beam elements are obtained via considering a linkage between molecular and continuum mechanics. Also, a new wall thickness ( bond diameter) equal to 0.1296 nm is introduced. In order to demonstrate the applicability of FE model and new wall thickness, the influence of tube wall thickness, diameter and chirality on the Young's modulus of SWCNTs is investigated. It is found that the choice of wall thickness significantly affects the calculation of Young's modulus. For the values of wall thickness used in the literature, the Young's moduli are estimated which agree very well with the corresponding theoretical results and experimental measurements. We also investigate the dependence of elastic moduli on diameter and chirality of the nanotube. The larger tube diameter, the higher Young's modulus of SWCNT. The Young's modulus of chiral SWCNTs is found to be generally larger than that of armchair and zigzag SWCNTs. The presented results demonstrate that the proposed FE model and wall thickness may provide a valuable tool for studying the mechanical behavior of carbon nanotubes and their application in nano-composites

  7. Elemental Technologies for Lead-Bismuth Spallation Target System in J-PARC

    International Nuclear Information System (INIS)

    Obayashi, H.; Yamaguchi, K.; Saito, S.; Sugawara, T.; Takei, H.; Sasa, T.

    2015-01-01

    Japan Atomic Energy Agency (JAEA) has been researching and developing an Accelerator-Driven System (ADS) as a dedicated system for the transmutation of long-lived radioactive nuclides. The ADS proposed by JAEA uses the lead-bismuth eutectic (LBE) alloy as a spallation target material and a coolant. In the various R and D for ADS, construction of the Transmutation Experimental Facility (TEF) is planned under the framework of the J-PARC project as a preceding step before the construction of demonstrative ADS. In this R and D, TEF is considered for the experimental investigation of the feasibility of the beam window, the structural materials, and to investigate the operation properties of the target system by using 400 MeV-250 kW proton beam. This target system is consisted of various elements and must be able to operate without troubles during an operation period of TEF facility. Furthermore, in the maintenance period after the operation, because the inside of a hot cell storing a target is exposed to strong radiations, all elements must be designed as remote control devices. In this study, the present conditions of the design and the result of performance test of each important elements were confirmed in the realisation of the LBE target system, such as the monitoring system of flow rate by using the ultrasonic method, the heater system with the metallic heat insulator joined to a flow channel of LBE, and the operability of remote handing. (authors)

  8. 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)

  9. Comparing the NIOSH Method 5040 to a Diesel Particulate Matter Meter for Elemental Carbon

    Science.gov (United States)

    Ayers, David Matthew

    Introduction: The sampling of elemental carbon has been associated with monitoring exposures in the trucking and mining industries. Recently, in the field of engineered nanomaterials, single wall and muti-wall carbon nanotubes (MWCNTs) are being produced in ever increasing quantities. The only approved atmospheric sampling for multi-wall carbon nanotubes in NIOSH Method 5040. These results are accurate but can take up to 30 days for sample results to be received. Objectives: Compare the results of elemental carbon sampling from the NIOSH Method 5040 to a Diesel Particulate Matter (DPM) Meter. Methods: MWCNTs were transferred and weighed between several trays placed on a scale. The NIOSH Method 5040 and DPM sampling train was hung 6 inches above the receiving tray. The transferring and weighing of the MWCNTs created an aerosol containing elemental carbon. Twenty-one total samples using both meters type were collected. Results: The assumptions for a Two-Way ANOVA were violated therefore, Mann-Whitney U Tests and a Kruskal-Wallis Test were performed. The hypotheses for both research questions were rejected. There was a significant difference in the EC concentrations obtained by the NIOSH Method 5040 and the DPM meter. There were also significant differences in elemental carbon level concentrations when sampled using a DPM meter versus a sampling pump based upon the three concentration levels (low, medium and high). Conclusions: The differences in the EC concentrations were statistically significant therefore, the two methods (NIOSH Method 5040 and DPM) are not the same. The NIOSH Method 5040 should continue to be the only authorized method of establishing an EC concentration for MWCNTs until a MWCNT specific method or an instantaneous meter is invented.

  10. 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.

  11. 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.)

  12. 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.

  13. Extraction of transplutonium elements from carbonate solutions by alkylpyrocatechol

    International Nuclear Information System (INIS)

    Karalova, Z.K.; Myasoedov, B.F.; Rodionova, L.M.; Kuznetsova, V.S.

    1983-01-01

    Extraction of americium, berkelium as well as Ce, Eu, Th, U, Zr, Cs, Fe with solution of 4(α, α-dioctylethyl)pyrocatechol (DOP) in toluene from carbonate solutions to determine conditions of their separation has been studied. It is established that americium extraction is quite sensitive to the changes of potassium carbonate concentration. The maximum extraction of americium (R >90%) is observed in the case of 0.1-0.5 mol/l of K 2 CO 3 solutions and the minimum one (R=2.5%) - in the case of 8 mol/l K 2 CO 3 . Americium extraction increases sharply when sodium hydroxide is introduced in carbonate solutions. It is shown that varying sodium hydroxide concentration it is possible to achieve qualitative extraction of americium even from saturated solution of potassium carbonate. Reextraction of TPE is easily realized with 3 mol/l HCl solution. The system K 2 CO 3 (KOH)-DOP proved to be perspective for Am separation from Bk, Ce, Cs, actinoid elements as well as from Fe

  14. Monitoring of organic and elemental carbon (OC/EC) in the atmospheric aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, A.; Fuchs, J.; Jaeschke, W.; Weingartner, E.; Baltensperger, U.

    2003-03-01

    A new instrument for the measurement of ambient carbonaceous aerosol concentrations is described, which enables discrimination between organic and elemental carbon on a semi-continuous basis. (author)

  15. 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.

  16. 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

  17. Quantitative evaluation of potential irradiation geometries for carbon-ion beam grid therapy.

    Science.gov (United States)

    Tsubouchi, Toshiro; Henry, Thomas; Ureba, Ana; Valdman, Alexander; Bassler, Niels; Siegbahn, Albert

    2018-03-01

    Radiotherapy using grids containing cm-wide beam elements has been carried out sporadically for more than a century. During the past two decades, preclinical research on radiotherapy with grids containing small beam elements, 25 μm-0.7 mm wide, has been performed. Grid therapy with larger beam elements is technically easier to implement, but the normal tissue tolerance to the treatment is decreasing. In this work, a new approach in grid therapy, based on irradiations with grids containing narrow carbon-ion beam elements was evaluated dosimetrically. The aim formulated for the suggested treatment was to obtain a uniform target dose combined with well-defined grids in the irradiated normal tissue. The gain, obtained by crossfiring the carbon-ion beam grids over a simulated target volume, was quantitatively evaluated. The dose distributions produced by narrow rectangular carbon-ion beams in a water phantom were simulated with the PHITS Monte Carlo code. The beam-element height was set to 2.0 cm in the simulations, while the widths varied from 0.5 to 10.0 mm. A spread-out Bragg peak (SOBP) was then created for each beam element in the grid, to cover the target volume with dose in the depth direction. The dose distributions produced by the beam-grid irradiations were thereafter constructed by adding the dose profiles simulated for single beam elements. The variation of the valley-to-peak dose ratio (VPDR) with depth in water was thereafter evaluated. The separation of the beam elements inside the grids were determined for different irradiation geometries with a selection criterion. The simulated carbon-ion beams remained narrow down to the depths of the Bragg peaks. With the formulated selection criterion, a beam-element separation which was close to the beam-element width was found optimal for grids containing 3.0-mm-wide beam elements, while a separation which was considerably larger than the beam-element width was found advantageous for grids containing 0.5-mm

  18. Wet scavenging of organic and elemental carbon during summer monsoon and winter monsoon seasons

    Science.gov (United States)

    Sonwani, S.; Kulshrestha, U. C.

    2017-12-01

    In the era of rapid industrialization and urbanization, atmospheric abundance of carbonaceous aerosols is increasing due to more and more fossil fuel consumption. Increasing levels of carbonaceous content have significant adverse effects on air quality, human health and climate. The present study was carried out at Delhi covering summer monsoon (July -Sept) and winter monsoon (Dec-Jan) seasons as wind and other meteorological factors affect chemical composition of precipitation in different manner. During the study, the rainwater and PM10 aerosols were collected in order to understand the scavenging process of elemental and organic carbon. The Rain water samples were collected on event basis. PM10 samples were collected before rain (PR), during rain (DR) and after rain (AR) during 2016-2017. The collected samples were analysed by the thermal-optical reflectance method using IMPROVE-A protocol. In PM10, the levels of organic carbon (OC) and its fractions (OC1, OC2, OC3 and OC4) were found significantly lower in the AR samples as compared to PR and DR samples. A significant positive correlation was noticed between scavenging ratios of organic carbon and rain intensity indicating an efficient wet removal of OC. In contrast to OCs, the levels of elemental carbon and its fractions (EC1, EC2, and EC3) in AR were not distinct during PR and DR. The elemental carbon showed very week correlation with rain intensity in Delhi region which could be explained on the basis of hydrophobic nature of freshly emitted carbon soot. The detailed results will be discussed during the conference.

  19. Modelling of single walled carbon nanotube cylindrical structures with finite element method simulations

    Science.gov (United States)

    Günay, E.

    2016-04-01

    In this study, the modulus of elasticity and shear modulus values of single-walled carbon nanotubes SWCNTs were modelled by using both finite element method and the Matlab code. Initially, cylindrical armchair and zigzag single walled 3D space frames were demonstrated as carbon nanostructures. Thereafter, macro programs were written by the Matlab code producing the space truss for zigzag and armchair models. 3D space frames were introduced to the ANSYS software and then tension, compression and additionally torsion tests were performed on zigzag and armchair carbon nanotubes with BEAM4 element in obtaining the exact values of elastic and shear modulus values. In this study, two different boundary conditions were tested and especially used in torsion loading. The equivalent shear modulus data was found by averaging the corresponding values obtained from ten different nodal points on the nanotube path. Finally, in this study it was determined that the elastic constant values showed proportional changes by increasing the carbon nanotube diameters up to a certain level but beyond this level these values remained stable.

  20. Modelling of single walled carbon nanotube cylindrical structures with finite element method simulations

    International Nuclear Information System (INIS)

    Günay, E.

    2016-01-01

    In this study, the modulus of elasticity and shear modulus values of single-walled carbon nanotubes SWCNTs were modelled by using both finite element method and the Matlab code. Initially, cylindrical armchair and zigzag single walled 3D space frames were demonstrated as carbon nanostructures. Thereafter, macro programs were written by the Matlab code producing the space truss for zigzag and armchair models. 3D space frames were introduced to the ANSYS software and then tension, compression and additionally torsion tests were performed on zigzag and armchair carbon nanotubes with BEAM4 element in obtaining the exact values of elastic and shear modulus values. In this study, two different boundary conditions were tested and especially used in torsion loading. The equivalent shear modulus data was found by averaging the corresponding values obtained from ten different nodal points on the nanotube path. Finally, in this study it was determined that the elastic constant values showed proportional changes by increasing the carbon nanotube diameters up to a certain level but beyond this level these values remained stable.

  1. Modelling of single walled carbon nanotube cylindrical structures with finite element method simulations

    Energy Technology Data Exchange (ETDEWEB)

    Günay, E. [Gazi University, Mechanical Engineering Department, 06570, Ankara (Turkey)

    2016-04-21

    In this study, the modulus of elasticity and shear modulus values of single-walled carbon nanotubes SWCNTs were modelled by using both finite element method and the Matlab code. Initially, cylindrical armchair and zigzag single walled 3D space frames were demonstrated as carbon nanostructures. Thereafter, macro programs were written by the Matlab code producing the space truss for zigzag and armchair models. 3D space frames were introduced to the ANSYS software and then tension, compression and additionally torsion tests were performed on zigzag and armchair carbon nanotubes with BEAM4 element in obtaining the exact values of elastic and shear modulus values. In this study, two different boundary conditions were tested and especially used in torsion loading. The equivalent shear modulus data was found by averaging the corresponding values obtained from ten different nodal points on the nanotube path. Finally, in this study it was determined that the elastic constant values showed proportional changes by increasing the carbon nanotube diameters up to a certain level but beyond this level these values remained stable.

  2. Neutron energy spectra produced by α-bombardment of light elements in thick targets

    International Nuclear Information System (INIS)

    Jacobs, G.J.H.

    1982-01-01

    The aim of the work, presented in this thesis, is to determine energy spectra of neutrons produced by α-particle bombardment of thick targets containing light elements. These spectra are required for nuclear waste management. The set-up of the neutron spectrometer is described, and its calibration discussed. Absolute efficiencies were determined at various neutron energies, using monoenergetic neutrons produced with the Van de Graaff accelerator in pulsed mode. The additional calibration of the neutron spectrometer as proton-recoil spectrometer was carried out primarily for future applications in measurements where no pulsed neutron source is available or the neutron flux density is too low. The basis for an accurate uncertainty analysis is made by the determination of the covariance matrix for the uncertainties in the efficiencies. The determination of the neutron energy spectra from time-of-flight and from proton-recoil measurements is described. A comparison of the results obtained from the two different types of measurements is made. The experimentally determined spectra were compared with spectra calculated from stopping powers and theoretically determined cross sections. These cross sections were calculated from optical model parameters and level parameters using the Hauser-Feshbach formalism. Measurements were carried out on thick targets of silicon, aluminium, magnesium, carbon, boron nitride, calcium fluoride, aluminium oxide, silicon oxide and uranium oxide at four different α-particle energies. (Auth.)

  3. Design improvement of the target elements of Wendelstein 7-X divertor

    International Nuclear Information System (INIS)

    Boscary, J.; Peacock, A.; Friedrich, T.; Greuner, H.; Böswirth, B.; Tittes, H.; Schulmeyer, W.; Hurd, F.

    2012-01-01

    Highlights: ► Improvement of the cooling structure design. ► Improvement of the CFC tile arrangement at the element end. ► Design and fabrication validated with high heat flux testing. ► Selected solution removes stationary heat load of 5 MW/m 2 and 2 MW/m 2 on the top and on the side facing the pumping gap of the element, respectively. - Abstract: The actively cooled high-heat flux divertor of the Wendelstein 7-X stellarator consists of individual target elements made of a water-cooled CuCrZr copper alloy heat sink armored with CFC tiles. The so-called “bi-layer” technology developed in collaboration with the company Plansee for the bonding of the tiles onto the heat sink has reliably demonstrated the removal of the specified heat load of 10 MW/m 2 in the central area of the divertor. However, due to geometrical constraints, the loading performance at the ends of the elements is reduced compared to the central part. Design modifications compatible with industrial processes have been made to improve the cooling capabilities at this location. These changes have been validated during test campaigns of full-scale prototypes carried out in the neutral beam test facility GLADIS. The tested solution can remove reliably the stationary heat load of 5 MW/m 2 and 2 MW/m 2 on the top and on the side of the element, respectively. The results of the testing allowed the release of the design and fabrication processes for the next manufacturing phase of the target elements.

  4. 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

  5. High heat flux tests of the WENDELSTEIN 7-X pre-series target elements

    International Nuclear Information System (INIS)

    Greuner, H.; Boeswirth, B.; Boscary, J.; Plankensteiner, A.; Schedler, B.

    2007-01-01

    The high heat flux (HHF) testing of WENDELSTEIN 7-X pre-series target elements is an indispensable step in the qualification of the manufacturing process. A set of 20 full scale pre-series elements was manufactured by PLANSEE SE to validate the materials and manufacturing technologies prior to the start of the series production. The HHF tests were performed in the ion beam test facility GLADIS. All actively water-cooled elements were tested for about 100 cycles at 10 MW/m 2 (10-15 s pulse duration). Several elements were loaded with even higher cycle numbers (up to 1000) and heat loads up to 24 MW/m 2 . Hot spots were, observed at the edges of several tiles during the HHF tests indicating local bonding problems of the CFC. The thermo-mechanical behaviour under HHF loading has been evaluated and compared to the FEM predictions. The measured temperatures and strains confirm the chosen FEM approach. This allows a component optimisation to achieve a successful series production of the W7-X divertor target elements

  6. Peculiarities of extraction of carbonate complexes of trivalent transplutonium elements by alkylpyrocatechins

    International Nuclear Information System (INIS)

    Karalova, Z.K.; Bukina, T.I.; Myasoedov, B.F.; Fedorov, L.A.; Sokolovskij, S.A.

    1987-01-01

    Extraction of trivalent americium, curium, californium and europium by technical mixture of mono- and didecylpyrocatechin (TAP) in various diluents from carbonate solutions is investigated. Effect of many factors (pH, K 2 CO 3 concentration, TAP, metal; the time of phase contact) on the completeness of element isolation and separation is clarified. It is ascertained that the elements listed are quantitatively extracted by TAP solution in toluene and cyclohexane in the range of K 2 CO 3 concentrations from 0.25 to 1.5 mol/l. The difference in americium and curium distribution coefficient during their extraction by TAP from 0.25 mol/l of K 2 CO 3 solution is detected. Separation coefficients of the pair increase with the increase of carbonate solution pH. The separation can be improved at the stage of element reextraction by the mixture of K 2 CO 3 and DTPA or EDTA from alkylpyrocatechin, sunce rate constants of americium and curium reextraction differ greatly. Using 13 C NMR the composition of compounds in organic phase on the basis of 4-(α, α-dioctylethyl)pyrocatechin is investigated

  7. Nonvolatile Memory Elements Based on the Intercalation of Organic Molecules Inside Carbon Nanotubes

    Science.gov (United States)

    Meunier, Vincent; Kalinin, Sergei V.; Sumpter, Bobby G.

    2007-02-01

    We propose a novel class of nonvolatile memory elements based on the modification of the transport properties of a conducting carbon nanotube by the presence of an encapsulated molecule. The guest molecule has two stable orientational positions relative to the nanotube that correspond to conducting and nonconducting states. The mechanism, governed by a local gating effect of the molecule on the electronic properties of the nanotube host, is studied using density functional theory. The mechanisms of reversible reading and writing of information are illustrated with a F4TCNQ molecule encapsulated inside a metallic carbon nanotube. Our results suggest that this new type of nonvolatile memory element is robust, fatigue-free, and can operate at room temperature.

  8. Element fractionation by sequential extraction in a soil with high carbonate content

    International Nuclear Information System (INIS)

    Sulkowski, Margareta; Hirner, Alfred V.

    2006-01-01

    The influence of carbonate and other buffering substances in soils on the results of a 3-step sequential extraction procedure (BCR) used for metal fractionation was investigated. Deviating from the original extraction scheme, where the extracts are analysed only for a limited number of metals, almost all elements in the soils were quantified by X-ray fluorescence spectroscopy, in the initial samples as well as in the residues of all extraction steps. Additionally, the mineral contents were determined by X-ray diffractometry. Using this methodology, it was possible to correlate changes in soil composition caused by the extraction procedure with the release of elements. Furthermore, the pH values of all extracts were monitored, and certain extraction steps were repeated until no significant pH-rise occurred. A soil with high dolomite content (27%) and a carbonate free soil were extracted. Applying the original BCR-sequence to the calcareous soil, carbonate was found in the residues of the first two steps and extract pH-values rose by around two units in the first and second step, caused mainly by carbonate dissolution. This led to wrong assignment of the carbonate elements Ca, Mg, Sr, Ba, and also to decreased desorption and increased re-adsorption of ions in those steps. After repetition of the acetic acid step until extract pH remained low, the carbonate was completely destroyed and the distributions of the elements Ca, Mg, Sr, Ba as well as those of Co, Ni, Cu, Zn and Pb were found to be quite different to those determined in the original extraction. Furthermore, it could be shown that the effectiveness of the reduction process in step two was reduced by increasing pH: Fe oxides were not significantly attacked by the repeated acetic acid treatments, but a 10-fold amount of Fe was mobilized by hydroxylamine hydrochloride after complete carbonate destruction. On the other hand, only small amounts of Fe were released anyway. Even repeated reduction steps did not

  9. Preparation of self-supporting thin metal target films

    International Nuclear Information System (INIS)

    Wang Xiuying; Ge Suxian; Yin Jianhua; Yin Xu; Jin Genming

    1989-01-01

    The preparation method and equipment for thin metal self-supporting target without oil contamination are described. The influence of target films contaminated by oil vapor on accuracy of nuclear-physics experimental data are also discussed. The analytical results on carbon content in the prepared films of three elements show that the equipment is very effective for eliminating contamination

  10. Development of carbon/carbon composite control rod for HTTR. 1. Preparation of elements and their fracture tests

    International Nuclear Information System (INIS)

    Eto, Motokuni; Ishiyama, Shintaro; Ugachi, Hirokazu

    1996-08-01

    For the High Temperature Engineering Test Reactor(HTTR) the control rod sleeve is made of Alloy 800H for which a particular process is imposed when the reactor needs to be scrammed. The less restricted operation of the reactor would be attained if there would be the control rod more resistant to high temperature and neutron irradiation. This report summarizes the results which have been obtained as of March 1996 in the course of the development of the C/C composite control rod. Materials used were pitch- or PAN-based fiber-reinforced 2-dimensional carbon composites, from which preforms of the elements of a control rod were fabricated. The preforms were carbonized at 1000degC after being impregnated with pitch. Then they were graphitized at 3000degC, followed by a purification treatment with halogen. The elements included the pellet holder, lace truck and pin. The pin was fabricated by the fiber laminating technique. A control rod is to consist of pellet holders which are connected by the lace trucks with pins. Various strength tests were carried out on these elements. An irradiation of the elements made of PAN-based material was performed in JRR-3 at 900±50degC to a neutron fluence of 1x10 25 n/m 2 (E>29fJ). As for the strength tests on the elements, there were some differences between PAN- and pitch-based composites: In general, elements made of PAN-based composite showed the more plastic behavior before they fractured, whereas those of pitch-based material behaved in the more brittle manner. Fracture tests of the irradiated elements showed that fracture load and fracture displacement enough for assuring the integrity of the control rod structure were maintained even after the irradiation. It was also found that if the applied load was parallel to the fiber felt plane both fracture load and strain increased, whereas the load increase and strain decrease were observed for the applied load against the plane. (J.P.N.)

  11. Development of carbon/carbon composite control rod for HTTR. 1. Preparation of elements and their fracture tests

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Motokuni; Ishiyama, Shintaro; Ugachi, Hirokazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-08-01

    For the High Temperature Engineering Test Reactor(HTTR) the control rod sleeve is made of Alloy 800H for which a particular process is imposed when the reactor needs to be scrammed. The less restricted operation of the reactor would be attained if there would be the control rod more resistant to high temperature and neutron irradiation. This report summarizes the results which have been obtained as of March 1996 in the course of the development of the C/C composite control rod. Materials used were pitch- or PAN-based fiber-reinforced 2-dimensional carbon composites, from which preforms of the elements of a control rod were fabricated. The preforms were carbonized at 1000degC after being impregnated with pitch. Then they were graphitized at 3000degC, followed by a purification treatment with halogen. The elements included the pellet holder, lace truck and pin. The pin was fabricated by the fiber laminating technique. A control rod is to consist of pellet holders which are connected by the lace trucks with pins. Various strength tests were carried out on these elements. An irradiation of the elements made of PAN-based material was performed in JRR-3 at 900{+-}50degC to a neutron fluence of 1x10{sup 25} n/m{sup 2} (E>29fJ). As for the strength tests on the elements, there were some differences between PAN- and pitch-based composites: In general, elements made of PAN-based composite showed the more plastic behavior before they fractured, whereas those of pitch-based material behaved in the more brittle manner. Fracture tests of the irradiated elements showed that fracture load and fracture displacement enough for assuring the integrity of the control rod structure were maintained even after the irradiation. It was also found that if the applied load was parallel to the fiber felt plane both fracture load and strain increased, whereas the load increase and strain decrease were observed for the applied load against the plane. (J.P.N.)

  12. Segregation of Elements in Continuous Cast Carbon Steel Billets Designated for Long Products

    Directory of Open Access Journals (Sweden)

    Hutny A. M.

    2016-12-01

    Full Text Available This article presents research results concerning designation of the scope of segregation of elements by analysing the ingot, designated for hot rolling of long products. The research tests were performed under industrial conditions, during continuous casting production cycle of high carbon steels. From cc ingots with square cross-section of 160 mm samples having the length of 400 mm were collected, out of which two samples were cut up, the so-called templates with the thickness of 20 mm. Segregation of elements was determined based on the quantitative analysis of results performed by using spark spectrometry pursuant to PN-H-04045. Changes in concentrations of elements were analysed along the line, which join the opposite sides of the sample in their half length and pass through the geometric centre of the square cross-section. In the further course of the research study, there was also determined the segregation along perpendicular line up to the surface connecting the core of the cross-section with lateral plane. Designations of element contents were performed at points distanced from each other by approx. 10 mm and situated on the lines. There was found segregation of carbon, sulphur and phosphorus.

  13. Addition of granular activated carbon and trace elements to favor volatile fatty acid consumption during anaerobic digestion of food waste.

    Science.gov (United States)

    Capson-Tojo, Gabriel; Moscoviz, Roman; Ruiz, Diane; Santa-Catalina, Gaëlle; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

    2018-07-01

    The effect of supplementing granular activated carbon and trace elements on the anaerobic digestion performance of consecutive batch reactors treating food waste was investigated. The results from the first batch suggest that addition of activated carbon favored biomass acclimation, improving acetic acid consumption and enhancing methane production. Adding trace elements allowed a faster consumption of propionic acid. A second batch proved that a synergy existed when activated carbon and trace elements were supplemented simultaneously. The degradation kinetics of propionate oxidation were particularly improved, reducing significantly the batch duration and improving the average methane productivities. Addition of activated carbon favored the growth of archaea and syntrophic bacteria, suggesting that interactions between these microorganisms were enhanced. Interestingly, microbial analyses showed that hydrogenotrophic methanogens were predominant. This study shows for the first time that addition of granular activated carbon and trace elements may be a feasible solution to stabilize food waste anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. 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)

  15. 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.

  16. Fabrication and testing of W7-X pre-series target elements

    International Nuclear Information System (INIS)

    Boscary, J; Boeswirth, B; Greuner, H; Grigull, P; Missirlian, M; Plankensteiner, A; Schedler, B; Friedrich, T; Schlosser, J; Streibl, B; Traxler, H

    2007-01-01

    The assembly of the highly-loaded target plates of the WENDELSTEIN 7-X (W7-X) divertor requires the fabrication of 890 target elements (TEs). The plasma facing material is made of CFC NB31 flat tiles bonded to a CuCrZr copper alloy water-cooled heat sink. The elements are designed to remove a stationary heat flux and power up to 10 MW m -2 and 100 kW, respectively. Before launching the serial fabrication, pre-series activities aimed at qualifying the design, the manufacturing route and the non-destructive examinations (NDEs). High heat flux (HHF) tests performed on full-scale pre-series TEs resulted in an improvement of the design of the bond between tiles and heat sink to reduce the stresses during operation. The consequence is the fabrication of additional pre-series TEs to be tested in the HHF facility GLADIS. NDEs of this bond based on thermography methods are developed to define the acceptance criteria suitable for serial fabrication

  17. Moving finite element method for ICF target implosion

    Science.gov (United States)

    Furuta, J.; Kawata, S.; Niu, K.

    1985-03-01

    One dimensional hydrodynamic codes for the analysis of internal confinement fusion (ICF) target implosion which include various effects were developed, but most of them utilize the artificial viscosity (e.g., Von Neumann's viscosity) which cannot reveal accurately the shock waves. A gain of ICF target implosion is much due to the dissipation at the shock fronts, so it is necessary to express correctly the shock waves which are affected by the viscosity. The width of the shock waves is usually a few times as large as the length of mean free path, therefore the meshes for the shock waves must be set to about 10 to the 4th to 10 to the 5th power. It is a serious problem because of the computational memories or CPU time. In the moving finite element (MPE) method, both nodal amplitudes and nodal positions move continuously with time in such a way as to satisfy simultaneous ordinary differential equations (OPDs) which minimize partial differential equation (PDE) residuals.

  18. Comparison Between Elemental Carbon Measured Using Thermal-Optical Analysis and Black Carbon Measurements Using A Novel Cellphone-Based System

    Science.gov (United States)

    Ramanathan, N.; Khan, B.; Leong, I.; Lukac, M.

    2011-12-01

    Black carbon (BC) is produced through the incomplete combustion of fossil and solid fuels. Current BC emissions inventories have large uncertainties of factors of 2 or more due to sparse measurements and because BC is often emitted by local sources that vary over time and space (Bond et al, 2004). Those uncertainties are major sources of error in air pollution models. Emissions from a variety of improved cookstove/fuel/combustion conditions were collected on pre-conditioned 47 mm quartz-fiber filters and analyzed for organic carbon (OC) and elemental carbon (EC) using thermal-optical analysis (TOA). The samples were then analyzed for BC concentration by using cellphone-based instrumentation developed by Ramanathan et al., 2011. The cellphone-based monitoring system (CBMS) is a wireless, low-cost, low-power system that monitors BC emissions. The CBMS is comprised of an aerosol filter sampler containing a battery-powered air pump and a 25mm filter holder that draws air in through a quartz-fiber filter. As black carbon deposits increase, the filter darkens--the darkest color representing the highest loading. A cellphone photograph of the filter with the black carbon deposit is taken and relayed to an analytics unit for comparison to a reference scale to estimate airborne BC concentration. The BC concentration can then be compared to the thermally derived EC concentration. TOA was conducted on a Sunset Laboratory Dual Optics Carbon Analyzer using a modified version of the Birch and Cary (1996) NIOSH 5040 protocol. The dual-optical instrument permitted simultaneous monitoring of the transmission (TOT) and reflectance (TOR). 619 samples were collected; EC was obtained using NIOSH TOT and NIOSH TOR methods, and BC was obtained using the CBMS analytics unit. The mean BC value reported by the CBMS agrees within 20% of the reference values for EC, confirming the findings in Ramanathan et al. (2011) based on samples from India. Given this accuracy, we conclude that the CBMS

  19. Fluido-Dynamic and Electromagnetic Characterization of 3D Carbon Dielectrophoresis with Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Rodrigo Martinez-Duarte

    2008-12-01

    Full Text Available The following work presents the fluido-dynamic and electromagnetic characterization of an array of 3D electrodes to be used in high throughput and high efficiency Carbon Dielectrophoresis (CarbonDEP applications such as filters, continuous particle enrichment and positioning of particle populations for analysis. CarbonDEP refers to the induction of Dielectrophoresis (DEP by carbon surfaces. The final goal is, through an initial stage of modeling and analysis, to reduce idea-to-prototype time and cost of CarbonDEP devices to be applied in the health care field. Finite Element Analysis (FEA is successfully conducted to model flow velocity and electric fields established by polarized high aspect ratio carbon cylinders, and its planar carbon connecting leads, immersed in a water-based medium. Results demonstrate correlation between a decreasing flow velocity gradient and an increasing electric field gradient toward electrodes’ surfaces which is optimal for selected CarbonDEP applications. Simulation results are experimentally validated in the proposed applications.

  20. Evaluation of a two-step thermal method for separating organic and elemental carbon for radiocarbon analysis

    NARCIS (Netherlands)

    Dusek, U.; Monaco, M.; Prokopiou, M.; Gongriep, F.; Hitzenberger, R.; Meijer, H. A. J.; Rockmann, T.

    2014-01-01

    We thoroughly characterized a system for thermal separation of organic carbon (OC) and elemental carbon (EC) for subsequent radiocarbon analysis. Different organic compounds as well as ambient aerosol filter samples were introduced into an oven system and combusted to CO2 in pure O-2. The main

  1. 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

  2. The α-induced thick-target γ-ray yield from light elements

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, R. K. [Queen`s Univ., Kingston, ON (Canada). Dept. of Physics

    1994-10-01

    The α-induced thick-target γ-ray yield from light elements has been measured in the energy range 5.6 MeV ≤ Eα ≤ 10 MeV. The γ-ray yield for > 2.1 MeV from thick targets of beryllium, boron nitride, sodium fluoride, magnesium, aluminum and silicon were measured using the α-particle beam from the Lawrence Berkeley Laboratories 88 in. cyclotron. The elemental yields from this experiment were used to construct the α-induced direct production γ-ray spectrum from materials in the SNO detector, a large volume ultra-low background neutrino detector located in the Creighton mine near Sudbury, Canada. This background source was an order of magnitude lower than predicted by previous calculations. These measurements are in good agreement with theoretical calculations of this spectrum based on a statistical nuclear model of the reaction, with the gross high energy spectrum structure being reproduced to within a factor of two. Detailed comparison of experimental and theoretical excitation population distribution of several residual nuclei indicate the same level of agreement within experimental uncertainties.

  3. 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.

  4. Periodic Table Target: A Game that Introduces the Biological Significance of Chemical Element Periodicity

    Science.gov (United States)

    Sevcik, Richard S.; McGinty, Ragan L.; Schultz, Linda D.; Alexander, Susan V.

    2008-01-01

    Periodic Table Target, a game for middle school or high school students, familiarizes students with the form of the periodic table and the biological significance of different elements. The Periodic Table Target game board is constructed as a class project, and the game is played to reinforce the content. Students are assigned several elements…

  5. Polycyclic aromatic hydrocarbons, elemental and organic carbon emissions from tire-wear.

    Science.gov (United States)

    Aatmeeyata; Sharma, Mukesh

    2010-09-15

    Tire-wear is an important source of PAHs, elemental carbon (EC) and organic carbon (OC). The emissions of these pollutants have been studied in an experimental set-up, simulating a realistic road-tire interaction (summer tire-concrete road). The large particle non-exhaust emissions (LPNE; diameter greater than 10 microm) have been evaluated over 14,500 km run of the tire. An increasing linear trend with cumulative km run was observed for emissions of PAHs and carbon. Amongst PAHs in LPNE, pyrene has been observed to be the highest (30+/-4 mg kg(-1)) followed by benzo[ghi]perylene (17+/-2 mg kg(-1)). Different fractions of EC-OC for tire-wear have been analyzed, and unlike exhaust emissions, EC1 was observed to be 99% of EC whereas more than 70% of the OC was the high temperature carbon (OC3 and OC4). The overall emission factors (mass tire(-1) km(-1)) for PAHs, EC and OC from tire-wear are 378 ng tire(-1) km(-1), 1.46 mg tire(-1) km(-1) and 2.37 mg tire(-1) km(-1) for small cars. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Parallel measurements of organic and elemental carbon dry (PM1, PM2.5) and wet (rain, snow, mixed) deposition into the Baltic Sea.

    Science.gov (United States)

    Witkowska, Agnieszka; Lewandowska, Anita; Falkowska, Lucyna M

    2016-03-15

    Parallel studies on organic and elemental carbon in PM1 and PM2.5 aerosols and in wet deposition in various forms of its occurrence were conducted in the urbanised coastal zone of the Baltic Sea. The carbon load introduced into the sea water was mainly affected by the form of precipitation. Dry deposition load of carbon was on average a few orders of magnitude smaller than wet deposition. The suspended organic carbon was more effectively removed from the air with rain than snow, while an inverse relationship was found for elemental carbon. However the highest flux of water insoluble organic carbon was recorded in precipitation of a mixed nature. The atmospheric cleaning of highly dissolved organic carbon was observed to be the most effective on the first day of precipitation, while the hydrophobic elemental carbon was removed more efficiently when the precipitation lasted longer than a day. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Thermal design and analysis of the HTGR fuel element vertical carbonizing and annealing furnace

    International Nuclear Information System (INIS)

    Llewellyn, G.H.

    1977-06-01

    Computer analyses of the thermal design for the proposed HTGR fuel element vertical carbonizing and annealing furnace were performed to verify its capability and to determine the required power input and distribution. Although the furnace is designed for continuous operation, steady-state temperature distributions were obtained by assuming internal heat generation in the fuel elements to simulate their mass movement. The furnace thermal design, the analysis methods, and the results are discussed herein

  8. Implications of elevated CO2 on pelagic carbon fluxes in an Arctic mesocosm study – an elemental mass balance approach

    Directory of Open Access Journals (Sweden)

    J. Czerny

    2013-05-01

    Full Text Available Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budgets. In practice, attempts to budget mesocosm enclosures are often hampered by uncertainties in some of the measured pools and fluxes, in particular due to uncertainties in constraining air–sea gas exchange, particle sinking, and wall growth. In an Arctic mesocosm study on ocean acidification applying KOSMOS (Kiel Off-Shore Mesocosms for future Ocean Simulation, all relevant element pools and fluxes of carbon, nitrogen and phosphorus were measured, using an improved experimental design intended to narrow down the mentioned uncertainties. Water-column concentrations of particulate and dissolved organic and inorganic matter were determined daily. New approaches for quantitative estimates of material sinking to the bottom of the mesocosms and gas exchange in 48 h temporal resolution as well as estimates of wall growth were developed to close the gaps in element budgets. However, losses elements from the budgets into a sum of insufficiently determined pools were detected, and are principally unavoidable in mesocosm investigation. The comparison of variability patterns of all single measured datasets revealed analytic precision to be the main issue in determination of budgets. Uncertainties in dissolved organic carbon (DOC, nitrogen (DON and particulate organic phosphorus (POP were much higher than the summed error in determination of the same elements in all other pools. With estimates provided for all other major elemental pools, mass balance calculations could be used to infer the temporal development of DOC, DON and POP pools. Future elevated pCO2 was found to enhance net autotrophic community carbon

  9. Cis-regulatory element based targeted gene finding: genome-wide identification of abscisic acid- and abiotic stress-responsive genes in Arabidopsis thaliana.

    Science.gov (United States)

    Zhang, Weixiong; Ruan, Jianhua; Ho, Tuan-Hua David; You, Youngsook; Yu, Taotao; Quatrano, Ralph S

    2005-07-15

    A fundamental problem of computational genomics is identifying the genes that respond to certain endogenous cues and environmental stimuli. This problem can be referred to as targeted gene finding. Since gene regulation is mainly determined by the binding of transcription factors and cis-regulatory DNA sequences, most existing gene annotation methods, which exploit the conservation of open reading frames, are not effective in finding target genes. A viable approach to targeted gene finding is to exploit the cis-regulatory elements that are known to be responsible for the transcription of target genes. Given such cis-elements, putative target genes whose promoters contain the elements can be identified. As a case study, we apply the above approach to predict the genes in model plant Arabidopsis thaliana which are inducible by a phytohormone, abscisic acid (ABA), and abiotic stress, such as drought, cold and salinity. We first construct and analyze two ABA specific cis-elements, ABA-responsive element (ABRE) and its coupling element (CE), in A.thaliana, based on their conservation in rice and other cereal plants. We then use the ABRE-CE module to identify putative ABA-responsive genes in A.thaliana. Based on RT-PCR verification and the results from literature, this method has an accuracy rate of 67.5% for the top 40 predictions. The cis-element based targeted gene finding approach is expected to be widely applicable since a large number of cis-elements in many species are available.

  10. Identification of hookworm DAF-16/FOXO response elements and direct gene targets.

    Directory of Open Access Journals (Sweden)

    Xin Gao

    2010-08-01

    Full Text Available The infective stage of the parasitic nematode hookworm is developmentally arrested in the environment and needs to infect a specific host to complete its life cycle. The canine hookworm (Ancylostoma caninum is an excellent model for investigating human hookworm infections. The transcription factor of A. caninum, Ac-DAF-16, which has a characteristic fork head or "winged helix" DNA binding domain (DBD, has been implicated in the resumption of hookworm development in the host. However, the precise roles of Ac-DAF-16 in hookworm parasitism and its downstream targets are unknown. In the present study, we combined molecular techniques and bioinformatics to identify a group of Ac-DAF-16 binding sites and target genes.The DNA binding domain of Ac-DAF-16 was used to select genomic fragments by in vitro genomic selection. Twenty four bound genomic fragments were analyzed for the presence of the DAF-16 family binding element (DBE and possible alternative Ac-DAF-16 bind motifs. The 22 genes linked to these genomic fragments were identified using bioinformatics tools and defined as candidate direct gene targets of Ac-DAF-16. Their developmental stage-specific expression patterns were examined. Also, a new putative DAF-16 binding element was identified.Our results show that Ac-DAF-16 is involved in diverse biological processes throughout hookworm development. Further investigation of these target genes will provide insights into the molecular basis by which Ac-DAF-16 regulates its downstream gene network in hookworm infection.

  11. Development of highly heat-resistant target elements for fusion reactors; Entwicklung hochwaermebestaendiger Targetelemente fuer Fusionsreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Boscary, Jean; Stadler, R.; Greuner, H.; Smirnow, M.; Drescher, N.; Boeswirth, B.; Tretter, J.; Mendelevitch, B.

    2016-06-15

    The following topics are dealt with: Scientific and technical results for divertor components (''target elements'') of the Wendelstein 7-X facility, development of nondestructive test procedures at the cooling structures, development of an automatized procedure for the visual inspection, the ''scraper''-element. (HSI)

  12. Accurate determination of light elements by charged particle activation analysis

    International Nuclear Information System (INIS)

    Shikano, K.; Shigematsu, T.

    1989-01-01

    To develop accurate determination of light elements by CPAA, accurate and practical standardization methods and uniform chemical etching are studied based on determination of carbon in gallium arsenide using the 12 C(d,n) 13 N reaction and the following results are obtained: (1)Average stopping power method with thick target yield is useful as an accurate and practical standardization method. (2)Front surface of sample has to be etched for accurate estimate of incident energy. (3)CPAA is utilized for calibration of light element analysis by physical method. (4)Calibration factor of carbon analysis in gallium arsenide using the IR method is determined to be (9.2±0.3) x 10 15 cm -1 . (author)

  13. The Fourth Element Targeting hypothesis of Alzheimer’s disease pathogenesis and pathophysiology

    Directory of Open Access Journals (Sweden)

    Rodrigo O Kuljiš

    2010-11-01

    Full Text Available Despite well over a century of research on all forms of the disorder known as Alzheimer’s disease (AD, it is still not known whether the condition targets initially neurons, glial cells, other cellular elements in the brain, or components of cells, such as synapses, or molecules independently of their cellular compartmentalization, or otherwise (e.g. specific neuronal circuits. Multiple lines of highly suggestive but as yet insufficient experimental evidence are discussed here to formulate the hypothesis that AD results from primary (i.e. direct and initial or secondary targeting of what we designate as the Fourth Element Cell (4EC: a relatively recently identified type of brain cell that exhibits features in common with neurons (e.g. synapses, participation in glutamatergic and GABAergic neurotransmission, astrocytes, oligodendrocytes and their precursors, but is in other respects clearly distinct from all of them. The 4EC is proposed to be the main target of both: (1 converging insults (i.e. not true causes that over time cause sporadic forms of AD as postulated by the Danger Signal Hypothesis — which was not formulated with 4EC in mind — as well as (2 the causes of inherited (i.e. familial forms of neurodegeneration that resemble certain aspects of the clinical manifestations of sporadic AD.

  14. 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.

  15. Production of exotic, short lived carbon isotopes in ISOL-type facilities

    CERN Document Server

    Franberg, Hanna; Köster, Ulli; Ammann, Markus

    2008-01-01

    The beam intensities of short-lived carbon isotopes at Isotope Separation On-Line (ISOL) facilities have been limited in the past for technical reasons. The production of radioactive ion beams of carbon isotopes is currently of high interest for fundamental nuclear physics research. To produce radioactive ions a target station consisting of a target in a container connected to an ion source via a transfer line is commonly used. The target is heated to vaporize the product for transport. Carbon in elementary form is a very reactive element and react strongly with hot metal surfaces. Due to the strong chemisorption interaction, in the target and ion source unit, the atoms undergo significant retention on their way from the target to the ion source. Due to this the short lived isotopes decays and are lost leading to low ion yields. A first approach to tackle these limitations consists of incorporating the carbon atoms into less reactive molecules and to use materials for the target housing and the transfer line ...

  16. Carbon nanotubes doped with trivalent elements by using back - scattering Raman spectroscopy

    Directory of Open Access Journals (Sweden)

    S. A. Babanejad

    2008-12-01

    Full Text Available  In this paper by using DC arc discharge method and acetylene gas, as the carbon source, and nitrogen, as the carrier gas, canrbon nanotubes, CNTs, doped with trivalent element boron, B, have been produced. The deposited CNTs on the cathod electrod, which have structural doped properties to boron element, have been collected and after purification have been investigated by back-scattering Raman spectroscopy. The results reveal that the high frequency G mode component in CNTs doped with electron acceptor element, B, shift to higher wavenumbers. The low frequency G mode component which can appear at approximately 1540–1570 cm-1 wavenumber region, called BWF mode, is a sign of metallic CNT. In the synthesized doped CNTs due to the presence of boron dopant, D mode has sharp peaks and has relatively high intensity in the Raman spectra .

  17. Thermodynamic Properties of Aqueous Carbonate Species and Solid Carbonate Phases of Selected Trace Elements pertinent to Drinking Water Standards of the U.S. Environmental Protection Agency

    Energy Technology Data Exchange (ETDEWEB)

    Apps, John A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wilkin, Richard T. [US Environmental Protection Agency (EPA), Cincinnati, OH (United States)

    2015-09-30

    This report contains a series of tables summarizing the thermodynamic properties of aqueous carbonate complexes and solid carbonate phases of the following elements: arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), nickel (Ni) thallium (Tl), uranium (U) and zinc (Zn). Most of these elements are potentially hazardous as defined by extant primary drinking water standards of the United States Environmental Protection Agency (EPA). The remainder are not considered hazardous, but are either listed by EPA under secondary standards, or because they can adversely affect drinking water quality. Additional tables are included giving the thermodynamic properties for carbonates of the alkali metal and alkali earth elements, sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and strontium (Sr), because of their value in developing correlative models to estimate the thermodynamic properties of carbonate minerals for which no such data currently exist. The purpose in creating the tables in this report is to provide future investigators with a convenient source for selecting and tracing the sources of thermodynamic data of the above listed elements for use in modeling their geochemical behavior in “underground sources of drinking water” (USDW). The incentive for doing so lies with a heightened concern over the potential consequences of the proposed capture and storage of carbon dioxide (CO2) generated by fossil fuel fired power plants in deep subsurface reservoirs. If CO2 were to leak from such reservoirs, it could migrate upward and contaminate USDWs with undesirable, but undetermined, consequences to water quality. The EPA, Office of Research and Development, through an Interagency Agreement with the U.S. Department of Energy at the Lawrence Berkeley National Laboratory, funded the preparation of this report.

  18. Volatile elements - water, carbon, nitrogen, noble gases - on Earth

    Science.gov (United States)

    Marty, B.

    2017-12-01

    Understanding the origin and evolution of life-bearing volatile elements (water, carbon, nitrogen) on Earth is a fruitful and debated area of research. In his pioneering work, W.W. Rubey inferred that the terrestrial atmosphere and the oceans formed from degassing of the mantle through geological periods of time. Early works on noble gas isotopes were consistent with this view and proposed a catastrophic event of mantle degassing early in Earth's history. We now have evidence, mainly from noble gas isotopes, that several cosmochemical sources contributed water and other volatiles at different stages of Earth's accretion. Potential contributors include the protosolar nebula gas that equilibrated with magma oceans, inner solar system bodies now represented by chondrites, and comets. Stable isotope ratios suggest volatiles where primarily sourced by planetary bodies from the inner solar system. However, recent measurements by the European Space Agency Rosetta probe on the coma of Comet 67P/Churyumov-Gerasimenko permit to set quantitative constraints on the cometary contribution to the surface of our planet. The surface and mantle reservoirs volatile elements exchanged volatile elements through time, with rates that are still uncertain. Some mantle regions remained isolated from whole mantle convection within the first tens to hundreds million years after start of solar system formation. These regions, now sampled by some mantle plumes (e.g., Iceland, Eifel) preserved their volatile load, as indicated by extinct and extant radioactivity systems. The abundance of volatile elements in the mantle is still not well known. Different approaches, such as high pressure experimental petrology, noble gas geochemistry, modelling, resulted in somewhat contrasted estimates, varying over one order of magnitude for water. Comparative planetology, that is, the study of volatiles on the Moon, Venus, Mars, Vesta, will shed light on the sources and strengths of these elements in the

  19. Carbon allocation and element composition in four Chlamydomonas mutants defective in genes related to the CO2 concentrating mechanism

    Czech Academy of Sciences Publication Activity Database

    Memmola, F.; Mukherjee, B.; Moroney, James V.; Giordano, Mario

    2014-01-01

    Roč. 121, 2-3 (2014), s. 201-211 ISSN 0166-8595 Institutional support: RVO:61388971 Keywords : Chlamydomonas mutants * carbon * carbon dioxide * elemental stoichiometry Subject RIV: EE - Microbiology, Virology Impact factor: 3.502, year: 2014

  20. 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

  1. 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.)

  2. 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

  3. Genome-wide identification of regulatory elements and reconstruction of gene regulatory networks of the green alga Chlamydomonas reinhardtii under carbon deprivation.

    Directory of Open Access Journals (Sweden)

    Flavia Vischi Winck

    Full Text Available The unicellular green alga Chlamydomonas reinhardtii is a long-established model organism for studies on photosynthesis and carbon metabolism-related physiology. Under conditions of air-level carbon dioxide concentration [CO2], a carbon concentrating mechanism (CCM is induced to facilitate cellular carbon uptake. CCM increases the availability of carbon dioxide at the site of cellular carbon fixation. To improve our understanding of the transcriptional control of the CCM, we employed FAIRE-seq (formaldehyde-assisted Isolation of Regulatory Elements, followed by deep sequencing to determine nucleosome-depleted chromatin regions of algal cells subjected to carbon deprivation. Our FAIRE data recapitulated the positions of known regulatory elements in the promoter of the periplasmic carbonic anhydrase (Cah1 gene, which is upregulated during CCM induction, and revealed new candidate regulatory elements at a genome-wide scale. In addition, time series expression patterns of 130 transcription factor (TF and transcription regulator (TR genes were obtained for cells cultured under photoautotrophic condition and subjected to a shift from high to low [CO2]. Groups of co-expressed genes were identified and a putative directed gene-regulatory network underlying the CCM was reconstructed from the gene expression data using the recently developed IOTA (inner composition alignment method. Among the candidate regulatory genes, two members of the MYB-related TF family, Lcr1 (Low-CO 2 response regulator 1 and Lcr2 (Low-CO2 response regulator 2, may play an important role in down-regulating the expression of a particular set of TF and TR genes in response to low [CO2]. The results obtained provide new insights into the transcriptional control of the CCM and revealed more than 60 new candidate regulatory genes. Deep sequencing of nucleosome-depleted genomic regions indicated the presence of new, previously unknown regulatory elements in the C. reinhardtii genome

  4. Preparation of thin nuclear targets

    International Nuclear Information System (INIS)

    Muggleton, A.H.F.

    1979-03-01

    Thin film backings, sources and targets are needed for many applications in low energy nuclear physics and nuclear chemistry experiments. A survey of techniques used in the preparation of nuclear targets is first briefly discussed. These are classified as chemical, mechanical and physical preparations. Vacuum evaporation, being the most generally used technique, is discussed in detail. It is highly desirable to monitor the film thickness and control the deposition rate during evaporation and to measure the final target thickness after deposition has concluded. The relative merits of various thickness measuring techniques are described. Stages in the fabrication and mounting of self-supporting foils are described in detail, with emphasis given to the preparation of thin self-supporting carbon foils used as target backings and stripper foils. Various target backings, and the merits of the more generally used release agents are described in detail. The preparations of more difficult elemental targets are discussed, and a comprehensive list of the common targets is presented

  5. Infrared thermography inspection methods applied to the target elements of W7-X divertor

    Energy Technology Data Exchange (ETDEWEB)

    Missirlian, M. [Association Euratom-CEA, CEA/DSM/DRFC, CEA/Cadarache, F-13108 Saint Paul Lez Durance (France)], E-mail: marc.missirlian@cea.fr; Traxler, H. [PLANSEE SE, Technology Center, A-6600 Reutte (Austria); Boscary, J. [Max-Planck-Institut fuer Plasmaphysik, Euratom Association, Boltzmannstr. 2, D-85748 Garching (Germany); Durocher, A.; Escourbiac, F.; Schlosser, J. [Association Euratom-CEA, CEA/DSM/DRFC, CEA/Cadarache, F-13108 Saint Paul Lez Durance (France); Schedler, B.; Schuler, P. [PLANSEE SE, Technology Center, A-6600 Reutte (Austria)

    2007-10-15

    The non-destructive examination (NDE) method is one of the key issues in developing highly loaded plasma-facing components (PFCs) for a next generation fusion devices such as W7-X and ITER. The most critical step is certainly the fabrication and the examination of the bond between the armour and the heat sink. Two inspection systems based on the infrared thermography methods, namely, the transient thermography (SATIR-CEA) and the pulsed thermography (ARGUS-PLANSEE), are being developed and have been applied to the pre-series of target elements of the W7-X divertor. Results obtained from qualification experiences performed on target elements with artificial calibrated defects allowed to demonstrate the capability of the two techniques and raised the efficiency of inspection to a level which is appropriate for industrial application.

  6. Infrared thermography inspection methods applied to the target elements of W7-X divertor

    International Nuclear Information System (INIS)

    Missirlian, M.; Traxler, H.; Boscary, J.; Durocher, A.; Escourbiac, F.; Schlosser, J.; Schedler, B.; Schuler, P.

    2007-01-01

    The non-destructive examination (NDE) method is one of the key issues in developing highly loaded plasma-facing components (PFCs) for a next generation fusion devices such as W7-X and ITER. The most critical step is certainly the fabrication and the examination of the bond between the armour and the heat sink. Two inspection systems based on the infrared thermography methods, namely, the transient thermography (SATIR-CEA) and the pulsed thermography (ARGUS-PLANSEE), are being developed and have been applied to the pre-series of target elements of the W7-X divertor. Results obtained from qualification experiences performed on target elements with artificial calibrated defects allowed to demonstrate the capability of the two techniques and raised the efficiency of inspection to a level which is appropriate for industrial application

  7. The production of sulfur targets for gamma-ray spectroscopy

    CERN Document Server

    Greene, J P

    2002-01-01

    The production of thin sulfur targets for nuclear physics, either in elemental or in compound form, is problematic, due to low melting points, high vapor pressures and high dissociation rates. Many sulfur compounds have been tried in the past without great success. In this paper, we report the use of spray coating molybdenum disulfide onto a thin carbon backing. The targets were of thickness 750 mu g/cm sup 2 (approx 300 mu g/cm sup 2 of sulfur) on 15 mu g/cm sup 2 carbon backings, and withstood 4 pnA (approx 10 mW/cm sup 2) of deposited beam power for several days without apparent loss of sulfur content.

  8. Organic Carbon and Trace Element Cycling in a River-Dominated Tidal Coastal Wetland System (Tampa Bay, FL, USA)

    Science.gov (United States)

    Moyer, R. P.; Smoak, J. M.; Engelhart, S. E.; Powell, C. E.; Chappel, A. R.; Gerlach, M. J.; Kemp, A.; Breithaupt, J. L.

    2016-02-01

    Tampa Bay is the largest open water, river-fed estuary in Florida (USA), and is characterized by the presence of both mangrove and salt marsh ecosystems. Both coastal wetland systems, and small rivers such as the ones draining into Tampa Bay have historically been underestimated in terms of their role in the global carbon and elemental cycles. Climate change and sea-level rise (SLR) are major threats in Tampa Bay and stand to disrupt hydrologic cycles, compromising sediment accumulation and the rate of organic carbon (OC) burial. This study evaluates organic carbon content, sediment accumulation, and carbon burial rates in salt marsh and mangrove ecosystems, along with measurements of fluxes of dissolved OC (DOC) and trace elements in the water column of the Little Manatee River (LMR) in Tampa Bay. The characterization of OC and trace elements in tidal rivers and estuaries is critical for quantitatively constraining these systems in local-to-regional scale biogeochemical budgets, and provide insight into biogeochemical processes occurring with the estuary and adjacent tidal wetlands. Material fluxes of DOC and trace elements were tied to discharge irrespective of season, and the estuarine habitats removed 15-65% of DOC prior to export to Tampa Bay and the Gulf of Mexico. Thus, material is available for cycling and burial within marsh and mangrove peats, however, LMR mangrove peats have higher OC content and burial rates than adjacent salt marsh peats. Sedimentary accretion rates in LMR marshes are not currently keeping pace with SLR, thus furthering the rapid marsh-to-mangrove conversions that have been seen in Tampa Bay over the past half-century. Additionally, wetlands in Tampa Bay tend to have a lower rate of carbon burial than other Florida tidal wetlands, demonstrating their high sensitivity to climate change and SLR.

  9. Elemental mercury vapor capture by powdered activated carbon in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Fabrizio Scala; Riccardo Chirone; Amedeo Lancia [Istituto di Ricerche sulla Combustione - CNR, Napoli (Italy)

    2011-06-15

    A bubbling fluidized bed of inert material was used to increase the activated carbon residence time in the reaction zone and to improve its performance for mercury vapor capture. Elemental mercury capture experiments were conducted at 100{sup o}C in a purposely designed 65 mm ID lab-scale pyrex reactor, that could be operated both in the fluidized bed and in the entrained bed configurations. Commercial powdered activated carbon was pneumatically injected in the reactor and mercury concentration at the outlet was monitored continuously. Experiments were carried out at different inert particle sizes, bed masses, fluidization velocities and carbon feed rates. Experimental results showed that the presence of a bubbling fluidized bed led to an increase of the mercury capture efficiency and, in turn, of the activated carbon utilization. This was explained by the enhanced activated carbon loading and gas-solid contact time that establishes in the reaction zone, because of the large surface area available for activated carbon adhesion/deposition in the fluidized bed. Transient mercury concentration profiles at the bed outlet during the runs were used to discriminate between the controlling phenomena in the process. Experimental data have been analyzed in the light of a phenomenological framework that takes into account the presence of both free and adhered carbon in the reactor as well as mercury saturation of the adsorbent. 14 refs., 7 figs.

  10. Design specification for the European Spallation Source neutron generating target element

    International Nuclear Information System (INIS)

    Aguilar, A.; Sordo, F.; Mora, T.; Mena, L.; Mancisidor, M.; Aguilar, J.; Bakedano, G.; Herranz, I.; Luna, P.; Magan, M.; Vivanco, R.; Jimenez-Villacorta, F.; Sjogreen, K.; Oden, U.; Perlado, J.M.

    2017-01-01

    The paper addresses some of the most relevant issues concerning the thermal hydraulics and radiation damage of the neutron generation target to be built at the European Spallation Source as recently approved after a critical design review. The target unit consists of a set of Tungsten blocks placed inside a wheel of 2.5 m diameter which rotates at some 0.5 Hz in order to distribute the heat generated from incoming protons which reach the target in the radial direction. The spallation material elements are composed of an array of Tungsten pieces which rest on a rotating steel support (the cassette) and are distributed in a cross-flow configuration. The thermal, mechanical and radiation effects resulting from the impact of a 2 GeV proton pulse are analysed in detail as well as an evaluation of the inventory of spallation products. The current design is found to conform to specifications and found to be robust enough to deal with several accident scenarios.

  11. Design specification for the European Spallation Source neutron generating target element

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, A. [Consorcio ESS-BILBAO. Parque Tecnológico Bizkaia. Poligono Ugaldeguren III, Pol. A, 7B, 48170 Zamudio (Spain); Sordo, F., E-mail: fernando.sordo@essbilbao.org [Consorcio ESS-BILBAO. Parque Tecnológico Bizkaia. Poligono Ugaldeguren III, Pol. A, 7B, 48170 Zamudio (Spain); Instituto de Fusión Nuclear, José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Mora, T. [Consorcio ESS-BILBAO. Parque Tecnológico Bizkaia. Poligono Ugaldeguren III, Pol. A, 7B, 48170 Zamudio (Spain); Mena, L. [Consorcio ESS-BILBAO. Parque Tecnológico Bizkaia. Poligono Ugaldeguren III, Pol. A, 7B, 48170 Zamudio (Spain); Instituto de Fusión Nuclear, José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Mancisidor, M.; Aguilar, J.; Bakedano, G.; Herranz, I.; Luna, P. [Consorcio ESS-BILBAO. Parque Tecnológico Bizkaia. Poligono Ugaldeguren III, Pol. A, 7B, 48170 Zamudio (Spain); Magan, M.; Vivanco, R. [Consorcio ESS-BILBAO. Parque Tecnológico Bizkaia. Poligono Ugaldeguren III, Pol. A, 7B, 48170 Zamudio (Spain); Instituto de Fusión Nuclear, José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Jimenez-Villacorta, F. [Consorcio ESS-BILBAO. Parque Tecnológico Bizkaia. Poligono Ugaldeguren III, Pol. A, 7B, 48170 Zamudio (Spain); Sjogreen, K.; Oden, U. [European Spallation Source ERIC, P.O Box 176, SE-221 00 Lund (Sweden); Perlado, J.M. [Instituto de Fusión Nuclear, José Gutiérrez Abascal, 2, 28006 Madrid (Spain); and others

    2017-06-01

    The paper addresses some of the most relevant issues concerning the thermal hydraulics and radiation damage of the neutron generation target to be built at the European Spallation Source as recently approved after a critical design review. The target unit consists of a set of Tungsten blocks placed inside a wheel of 2.5 m diameter which rotates at some 0.5 Hz in order to distribute the heat generated from incoming protons which reach the target in the radial direction. The spallation material elements are composed of an array of Tungsten pieces which rest on a rotating steel support (the cassette) and are distributed in a cross-flow configuration. The thermal, mechanical and radiation effects resulting from the impact of a 2 GeV proton pulse are analysed in detail as well as an evaluation of the inventory of spallation products. The current design is found to conform to specifications and found to be robust enough to deal with several accident scenarios.

  12. 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.

  13. Reference Materials for Trace Element Microanalysis of Carbonates by SIMS and other Mass Spectrometric Techniques

    Science.gov (United States)

    Layne, G. D.

    2009-12-01

    Today, many areas of geochemical research utilize microanalytical determinations of trace elements in carbonate minerals. In particular, there has been an explosion in the application of Secondary Ion Mass Spectrometry (SIMS) to studies of marine biomineralization. SIMS provides highly precise determinations of Mg and Sr at the concentration levels normally encountered in corals, mollusks or fish otoliths. It is also a highly effective means for determining a wide range of other trace elements at ppm levels (e.g., Na, Fe, Mn, Ba, REE, Pb, Th, and U) in a variety of naturally occurring calcite and aragonite matrices - and so is potentially valuable in studies of diagenesis, hydrothermal fluids and carbonatitic magmas. For SIMS, modest time per spot (often sputtered ion yields of most elements with the major element composition of the sample matrix, accuracy of SIMS depends intimately on matrix-matched solid reference materials. Despite its rapidly increasing use for trace element analyses of carbonates, there remains a dearth of certified reference materials suitable for calibrating SIMS. The pressed powders used by some analysts to calibrate LA-ICP-MS do not perform well for SIMS - they are not perfectly dense or homogeneous to the desired level at the micron scale of sampling. Further, they often prove incompatible with the sample high vacuum compatibility requirement for stable SIMS analysis (10-8 to 10-9 torr). Some naturally occurring calcite has apparent utility as a reference material. For example, equigranular calcite from some zones of carbonatite intrusions (sovites) and recrystallized calcites from highly metamorphosed metallic ore deposits. Most calcite marbles, though possibly appropriate as Sr standards, show substantial inhomogeneity in Mg, Mn and Ba. Some hydrothermal “Iceland Spar” calcite may prove useful as a reference for extremely low concentrations of Mg, Sr and Ba. The best carbonatitic calcites currently in use appear homogeneous to

  14. Transplutonium elements production program: extraction chromatographic process for plutonium irradiated targets

    International Nuclear Information System (INIS)

    Bourges, J.; Madic, C.; Koehly, G.

    1980-01-01

    The treatment of irradiated plutonium targets by extraction chromatography allowed the purification of the isotopes 243 Am and 244 Cm on the scale of few tens of grams. This process proved to be extremely simple and flexible, and yielded results which are reproducible in time. The chief advantage of the TBP process over the HDEHP process in high and medium activity conditions lies in the rapid absorption/desorption kinetics of the elements to be purified and in the separation of americium from curium, which largely offsets its lower selectivity for lanthanide elements. it is certainly possible to improve the performance of this process by: a) optimization of the characteristics of the stationary phase, b) improvement in the filling technique and in hydraulic operation of the columns, c) on-line analysis of americium (the key element in actinide/lanthanide separation) in the eluate. The application of extraction chromatography with HD(DiBM)P to the purification of 243 Am of the end of treatment makes the process more consistent, eliminates the delicate stages implemented in hot cell, and considerably improves final product quality

  15. 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.

  16. 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.

  17. Carbon footprint assessment of recycling technologies for rare earth elements: A case study of recycling yttrium and europium from phosphor.

    Science.gov (United States)

    Hu, Allen H; Kuo, Chien-Hung; Huang, Lance H; Su, Chao-Chin

    2017-02-01

    Rare earth elements are key raw materials in high-technology industries. Mining activities and manufacturing processes of such industries have caused considerable environmental impacts, such as soil erosion, vegetation destruction, and various forms of pollution. Sustaining the long-term supply of rare earth elements is difficult because of the global shortage of rare earth resources. The diminishing supply of rare earth elements has attracted considerable concern because many industrialized countries regarded such elements as important strategic resources for economic growth. This study aims to explore the carbon footprints of yttrium and europium recovery techniques from phosphor. Two extraction recovery methods, namely, acid extraction and solvent extraction, were selected for the analysis and comparison of carbon footprints. The two following functional units were used: (1) the same phosphor amounts for specific Y and Eu recovery concentrations, and (2) the same phosphor amounts for extraction. For acid extraction method, two acidic solutions (H 2 SO 4 and HCl) were used at two different temperatures (60 and 90°C). For solvent extraction method, acid leaching was performed followed by ionic liquid extraction. Carbon footprints from acid and solvent extraction methods were estimated to be 10.1 and 10.6kgCO 2 eq, respectively. Comparison of the carbon emissions of the two extraction methods shows that the solvent extraction method has significantly higher extraction efficiency, even though acid extraction method has a lower carbon footprint. These results may be used to develop strategies for life cycle management of rare earth resources to realize sustainable usage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. High heat flux tests of the WENDELSTEIN 7-X pre-series target elements - experimental evaluation of the thermo-mechanical behaviour

    International Nuclear Information System (INIS)

    Greuner, H.; Boeswirth, B.; Boscary, J.; Plankensteiner, A.; Schedler, B.

    2006-01-01

    The HHF testing of WENDELSTEIN 7-X pre-series target elements is an indispensable step in the qualification of the manufacturing process. The finally 890 divertor target elements are made of an actively water-cooled CuCrZr heat sink covered with flat tiles of CFC NB31 as plasma facing material. A set of 20 full scale pre-series elements was manufactured by PLANSEE to validate the materials and manufacturing technologies prior to the start of the series production. Due to the large mismatch in the coefficients of thermal expansion for CFC and CuCrZr - resulting in high residual stresses as well as high operation-induced stresses - the bonding zone between CFC and CuCrZr was detected to be the most critical issue for the operational behaviour of the target elements. To achieve a sufficiently high manufacturing quality together with a high lifetime during operation thermal testing of full scale mockups was performed in combination with extensive FEM analyses. In both cases heat loads were applied similar to the expected heat loads in W7-X. All pre-series elements were tested in the ion beam test facility GLADIS. The elements were tested with 100 cycles of 10 MW/m 2 and several elements with even higher cycle numbers and heat loads up to 24 MW/m 2 . The instrumentation of the targets (thermocouples, strain gages) and the infrared camera observation of the heat loaded surface allow an experimental evaluation of the thermo-mechanical behaviour of the tested elements. The main result is a good agreement between experimental data and numerically computed predictions. Hot spots were, however, observed at the edges of several tiles during the HHF tests indicating local bonding problems. Therefore, a programme of fully 3D nonlinear thermal-mechanical FEM calculations was started to evaluate the thermo-mechanical behavior of the target elements with special focus on the optimization of the stress situation in the bonding zone between the CFC and the CuCrZr heat sink. This

  19. Modular assembly of transposable element arrays by microsatellite targeting in the guayule and rice genomes.

    Science.gov (United States)

    Valdes Franco, José A; Wang, Yi; Huo, Naxin; Ponciano, Grisel; Colvin, Howard A; McMahan, Colleen M; Gu, Yong Q; Belknap, William R

    2018-04-19

    Guayule (Parthenium argentatum A. Gray) is a rubber-producing desert shrub native to Mexico and the United States. Guayule represents an alternative to Hevea brasiliensis as a source for commercial natural rubber. The efficient application of modern molecular/genetic tools to guayule improvement requires characterization of its genome. The 1.6 Gb guayule genome was sequenced, assembled and annotated. The final 1.5 Gb assembly, while fragmented (N 50  = 22 kb), maps > 95% of the shotgun reads and is essentially complete. Approximately 40,000 transcribed, protein encoding genes were annotated on the assembly. Further characterization of this genome revealed 15 families of small, microsatellite-associated, transposable elements (TEs) with unexpected chromosomal distribution profiles. These SaTar (Satellite Targeted) elements, which are non-autonomous Mu-like elements (MULEs), were frequently observed in multimeric linear arrays of unrelated individual elements within which no individual element is interrupted by another. This uniformly non-nested TE multimer architecture has not been previously described in either eukaryotic or prokaryotic genomes. Five families of similarly distributed non-autonomous MULEs (microsatellite associated, modularly assembled) were characterized in the rice genome. Families of TEs with similar structures and distribution profiles were identified in sorghum and citrus. The sequencing and assembly of the guayule genome provides a foundation for application of current crop improvement technologies to this plant. In addition, characterization of this genome revealed SaTar elements with distribution profiles unique among TEs. Satar targeting appears based on an alternative MULE recombination mechanism with the potential to impact gene evolution.

  20. Antisense oligonucleotides targeting translation inhibitory elements in 5' UTRs can selectively increase protein levels.

    Science.gov (United States)

    Liang, Xue-Hai; Sun, Hong; Shen, Wen; Wang, Shiyu; Yao, Joyee; Migawa, Michael T; Bui, Huynh-Hoa; Damle, Sagar S; Riney, Stan; Graham, Mark J; Crooke, Rosanne M; Crooke, Stanley T

    2017-09-19

    A variety of diseases are caused by deficiencies in amounts or activity of key proteins. An approach that increases the amount of a specific protein might be of therapeutic benefit. We reasoned that translation could be specifically enhanced using trans-acting agents that counter the function of negative regulatory elements present in the 5' UTRs of some mRNAs. We recently showed that translation can be enhanced by antisense oligonucleotides (ASOs) that target upstream open reading frames. Here we report the amount of a protein can also be selectively increased using ASOs designed to hybridize to other translation inhibitory elements in 5' UTRs. Levels of human RNASEH1, LDLR, and ACP1 and of mouse ACP1 and ARF1 were increased up to 2.7-fold in different cell types and species upon treatment with chemically modified ASOs targeting 5' UTR inhibitory regions in the mRNAs encoding these proteins. The activities of ASOs in enhancing translation were sequence and position dependent and required helicase activity. The ASOs appear to improve the recruitment of translation initiation factors to the target mRNA. Importantly, ASOs targeting ACP1 mRNA significantly increased the level of ACP1 protein in mice, suggesting that this approach has therapeutic and research potentials. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  1. Integral excitation functions for proton and alpha induced reactions on target elements 22 <= Z <= 28

    International Nuclear Information System (INIS)

    Brinkmann, G.

    1979-01-01

    In the framework of a systematic study which is also important for certain cosmological questions a series of integral excitation functions of p- and α-induced nuclear reactions on target elements 22 [de

  2. 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

  3. 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.

  4. 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 ...

  5. Stages of weathering mantle formation from carbonate rocks in the light of rare earth elements (REE) and Sr-Nd-Pb isotopes

    Science.gov (United States)

    Hissler, Christophe; Stille, Peter

    2015-04-01

    Weathering mantles are widespread and include lateritic, sandy and kaolinite-rich saprolites and residuals of partially dissolved rocks. These old regolith systems have a complex history of formation and may present a polycyclic evolution due to successive geological and pedogenetic processes that affected the profile. Until now, only few studies highlighted the unusual high content of associated trace elements in weathering mantles originating from carbonate rocks, which have been poorly studied, compared to those developing on magmatic bedrocks. For instance, these enrichments can be up to five times the content of the underlying carbonate rocks. However, these studies also showed that the carbonate bedrock content only partially explains the soil enrichment for all the considered major and trace elements. Up to now, neither soil, nor saprolite formation has to our knowledge been geochemically elucidated. Therefore, the aim of this study was to examine more closely the soil forming dynamics and the relationship of the chemical soil composition to potential sources. REE distribution patterns and Sr-Nd-Pb isotope ratios have been used because they are particularly well suited to identify trace element migration, to recognize origin and mixing processes and, in addition, to decipher possible anthropogenic and/or "natural" atmosphere-derived contributions to the soil. Moreover, leaching experiments have been applied to identify mobile phases in the soil system and to yield information on the stability of trace elements and especially on their behaviour in these Fe-enriched carbonate systems. All these geochemical informations indicate that the cambisol developing on such a typical weathering mantle ("terra fusca") has been formed through weathering of a condensed Bajocian limestone-marl facies. This facies shows compared to average world carbonates important trace element enrichments. Their trace element distribution patterns are similar to those of the soil

  6. Ambient concentrations and insights on organic and elemental carbon dynamics in São Paulo, Brazil

    Science.gov (United States)

    Monteiro dos Santos, Djacinto A.; Brito, Joel F.; Godoy, José Marcus; Artaxo, Paulo

    2016-11-01

    The São Paulo Metropolitan Area (SPMA) is a megacity with about 20 million people and about 8 million vehicles, most of which are fueled with a significant fraction of ethanol - making it a unique case worldwide. This study presents organic and elemental carbon measurements using thermal-optical analysis from quartz filters collected in four sampling sites within the SPMA. Overall Organic Carbon (OC) concentration was comparable at all sites, where Street Canyon had the highest concentration (3.37 μg m-3) and Park site the lowest (2.65 μg m-3). Elemental Carbon (EC), emitted as result of incomplete combustion, has been significantly higher at the Street Canyon site (6.11 μg m-3) in contrast to all other three sites, ranging from 2.25 μg m-3 (Downtown) to 1.50 μg m-3 (Park). For all sampling sites, the average OC:EC ratio are found on the lower bound (pollution dynamics in a megacity impacted by a unique vehicular fleet. It also shows the need of implementation of EURO VI technology and to improve mass transport systems such a metro and more bus corridors to allow better transport for 19 million people in the SPMA.

  7. The applicaton of neutron radioscopy to lithium-aluminum alloy target elements

    International Nuclear Information System (INIS)

    Antal, J.J.; Marotta, A.S.; Salaymeh, S.R.; Varallo, T.P.

    1989-01-01

    The authors show that neutron radioscopy is very useful in locating the position of a Li-A1 alloy core enriched in Lithium-6 in tubular aluminum target elements. The alloy core is displaced during a forming process and its location must be redetermined before processing can be completed. A low-flux mobile neutron radioscopy system was employed in these studies as a model system for possible on-line, in-plant use. A series of core end sections of target tubes containing from 0.1 to 4.6 grams of Lithium-6 per foot of length were examined radioscopically with thermal neutrons. The system was able to determine the extent of lithium alloy core from the highest concentrations down to about 0.2 grams of Lithium-6 per ft within one minute of data collection time

  8. Synthesis of Antimony Doped Amorphous Carbon Films

    Science.gov (United States)

    Okuyama, H.; Takashima, M.; Akasaka, H.; Ohtake, N.

    2013-06-01

    We report the effects of antimony (Sb) doping on the electrical and optical properties of amorphous carbon (a-C:H) films grown on silicon and copper substrates by magnetron sputtering deposition. For film deposition, the mixture targets fabricated from carbon and antimony powders was used. The atomic concentration of carbon, hydrogen, and antimony, in the film deposited from the 1.0 mol% Sb containing target were 81, 17, 2 at.%, respectively. These elements were homogeneously distributed in the film. On the structural effect, the average continuous sp2 carbon bonding networks decreased with Sb concentration increasing, and defects in the films were increased with the Sb incorporation because atomic radius of Sb atoms is twice larger size than that of carbon. The optical gap and the electrical resistivity were carried out before and after the Sb doping. The results show that optical gap dropped from 3.15 to 3.04 eV corresponding to non-doping to Sb-doping conditions, respectively. The electrical resistivity reduced from 10.5 to 1.0 MΩm by the Sb doping. These results suggest the doping level was newly formed in the forbidden band.

  9. Synthesis of Antimony Doped Amorphous Carbon Films

    International Nuclear Information System (INIS)

    Okuyama, H; Takashima, M; Akasaka, H; Ohtake, N

    2013-01-01

    We report the effects of antimony (Sb) doping on the electrical and optical properties of amorphous carbon (a-C:H) films grown on silicon and copper substrates by magnetron sputtering deposition. For film deposition, the mixture targets fabricated from carbon and antimony powders was used. The atomic concentration of carbon, hydrogen, and antimony, in the film deposited from the 1.0 mol% Sb containing target were 81, 17, 2 at.%, respectively. These elements were homogeneously distributed in the film. On the structural effect, the average continuous sp 2 carbon bonding networks decreased with Sb concentration increasing, and defects in the films were increased with the Sb incorporation because atomic radius of Sb atoms is twice larger size than that of carbon. The optical gap and the electrical resistivity were carried out before and after the Sb doping. The results show that optical gap dropped from 3.15 to 3.04 eV corresponding to non-doping to Sb-doping conditions, respectively. The electrical resistivity reduced from 10.5 to 1.0 MΩm by the Sb doping. These results suggest the doping level was newly formed in the forbidden band.

  10. Single electron detachment of carbon group and oxygen group elements incident on helium

    International Nuclear Information System (INIS)

    Huang Yongyi; Li Guangwu; Gao Yinghui; Yang Enbo; Gao Mei; Lu Fuquan; Zhang Xuemei

    2006-01-01

    The absolute single electron detachment (SED) cross sections of carbon group elements C - , Si - , Ge - in the energy range of 0.05-0.29 a.u. (5 keV-30 keV) and oxygen group elements O - and S - 0.08-0.27 a.u. (5 keV-30 keV), incident on helium are measured with growth rate method. In our energy region, the SED cross sections of C - , Si - , S - and Ge - increase with the projectiles velocity, at the same time, O - cross sections reach a conspicuous maximum at 0.18 a.u. Some abnormal behavior occurs in measurement of SED cross sections for the oxygen group collision with helium. Our results have been compared with a previous work

  11. Organic and Elemental Carbon Aerosol Particulates at the Southern Great Plains Site Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Robert

    2016-04-01

    The purpose of this study was to measure the organic carbon (OC) and elemental carbon (EC) fractions of PM2.5 particulate matter at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) sampling site for a 6-month period during the summer of 2013. The site is in a rural location remote from any populated areas, so it would be expected to reflect carbon concentration over long-distance transport patterns. During the same period in 2012, a number of prairie fires in Oklahoma and Texas had produced large plumes of smoke particles, but OC and EC particles had not been quantified. In addition, during the summer months, other wild fires, such as forest fires in the Rocky Mountain states and other areas, can produce carbon aerosols that are transported over long distances. Both of these source types would be expected to contain mixtures of both OC and EC.

  12. Quantitative assessment of elemental carbon in the lungs of never smokers, cigarette smokers and coal miners

    Science.gov (United States)

    Inhalation exposure to particulates such as cigarette smoke and coal dust is known to contribute to the development of chronic lung disease. The purpose of this study was to estimate the amount of elemental carbon (EC) deposits from autopsied lung samples from cigarette smokers, ...

  13. 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.

  14. Microparticles and human health: particulate materials, trace metals elements and black carbon in aerosols collected at Andravoahangy-Antananarivo, Madagascar

    International Nuclear Information System (INIS)

    Rasoazanany, E. O.; Andriamahenina, N. N.; Harinoely, M.; Ravoson, H. N.; Randriamanivo, L. V.; Raoelina Andriambololona; Ramaherison, H.

    2013-01-01

    The present work is to determine the concentrations of microparticles having diameter inferior to 10 μm (PM 10 ), the metal trace elements and the black carbon in the aerosols sampled in Andravoahangy-Antananarivo, Madagascar in 2008. The air sampler GENT is used to collect aerosol samples. The total reflection X-ray fluorescence spectrometer is used for qualitative and quantitative analysis of simultaneous way all metallic trace elements contained in the aerosols. The M43D reflectometer permits to measure the reflectances in order to determine the black carbon concentrations. The results show that the average concentrations of the particulate matters PM 2,5-10 are higher than those of PM 2,5 . The average concentrations of PM 10 in the aerosols are exceeding the World Health Organisation (WHO) and European Union guidelines, set at 50 μg.m -3 and those of PM 2,5 are higher than the 2005 WHO (25 μg.m-3) and the United States Environment Protection Agency (35 μg.m -3 ) guidelines. Consequently, air quality in Andravoahangy does not respect these daily guidelines. The identified metallic trace elements in the aerosols are Ti, Cr, Mn, Fe, Ni, Cu, Zn and Pb. The average concentrations of these elements are also higher in the coarse particles than in the fine particles. The concentrations of black carbon are higher in the fine particles. The maximum value is 9.12 μg.m -3 . [fr

  15. Mobilisation of toxic trace elements under various beach nourishments.

    Science.gov (United States)

    Pit, Iris R; Dekker, Stefan C; Kanters, Tobias J; Wassen, Martin J; Griffioen, Jasper

    2017-12-01

    To enhance protection and maintain wide beaches for recreation, beaches are replenished with sand: so-called beach nourishments. We compared four sites: two traditional beach nourishments, a mega beach nourishment and a reference without beach nourishment. Two sites contain calcareous-rich sand, whereas the other two sites have calcareous-poor sand. We aimed to understand hydrogeochemical processes to indicate factors critical for the mobility of trace elements at nourishments. We therefore analysed the chemical characteristics of sediment and pore water to ascertain the main drivers that mobilise toxic trace elements. With Dutch Quality Standards for soil and groundwater, the characteristics of sediment and pore water were compared to Target Values (the values at which there is a sustainable soil quality) and Intervention Values (the threshold above which the soil's functions are at risk). The pore water characteristics revealed that Target Values were regularly exceeded, especially for the nourishment sites and mainly for Mo (78%), Ni (24%), Cr (55%), and As (21%); Intervention Values for shallow groundwater were occasionally exceeded for As (2%), Cr (2%) and Zn (2%). The sediment characteristics did not exceed the Target Values and showed that trace elements were mainly present in the fine fraction of <150 μm. The oxidation of sulphide minerals such as pyrite resulted into the elevated concentration for all nourishment sites, especially when an unsaturated zone was present and influence of rainwater was apparent. To prevent trace metal mobility at a mega beach nourishment it is important to retain seawater influences and limit oxidation processes. In this respect, a shoreface nourishment is recommended rather than a mega beach nourishment with a thick unsaturated zone. Consequently, we conclude that whether a site is carbonate-rich or carbonate-poor is unimportant, as the influence of seawater will prevent decalcification, creating a low risk of mobilisation

  16. Paired hormone response elements predict caveolin-1 as a glucocorticoid target gene.

    Directory of Open Access Journals (Sweden)

    Marinus F van Batenburg

    2010-01-01

    Full Text Available Glucocorticoids act in part via glucocorticoid receptor binding to hormone response elements (HREs, but their direct target genes in vivo are still largely unknown. We developed the criterion that genomic occurrence of paired HREs at an inter-HRE distance less than 200 bp predicts hormone responsiveness, based on synergy of multiple HREs, and HRE information from known target genes. This criterion predicts a substantial number of novel responsive genes, when applied to genomic regions 10 kb upstream of genes. Multiple-tissue in situ hybridization showed that mRNA expression of 6 out of 10 selected genes was induced in a tissue-specific manner in mice treated with a single dose of corticosterone, with the spleen being the most responsive organ. Caveolin-1 was strongly responsive in several organs, and the HRE pair in its upstream region showed increased occupancy by glucocorticoid receptor in response to corticosterone. Our approach allowed for discovery of novel tissue specific glucocorticoid target genes, which may exemplify responses underlying the permissive actions of glucocorticoids.

  17. Joining elements of silicon carbide

    International Nuclear Information System (INIS)

    Olson, B.A.

    1979-01-01

    A method of joining together at least two silicon carbide elements (e.g.in forming a heat exchanger) is described, comprising subjecting to sufficiently non-oxidizing atmosphere and sufficiently high temperature, material placed in space between the elements. The material consists of silicon carbide particles, carbon and/or a precursor of carbon, and silicon, such that it forms a joint joining together at least two silicon carbide elements. At least one of the elements may contain silicon. (author)

  18. Development of a Cl-impregnated activated carbon for entrained-flow capture of elemental mercury.

    Science.gov (United States)

    Ghorishi, S Behrooz; Keeney, Robert M; Serre, Shannon D; Gullett, Brian K; Jozewicz, Wojciech S

    2002-10-15

    Efforts to discern the role of an activated carbon's surface functional groups on the adsorption of elemental mercury (Hg0) and mercuric chloride demonstrated that chlorine (Cl) impregnation of a virgin activated carbon using dilute solutions of hydrogen chloride leads to increases (by a factor of 2-3) in fixed-bed capture of these mercury species. A commercially available activated carbon (DARCO FGD, NORITAmericas Inc. [FGD])was Cl-impregnated (Cl-FGD) [5 lb (2.3 kg) per batch] and tested for entrained-flow, short-time-scale capture of Hg0. In an entrained flow reactor, the Cl-FGD was introduced in Hg0-laden flue gases (86 ppb of Hg0) of varied compositions with gas/solid contact times of about 3-4 s, resulting in significant Hg0 removal (80-90%), compared to virgin FGD (10-15%). These levels of Hg0 removal were observed across a wide range of very low carbon-to-mercury weight ratios (1000-5000). Variation of the natural gas combustion flue gas composition, by doping with nitrogen oxides and sulfur dioxide, and the flow reactor temperature (100-200 degrees C) had minimal effects on Hg0 removal bythe Cl-FGD in these carbon-to-mercury weight ratios. These results demonstrate significant enhancement of activated carbon reactivity with minimal treatment and are applicable to combustion facilities equipped with downstream particulate matter removal such as an electrostatic precipitator.

  19. Carbon photonics

    Energy Technology Data Exchange (ETDEWEB)

    Konov, V I [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-11-30

    The properties of new carbon materials (single-crystal and polycrystalline CVD diamond films and wafers, single-wall carbon nanotubes and graphene) and the prospects of their use as optical elements and devices are discussed. (optical elements of laser devices)

  20. Ambient organic carbon to elemental carbon ratios: Influence of the thermal–optical temperature protocol and implications

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yuan, E-mail: ycheng@mail.tsinghua.edu.cn [State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing (China); He, Ke-bin, E-mail: hekb@tsinghua.edu.cn [State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing (China); State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing (China); Duan, Feng-kui; Du, Zhen-yu [State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing (China); Zheng, Mei [College of Environmental Sciences and Engineering, Peking University, Beijing (China); Ma, Yong-liang [State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing (China)

    2014-01-01

    Ambient organic carbon (OC) to elemental carbon (EC) ratios are strongly associated with not only the radiative forcing due to aerosols but also the extent of secondary organic aerosol (SOA) formation. An inter-comparison study was conducted based on fine particulate matter samples collected during summer in Beijing to investigate the influence of the thermal–optical temperature protocol on the OC to EC ratio. Five temperature protocols were used such that the NIOSH (National Institute for Occupational Safety and Health) and EUSAAR (European Supersites for Atmospheric Aerosol Research) protocols were run by the Sunset carbon analyzer while the IMPROVE (the Interagency Monitoring of Protected Visual Environments network)-A protocol and two alternative protocols designed based on NIOSH and EUSAAR were run by the DRI analyzer. The optical attenuation measured by the Sunset carbon analyzer was more easily biased by the shadowing effect, whereas total carbon agreed well between the Sunset and DRI analyzers. The EC{sub IMPROVE-A} (EC measured by the IMPROVE-A protocol; similar hereinafter) to EC{sub NIOSH} ratio and the EC{sub IMPROVE-A} to EC{sub EUSAAR} ratio averaged 1.36 ± 0.21 and 0.91 ± 0.10, respectively, both of which exhibited little dependence on the biomass burning contribution. Though the temperature protocol had substantial influence on the OC to EC ratio, the contributions of secondary organic carbon (SOC) to OC, which were predicted by the EC-tracer method, did not differ significantly among the five protocols. Moreover, the SOC contributions obtained in this study were comparable with previous results based on field observation (typically between 45 and 65%), but were substantially higher than the estimation provided by an air quality model (only 18%). The comparison of SOC and WSOC suggests that when using the transmittance charring correction, all of the three common protocols (i.e., IMPROVE-A, NIOSH and EUSAAR) could be reliable for the estimation

  1. Ambient organic carbon to elemental carbon ratios: Influence of the thermal–optical temperature protocol and implications

    International Nuclear Information System (INIS)

    Cheng, Yuan; He, Ke-bin; Duan, Feng-kui; Du, Zhen-yu; Zheng, Mei; Ma, Yong-liang

    2014-01-01

    Ambient organic carbon (OC) to elemental carbon (EC) ratios are strongly associated with not only the radiative forcing due to aerosols but also the extent of secondary organic aerosol (SOA) formation. An inter-comparison study was conducted based on fine particulate matter samples collected during summer in Beijing to investigate the influence of the thermal–optical temperature protocol on the OC to EC ratio. Five temperature protocols were used such that the NIOSH (National Institute for Occupational Safety and Health) and EUSAAR (European Supersites for Atmospheric Aerosol Research) protocols were run by the Sunset carbon analyzer while the IMPROVE (the Interagency Monitoring of Protected Visual Environments network)-A protocol and two alternative protocols designed based on NIOSH and EUSAAR were run by the DRI analyzer. The optical attenuation measured by the Sunset carbon analyzer was more easily biased by the shadowing effect, whereas total carbon agreed well between the Sunset and DRI analyzers. The EC IMPROVE-A (EC measured by the IMPROVE-A protocol; similar hereinafter) to EC NIOSH ratio and the EC IMPROVE-A to EC EUSAAR ratio averaged 1.36 ± 0.21 and 0.91 ± 0.10, respectively, both of which exhibited little dependence on the biomass burning contribution. Though the temperature protocol had substantial influence on the OC to EC ratio, the contributions of secondary organic carbon (SOC) to OC, which were predicted by the EC-tracer method, did not differ significantly among the five protocols. Moreover, the SOC contributions obtained in this study were comparable with previous results based on field observation (typically between 45 and 65%), but were substantially higher than the estimation provided by an air quality model (only 18%). The comparison of SOC and WSOC suggests that when using the transmittance charring correction, all of the three common protocols (i.e., IMPROVE-A, NIOSH and EUSAAR) could be reliable for the estimation of SOC by the EC

  2. Influence of carbon and lipid sources on variation of mercury and other trace elements in polar bears (Ursus maritimus).

    Science.gov (United States)

    Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; McKinney, Melissa A; Peacock, Elizabeth; Sonne, Christian

    2012-12-01

    In the present study, the authors investigated the influence of carbon and lipid sources on regional differences in liver trace element (As, Cd, Cu, total Hg, Mn, Pb, Rb, Se, and Zn) concentrations measured in polar bears (Ursus maritimus) (n = 121) from 10 Alaskan, Canadian Arctic, and East Greenland subpopulations. Carbon and lipid sources were assessed using δ(13) C in muscle tissue and fatty acid (FA) profiles in subcutaneous adipose tissue as chemical tracers. A negative relationship between total Hg and δ(13) C suggested that polar bears feeding in areas with higher riverine inputs of terrestrial carbon accumulate more Hg than bears feeding in areas with lower freshwater input. Mercury concentrations were also positively related to the FA 20:1n-9, which is biosynthesized in large amounts in Calanus copepods. This result raises the hypothesis that Calanus glacialis are an important link in the uptake of Hg in the marine food web and ultimately in polar bears. Unadjusted total Hg, Se, and As concentrations showed greater geographical variation among polar bear subpopulations compared with concentrations adjusted for carbon and lipid sources. The Hg concentrations adjusted for carbon and lipid sources in Bering-Chukchi Sea polar bear liver tissue remained the lowest among subpopulations. Based on these findings, the authors suggest that carbon and lipid sources for polar bears should be taken into account when one is assessing spatial and temporal trends of long-range transported trace elements. Copyright © 2012 SETAC.

  3. THE EFFECT OF WATER (VAPOR-PHASE) AND CARBON ON ELEMENTAL MERCURY REMOVAL IN A FLOW REACTOR

    Science.gov (United States)

    The paper gives results of studying the effect of vapor-phase moisture on elemental mercury (Hgo) removal by activated carbon (AC) in a flow reactor. tests involved injecting AC into both a dry and a 4% moisture nitrogen (N2) /Hgo gas stream. A bituminous-coal-based AC (Calgon WP...

  4. 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)

  5. Influence of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in bicarbonate/carbonate buffer solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.G. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Tubular Goods Research Center of CNPC, Xi' an 710065 (China)], E-mail: dangguoli78@yahoo.com.cn; Feng, Y.R.; Bai, Z.Q. [Tubular Goods Research Center of CNPC, Xi' an 710065 (China); Zhu, J.W.; Zheng, M.S. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2007-11-01

    The influences of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in NaHCO{sub 3}/Na{sub 2}CO{sub 3} buffer solution are investigated by capacitance measurement and electrochemical impedance spectroscopy (EIS). The results show that the passive film appears n-type semiconductive character; with increasing the solution temperature, the addition of chromium into carbon steel and increasing the concentration of chloride ions, the slopes of Mott-Schottky plots decrease, which indicates the increment of the defect density in the passive film. EIS results show that the transfer impedance R{sub 1} and the diffusion impedance W decrease with increasing the solution temperature, with the addition of chromium into carbon steel and with increasing the chloride ions concentration. It can be concluded that the corrosion protection effect of passive film on the substrate decreases with increasing the solution temperature, adding chromium into carbon steel and increasing chloride ions concentration.

  6. A molecular-mechanics based finite element model for strength prediction of single wall carbon nanotubes

    International Nuclear Information System (INIS)

    Meo, M.; Rossi, M.

    2007-01-01

    The aim of this work was to develop a finite element model based on molecular mechanics to predict the ultimate strength and strain of single wallet carbon nanotubes (SWCNT). The interactions between atoms was modelled by combining the use of non-linear elastic and torsional elastic spring. In particular, with this approach, it was tried to combine the molecular mechanics approach with finite element method without providing any not-physical data on the interactions between the carbon atoms, i.e. the CC-bond inertia moment or Young's modulus definition. Mechanical properties as Young's modulus, ultimate strength and strain for several CNTs were calculated. Further, a stress-strain curve for large deformation (up to 70%) is reported for a nanotube Zig-Zag (9,0). The results showed that good agreement with the experimental and numerical results of several authors was obtained. A comparison of the mechanical properties of nanotubes with same diameter and different chirality was carried out. Finally, the influence of the presence of defects on the strength and strain of a SWNT was also evaluated. In particular, the stress-strain curve a nanotube with one-vacancy defect was evaluated and compared with the curve of a pristine one, showing a reduction of the ultimate strength and strain for the defected nanotube. The FE model proposed demonstrate to be a reliable tool to simulate mechanical behaviour of carbon nanotubes both in the linear elastic field and the non-linear elastic field

  7. Air pollution studies in terms of particulate matters, elements and black carbon in the aerosols collected at Andravoahangy-Antananarivo

    International Nuclear Information System (INIS)

    HARINOELY, M.

    2012-01-01

    This work was performed at the Institut National des Sciences et Techniques Nucleaires (Madagascar-INSTN) in the framework of RAF/4/019 project organized by the International Atomic Energy Agency. The main objective of this work is to study the level of air pollution in terms of particulate matters, elements and black carbon in the site of Andravoahangy-Antananarivo and to transmit the results obtained to the competent authorities so that they can make decisions to reduce the impacts of air pollution on the population. The total reflection X-ray fluorescence spectrometer is used for qualitative and quantitative analyses of the elements contained in the aerosols and the reflectometer M43D for the determination of the black carbon concentrations. The results showed that the average concentrations of the particulate matters PM 2,5-10 are higher than those of PM 2,5 . The average concentrations of PM 10 in the aerosols are exceeding the World Health Organisation (WHO) and European Union guidelines, set at 50 μg.m -3 and those of PM 2,5 are higher than the 2005 WHO (25 μg.m -3 ) and the United States Environmental Protection Agency (35 μg.m -3 ) guidelines. The identified elements in the aerosols are Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr and Pb. The average concentrations of these elements are also higher in the coarse particles than in the fine particles. The concentrations of black carbon are higher in the fine particles, with a maximum value of 9.12 μg.m -3 . [fr

  8. 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.

  9. 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.

  10. Using the Nova target chamber for high-yield targets

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1987-01-01

    The existing 2.2-m-radius Nova aluminum target chamber, coated and lined with boron-seeded carbon shields, is proposed for use with 1000-MJ-yield targets in the next laser facility. The laser beam and diagnostic holes in the target chamber are left open and the desired 10 -2 Torr vacuum is maintained both inside and outside the target chamber; a larger target chamber room is the vacuum barrier to the atmosphere. The hole area available is three times that necessary to maintain a maximum fluence below 12 J/cm 2 on optics placed at a radius of 10 m. Maximum stress in the target chamber wall is 73 MPa, which complies with the intent of the ASME Pressure Vessel Code. However, shock waves passing through the inner carbon shield could cause it to comminute. We propose tests and analyses to ensure that the inner carbon shield survives the environment. 13 refs

  11. Mobilisation of toxic trace elements under various beach nourishments

    International Nuclear Information System (INIS)

    Pit, Iris R.; Dekker, Stefan C.; Kanters, Tobias J.; Wassen, Martin J.; Griffioen, Jasper

    2017-01-01

    To enhance protection and maintain wide beaches for recreation, beaches are replenished with sand: so-called beach nourishments. We compared four sites: two traditional beach nourishments, a mega beach nourishment and a reference without beach nourishment. Two sites contain calcareous-rich sand, whereas the other two sites have calcareous-poor sand. We aimed to understand hydrogeochemical processes to indicate factors critical for the mobility of trace elements at nourishments. We therefore analysed the chemical characteristics of sediment and pore water to ascertain the main drivers that mobilise toxic trace elements. With Dutch Quality Standards for soil and groundwater, the characteristics of sediment and pore water were compared to Target Values (the values at which there is a sustainable soil quality) and Intervention Values (the threshold above which the soil's functions are at risk). The pore water characteristics revealed that Target Values were regularly exceeded, especially for the nourishment sites and mainly for Mo (78%), Ni (24%), Cr (55%), and As (21%); Intervention Values for shallow groundwater were occasionally exceeded for As (2%), Cr (2%) and Zn (2%). The sediment characteristics did not exceed the Target Values and showed that trace elements were mainly present in the fine fraction of <150 μm. The oxidation of sulphide minerals such as pyrite resulted into the elevated concentration for all nourishment sites, especially when an unsaturated zone was present and influence of rainwater was apparent. To prevent trace metal mobility at a mega beach nourishment it is important to retain seawater influences and limit oxidation processes. In this respect, a shoreface nourishment is recommended rather than a mega beach nourishment with a thick unsaturated zone. Consequently, we conclude that whether a site is carbonate-rich or carbonate-poor is unimportant, as the influence of seawater will prevent decalcification, creating a low risk of

  12. Carbon allocation and element composition in four Chlamydomonas mutants defective in genes related to the CO2 concentrating mechanism.

    Science.gov (United States)

    Memmola, Francesco; Mukherjee, Bratati; Moroney, James V; Giordano, Mario

    2014-09-01

    Four mutants of Chlamydomonas reinhardtii with defects in different components of the CO2 concentrating mechanism (CCM) or in Rubisco activase were grown autotrophically at high pCO2 and then transferred to low pCO2, in order to study the role of different components of the CCM on carbon allocation and elemental composition. To study carbon allocation, we measured the relative size of the main organic pools by Fourier Transform Infrared spectroscopy. Total reflection X-ray fluorescence was used to analyze the elemental composition of algal cells. Our data show that although the organic pools increased their size at high CO2 in all strains, their stoichiometry was highly homeostatic, i.e., the ratios between carbohydrates and proteins, lipid and proteins, and carbohydrates and lipids, did not change significantly. The only exception was the wild-type 137c, in which proteins decreased relative to carbohydrates and lipids, when the cells were transferred to low CO2. It is noticeable that the two wild types used in this study responded differently to the transition from high to low CO2. Malfunctions of the CCM influenced the concentration of several elements, somewhat altering cell elemental stoichiometry: especially the C/P and N/P ratios changed appreciably in almost all strains as a function of the growth CO2 concentration, except in 137c and the Rubisco activase mutant rca1. In strain cia3, defective in the lumenal carbonic anhydrase (CA), the cell quotas of P, S, Ca, Mn, Fe, and Zn were about 5-fold higher at low CO2 than at high CO2. A Principle Components Analysis showed that, mostly because of its elemental composition, cia3 behaved in a substantially different way from all other strains, at low CO2. The lumenal CA thus plays a crucial role, not only for the correct functioning of the CCM, but also for element utilization. Not surprisingly, growth at high CO2 attenuated differences among strains.

  13. 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.

  14. 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...

  15. Optimization of soft x-ray line emission from laser-produced carbon ...

    Indian Academy of Sciences (India)

    Intense XUV soft x-ray emission from laser-produced plasma sources is currently ... absorption edges of oxygen and carbon respectively) is particularly attractive as it permits ... ability of the target element producing intense discrete lines in the water .... ficient due to Pert [17] and dielectronic recombination coefficient due to ...

  16. Charge-based fractionation of oxyanion-forming metals and metalloids leached from recycled concrete aggregates of different degrees of carbonation: a comparison of laboratory and field leaching tests.

    Science.gov (United States)

    Mulugeta, Mesay; Engelsen, Christian J; Wibetoe, Grethe; Lund, Walter

    2011-02-01

    The release and charge-based fractionation of As, Cr, Mo, Sb, Se and V were evaluated in leachates generated from recycled concrete aggregates (RCA) in a laboratory and at a field site. The leachates, covering the pH range 8.4-12.6, were generated from non-carbonated, and artificially and naturally carbonated crushed concrete samples. Comparison between the release of the elements from the non-carbonated and carbonated samples indicated higher solubility of the elements from the latter. The laboratory leaching tests also revealed that the solubility of the elements is low at the "natural pH" of the non-carbonated materials and show enhancement when the pH is decreased. The charge-based fractionation of the elements was determined by ion-exchange solid phase extraction (SPE); it was found that all the target elements predominantly existed as anions in both the laboratory and field leachates. The high fraction of the anionic species of the elements in the leachates from the carbonated RCA materials verified the enhanced solubility of the oxyanionic species of the elements as a result of carbonation. The concentrations of the elements in the leachates and SPE effluents were determined by inductively coupled plasma mass spectrometry (ICP-MS). Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. PERSONAL, INDOOR, AND OUTDOOR CONCENTRATIONS OF PM2.5, PARTICULATE NITRATE, AND ELEMENTAL CARBON FOR INDIVIDUALS WITH COPD IN LOS ANGELES, CA

    Science.gov (United States)

    This study characterizes the personal, indoor, and outdoor concentrations of PM2.5 and the major components of PM2.5, including nitrate (NO3-), elemental carbon (EC), and the elements for individuals with chronic obstructive pulmonary disease (COPD) living in Los Angeles, CA. ...

  18. 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.

  19. Measurement of Gas and Volatile Elements Production Cross Section in a Molten Lead-Bismuth Target

    CERN Multimedia

    2002-01-01

    MEGAPIE is a project for a 1 MW liquid PbBi spallation source, to be built at the SINQ facility at the Paul Scherrer Institut, which will be an important step in the roadmap towards the demonstration of the ADS concept and high power molten metal targets in general. In the design and construction of such a challenging project it is extremely important to evaluate the amount and type of gas and volatile elements which will be produced, for a reliable and safe operation of the experiment. Both stable (H, $^{4}$He and other noble gases) and radioactive isotopes are of interest. Currently, different design options are under consideration to deal with the gas produced during operation. \\\\ For a correct estimation of the production cross sections, a measurement with a liquid PbBi target and a proton beam of energy close to the one of MEGAPIE (575 MeV) is necessary. We would like to use the ISOLDE facility, which offers the unique opportunity via its mass spectrometric analysis of the elements present in the gas pha...

  20. Sampling artifacts in measurement of elemental and organic carbon: Low-volume sampling in indoor and outdoor environments

    Science.gov (United States)

    Olson, David A.; Norris, Gary A.

    Experiments were completed to determine the extent of artifacts from sampling elemental carbon (EC) and organic carbon (OC) under sample conditions consistent with personal sampling. Two different types of experiments were completed; the first examined possible artifacts from oils used in personal environmental monitor (PEM) impactor plates, and the second examined artifacts from microenvironmental sampling using different sampling media combinations (quartz, Teflon, XAD denuder, and electrostatic precipitator). The effectiveness of front and backup filters was evaluated for most sampling configurations. Mean total carbon concentrations from sampling configurations using impactor oils were not statistically different from the control case (using a sharp cut cyclone). Three microenvironments were tested (kitchen, library, and ambient); carbon concentrations were highest in the kitchen using a front quartz filter (mean OC of 16.4 μg m -3). The lowest front quartz filter concentrations were measured in the library using XAD denuders (mean OC of 3.6 μg m -3). Denuder removal efficiencies (average of 82% for total carbon) were lower compared with previous ambient studies and may indicate that indoor sources influenced denuder efficiency during sample collection. The highest carbon concentrations from backup quartz filters were measured using the Teflon-quartz combination.

  1. 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.

  2. The manufacture of MTR fuel elements and Mo99 production targets at Dounreay

    International Nuclear Information System (INIS)

    Gibson, J.

    1997-01-01

    Uranium/aluminium alloy elements have been produced at Dounreay for nearly 40 years. In April 1990 the two DIDO-type reactors operated by the United Kingdom Atomic Energy Authority (UKAEA) at Harwell were closed, with the result that a large portion of the then current customer base disappeared and, to satisfy the needs of the evolving market, the decision was taken to invest over 1m pounds in new equipment for the manufacture of dispersed fuels and molybdenum production targets. (author)

  3. 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

  4. Single-experiment simultaneous-measurement of elemental mass-attenuation coefficients of hydrogen, carbon and oxygen for 0.123-1.33 MeV gamma rays

    International Nuclear Information System (INIS)

    Teli, M.T.; Nathuram, R.; Mahajan, C.S.

    2000-01-01

    As it is inconvenient to use elements like hydrogen, carbon and oxygen in pure forms for measurement of their gamma mass-attenuation coefficients, the measurements are to be done indirectly, by using compounds of the elements or a mixture of them. We give here a simple method of measuring the total mass-attenuation coefficients μ/ρ of the elements in a compound simultaneously and in a single experiment through the measurements of the μ/ρ values of the concerned compounds and using the mixture rule. The method is applied for the measurement of μ/ρ of hydrogen, carbon and oxygen by using acetone, ethanol and 1-propanol. Our results (for E γ =0.123-1.33 MeV) are seen to be in better agreement with the theoretical values of Hubbell and Seltzer (1995) [Hubbell J.H. and Seltzer S.M. (1995). Tables of X-ray mass attenuation coefficients and mass energy-absorption coefficients 1 keV to 20 MeV for elements Z=1 to 92 and 48 additional substances of dosimetric interest. NISTIR 5632] as compared to the results of El-Kateb and Abdul-Hamid (1991) [El-Kateb, A.H., Abdul-Hamid, A.S., 1991. Photon attenuation coefficient study of some materials containing hydrogen, carbon, and oxygen. Appl. Rad. Isot. 42, 303-307

  5. Finite Element Modeling of Thermal Cycling Induced Microcracking in Carbon/Epoxy Triaxial Braided Composites

    Science.gov (United States)

    Zhang, Chao; Binienda, Wieslaw K.; Morscher, Gregory; Martin, Richard E.

    2012-01-01

    The microcrack distribution and mass change in PR520/T700s and 3502/T700s carbon/epoxy braided composites exposed to thermal cycling was evaluated experimentally. Acoustic emission was utilized to record the crack initiation and propagation under cyclic thermal loading between -55 C and 120 C. Transverse microcrack morphology was investigated using X-ray Computed Tomography. Different performance of two kinds of composites was discovered and analyzed. Based on the observations of microcrack formation, a meso-mechanical finite element model was developed to obtain the resultant mechanical properties. The simulation results exhibited a decrease in strength and stiffness with increasing crack density. Strength and stiffness reduction versus crack densities in different orientations were compared. The changes of global mechanical behavior in both axial and transverse loading conditions were studied. Keywords: Thermal cycles; Microcrack; Finite Element Model; Braided Composite

  6. Isotopic abundance analysis of carbon, nitrogen and sulfur with a combined elemental analyzer-mass spectrometer system

    International Nuclear Information System (INIS)

    Pichlmayer, F.; Blochberger, K.

    1988-01-01

    Stable isotope ratio measurements of carbon, nitrogen and sulfur are of growing interest as analytical tool in many fields of research, but applications were somewhat hindered in the past by the fact that cumbersome sample preparation was necessary. A method has therefore been developed, consisting in essential of coupling an elemental analyzer with an isotope mass spectrometer, enabling fast and reliable conversion of C-, N- and S-compounds in any solid or liquid sample into the measuring gases carbon dioxide, nitrogen and sulfur dioxide for on-line isotopic analysis. The experimental set-up and the main characteristics are described in short and examples of application in environmental research, food analysis and clinical diagnosis are given. (orig.)

  7. Power load limits of the WENDELSTEIN 7-X target elements-comparison of experimental results and design values for power loads up to the critical heat flux

    International Nuclear Information System (INIS)

    Greuner, H; Boeswirth, B; Boscary, J; Leuprecht, A; Plankensteiner, A

    2007-01-01

    The power load limits of the WENDELSTEIN7-X divertor target elements were experimentally evaluated with heat loads considerably exceeding the expected operating conditions. The water-cooled elements are designed for steady-state heat flux of 10 MW m -2 and to remove a power load up to 100 kW. The elements must allow a limited operation time at 12 MW m -2 steady-state and should not fail for short pulses of up to 15 MW m -2 for cooling conditions in the subcooled nucleate boiling regime. In the framework of the qualification phase, pre-series target elements were loaded up to 24 MW m -2 without loss of CFC tiles. A critical heat flux at the target of 31 MW m -2 was achieved. The paper discusses the results of the tests performed at the high heat flux test facility GLADIS. The experimental results compared to transient nonlinear fine element method (FEM) calculations confirm a high thermal safety margin of the target design sufficient for plasma operation in W7-X

  8. Elemental geochemistry and strontium-isotope stratigraphy of Cenomanian to Santonian neritic carbonates in the Zagros Basin, Iran

    Science.gov (United States)

    Navidtalab, Amin; Rahimpour-Bonab, Hossain; Huck, Stefan; Heimhofer, Ulrich

    2016-12-01

    A Neo-Tethyan upper Cenomanian-Santonian neritic carbonate ramp succession (Sarvak and Ilam formations), drilled in the Zagros Basin in southwest Iran, was investigated via detailed sedimentology, microfacies analysis, elemental geochemistry and Sr-isotope stratigraphy (SIS). The succession contains two exposure surfaces, which are known as the CT-ES and mT-ES (Cenomanian-Turonian and middle Turonian, respectively), and associated prominent negative carbon-isotope excursions that represent important regional stratigraphic marker horizons. Precise knowledge about the onset of platform exposure and the duration of the exposure-related hiatus, however, is currently lacking due to a rather low-resolved shallow-water biostratigraphic framework and a bulk carbonate carbon-isotope pattern that clearly differs from global Late Cretaceous reference curves. Therefore, the existing bio-chemostratigraphic framework was complemented by bulk carbonate strontium-isotope stratigraphy (SIS). As bulk carbonate material is in particular prone to diagenetic alteration, a careful selection of least altered samples has been carried out by means of elemental geochemistry and petrography. In contrast to what could be expected, the meteoric alteration of limestones beneath both exposure surfaces is not clearly expressed by increasing iron and manganese and coeval decreasing strontium contents. On the contrary, the impact of meteoric diagenesis is well illustrated via pronounced increases in Rb concentrations and concomitant prominent positive shifts to radiogenic strontium-isotope values, an observation that clearly reflects the decay of continentally derived 87Rb into 87Sr. Rubidium corrected strontium-isotope values place the CT-ES around the Cenomanian-Turonian boundary and point to an exposure duration of less than 0.4 Myr. This rather short-term CT-ES related hiatus is supported by petrographic evidence, which indicates a youth karstification stage of strata beneath the CT

  9. An evaluation of microwave-assisted fusion and microwave-assisted acid digestion methods for determining elemental impurities in carbon nanostructures using inductively coupled plasma optical emission spectrometry

    KAUST Repository

    Patole, Shashikant P.

    2015-10-21

    It is common for as-prepared carbon nanotube (CNT) and graphene samples to contain remnants of the transition metals used to catalyze their growth; contamination may also leave other trace elemental impurities in the samples. Although a full quantification of impurities in as-prepared samples of carbon nanostructures is difficult, particularly when trace elements are intercalated or encapsulated within a protective layer of graphitic carbon, reliable information is essential for reasons such as quantifying the adulteration of physico-chemical properties of the materials and for evaluating environmental issues. Here, we introduce a microwave-based fusion method to degrade single- and double-walled CNTs and graphene nanoplatelets into a fusion flux thereby thoroughly leaching all metallic impurities. Subsequent dissolution of the fusion product in diluted hydrochloric and nitric acid allowed us to identify their trace elemental impurities using inductively coupled plasma optical emission spectrometry. Comparisons of the results from the proposed microwave-assisted fusion method against those of a more classical microwave-assisted acid digestion approach suggest complementarity between the two that ultimately could lead to a more reliable and less costly determination of trace elemental impurities in carbon nanostructured materials. Graphical abstract A method for the complete digestion of carbon nanostructures has been demonstrated. Photographs (on the left side) show zirconium crucibles containing SWCNTs with flux of Na2CO3 and K2CO3, before and after microwave fusion; (on the right side) the appearance of the final solutions containing dissolved samples, from microwave-assisted fusion and microwave-assisted acid digestion. These solutions were used for determining the trace elemental impurities by ICP‒OES.

  10. Climate-change effects on soils: Accelerated weathering, soil carbon and elemental cycling

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla

    2015-04-01

    Climate change [i.e., high atmospheric carbon dioxide (CO2) concentrations (≥400 ppm); increasing air temperatures (2-4°C or greater); significant and/or abrupt changes in daily, seasonal, and inter-annual temperature; changes in the wet/dry cycles; intensive rainfall and/or heavy storms; extended periods of drought; extreme frost; heat waves and increased fire frequency] is and will significantly affect soil properties and fertility, water resources, food quantity and quality, and environmental quality. Biotic processes that consume atmospheric CO2, and create organic carbon (C) that is either reprocessed to CO2 or stored in soils are the subject of active current investigations, with great concern over the influence of climate change. In addition, abiotic C cycling and its influence on the inorganic C pool in soils is a fundamental global process in which acidic atmospheric CO2 participates in the weathering of carbonate and silicate minerals, ultimately delivering bicarbonate and Ca2+ or other cations that precipitate in the form of carbonates in soils or are transported to the rivers, lakes, and oceans. Soil responses to climate change will be complex, and there are many uncertainties and unresolved issues. The objective of the review is to initiate and further stimulate a discussion about some important and challenging aspects of climate-change effects on soils, such as accelerated weathering of soil minerals and resulting C and elemental fluxes in and out of soils, soil/geo-engineering methods used to increase C sequestration in soils, soil organic matter (SOM) protection, transformation and mineralization, and SOM temperature sensitivity. This review reports recent discoveries, identifies key research needs, and highlights opportunities offered by the climate-change effects on soils.

  11. Examination of W7-X target elements after high heat flux testing

    International Nuclear Information System (INIS)

    Missirlian, M.; Durocher, A.; Schlosser, J.; Greuner, H.; Schedler, B.

    2007-01-01

    Full text of publication follows: The target elements of Wendelstein 7-X (W7-X) divertor are designed to sustain a stationary heat flux of 10 MW/m 2 and to remove a maximum power load up to 100 kW. The plasma-facing material is made of CFC NB31 flat tiles bonded to a CuCrZr copper alloy water-cooled heat sink. Before launching the serial fabrication, pre-series activities aimed at qualifying the design, the manufacturing route, the relevant non-destructive examination (NDE) methods, and at defining the acceptance criteria for the serial production. High heat flux (HHF) testing is the central activity of this qualification phase and represents a fundamental tool to predict 'critical' defects assembling. Within the framework of this qualification activity, the reception tests performed in the transient infrared thermography test bed SATIR at CEA-Cadarache and HHF testing carried out in the ion beam facility GLADIS at IPP-Garching, exhibited some tiles with thermal inhomogeneities, which initiated and developed during high heat flux testing. Hence, studies were launched in order to better understand this behaviour during cyclic heat loading. This post testing examination was mainly focused on the interface between CFC flat tiles and CuCrZr heat sink to improve if necessary the current design. HHF thermal cycling tests at ∼10 MW/m 2 for 10 s pulse duration each, allowed to assess the performances of target elements and showed some tiles with hot spots close to the edge (stable or progressing). Finally, after the HHF experimental campaign, a comprehensive analysis of some tested elements was carried out by means of infrared thermography inspection SATIR and metallographic examinations. Afterwards correlations between the non destructive SATIR inspection, HHF testing GLADIS and metallographic observation were investigated to assess damage detection, to analyse defect propagation, and to adjust the acceptance criteria valuable for the serial production. This paper will

  12. Transient thermal finite element analysis of CFC–Cu ITER monoblock using X-ray tomography data

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Ll.M., E-mail: llion.evans@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom); Margetts, L. [School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Williamson Building, Manchester M13 9PL (United Kingdom); Casalegno, V. [Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Lever, L.M. [IT Services for Research, University of Manchester, Devonshire House, Oxford Road, Manchester M13 9PL (United Kingdom); Bushell, J.; Lowe, T.; Wallwork, A. [School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom); Young, P. [Simpleware Ltd., Bradninch Hall, Castle Street, Exeter EX4 3PL (United Kingdom); Lindemann, A. [NETZSCH-Gerätebau GmbH, Wittelsbacherstraße 42, D-95100 Selb, Bayern (Germany); Schmidt, M.; Mummery, P.M. [School of Mechanical, Aerospace and Civil Engineering (MACE), University of Manchester, Manchester M13 9PL (United Kingdom)

    2015-11-15

    Highlights: • Thermal performance of a fusion power heat exchange component was investigated. • Microstructures effecting performance were determined using X-ray tomography. • This data was used to perform a microstructurally faithful finite element analysis. • FEA demonstrated that manufacturing defects had an appreciable effect on performance. • This image-based modelling showed which regions could be targeted for improvements. - Abstract: The thermal performance of a carbon fibre composite-copper monoblock, a sub-component of a fusion reactor divertor, was investigated by finite element analysis. High-accuracy simulations were created using an emerging technique, image-based finite element modelling, which converts X-ray tomography data into micro-structurally faithful models, capturing details such as manufacturing defects. For validation, a case study was performed where the thermal analysis by laser flash of a carbon fibre composite-copper disc was simulated such that computational and experimental results could be compared directly. Results showed that a high resolution image-based simulation (102 million elements of 32 μm width) provided increased accuracy over a low resolution image-based simulation (0.6 million elements of 194 μm width) and idealised computer aided design simulations. Using this technique to analyse a monoblock mock-up, it was possible to detect and quantify the effects of debonding regions at the carbon fibre composite-copper interface likely to impact both component performance and expected lifetime. These features would not have been accounted for in idealised computer aided design simulations.

  13. Transient thermal finite element analysis of CFC–Cu ITER monoblock using X-ray tomography data

    International Nuclear Information System (INIS)

    Evans, Ll.M.; Margetts, L.; Casalegno, V.; Lever, L.M.; Bushell, J.; Lowe, T.; Wallwork, A.; Young, P.; Lindemann, A.; Schmidt, M.; Mummery, P.M.

    2015-01-01

    Highlights: • Thermal performance of a fusion power heat exchange component was investigated. • Microstructures effecting performance were determined using X-ray tomography. • This data was used to perform a microstructurally faithful finite element analysis. • FEA demonstrated that manufacturing defects had an appreciable effect on performance. • This image-based modelling showed which regions could be targeted for improvements. - Abstract: The thermal performance of a carbon fibre composite-copper monoblock, a sub-component of a fusion reactor divertor, was investigated by finite element analysis. High-accuracy simulations were created using an emerging technique, image-based finite element modelling, which converts X-ray tomography data into micro-structurally faithful models, capturing details such as manufacturing defects. For validation, a case study was performed where the thermal analysis by laser flash of a carbon fibre composite-copper disc was simulated such that computational and experimental results could be compared directly. Results showed that a high resolution image-based simulation (102 million elements of 32 μm width) provided increased accuracy over a low resolution image-based simulation (0.6 million elements of 194 μm width) and idealised computer aided design simulations. Using this technique to analyse a monoblock mock-up, it was possible to detect and quantify the effects of debonding regions at the carbon fibre composite-copper interface likely to impact both component performance and expected lifetime. These features would not have been accounted for in idealised computer aided design simulations.

  14. The stable isotope composition of nitrogen and carbon and elemental contents in modern and fossil seabird guano from Northern Chile - Marine sources and diagenetic effects.

    Directory of Open Access Journals (Sweden)

    Friedrich Lucassen

    Full Text Available Seabird excrements (guano have been preserved in the arid climate of Northern Chile since at least the Pliocene. The deposits of marine organic material in coastal areas potentially open a window into the present and past composition of the coastal ocean and its food web. We use the stable isotope composition of nitrogen and carbon as well as element contents to compare the principal prey of the birds, the Peruvian anchovy, with the composition of modern guano. We also investigate the impact of diagenetic changes on the isotopic composition and elemental contents of the pure ornithogenic sediments, starting with modern stratified deposits and extending to fossil guano. Where possible, 14C systematics is used for age information. The nitrogen and carbon isotopic composition of the marine prey (Peruvian anchovy of the birds is complex as it shows strong systematic variations with latitude. The detailed study of a modern profile that represents a few years of guano deposition up to present reveals systematic changes in nitrogen and carbon isotopic composition towards heavier values that increase with age, i.e. depth. Only the uppermost, youngest layers of modern guano show compositional affinity to the prey of the birds. In the profile, the simultaneous loss of nitrogen and carbon occurs by degassing, and non-volatile elements like phosphorous and calcium are passively enriched in the residual guano. Fossil guano deposits are very low in nitrogen and low in carbon contents, and show very heavy nitrogen isotopic compositions. One result of the study is that the use of guano for tracing nitrogen and carbon isotopic and elemental composition in the marine food web of the birds is restricted to fresh material. Despite systematic changes during diagenesis, there is little promise to retrieve reliable values of marine nitrogen and carbon signatures from older guano. However, the changes in isotopic composition from primary marine nitrogen isotopic

  15. Deposition techniques for the preparation of thin film nuclear targets

    International Nuclear Information System (INIS)

    Muggleton, A.H.F.

    1987-07-01

    This review commences with a brief description of the basic principles that regulate vacuum evaporation and the physical processes involved in thin film formation, followed by a description of the experimental methods used. The principle methods of heating the evaporant are detailed and the means of measuring and controlling the film thickness are elucidated. Types of thin film nuclear targets are considered and various film release agents are listed. Thin film nuclear target behaviour under ion-bombardment is described and the dependence of nuclear experimental results upon target thickness and uniformity is outlined. Special problems associated with preparing suitable targets for lifetime measurements are discussed. The causes of stripper-foil thickening and breaking under heavy-ion bombardment are considered. A comparison is made between foils manufactured by a glow discharge process and those produced by vacuum sublimation. Consideration is given to the methods of carbon stripper-foil manufacture and to the characteristics of stripper-foil lifetimes are considered. Techniques are described that have been developed for the fabrication of special targets, both from natural and isotopically enriched material, and also of elements that are either chemically unstable, or thermally unstable under irradiation. The reduction of metal oxides by the use of hydrogen or by utilising a metallothermic technique, and the simultaneous evaporation of reduced rare earth elements is described. A comprehensive list of the common targets is presented

  16. Effects of Alloying Elements (Cr, Mn) on Corrosion Properties of Carbon Steel in Synthetic Seawater

    International Nuclear Information System (INIS)

    Hyun, Youngmin; Kim, Heesan

    2016-01-01

    Effects of alloying elements, manganese and chromium, on corrosion resistance of carbon steel were examined using weight loss test and electrochemical tests (polarization test and electrochemical impedance spectroscopy (EIS)) in synthetic seawater at 60 ℃. The results from the weight loss test showed that chromium effectively improved corrosion resistance of carbon steel during the entire immersion time, but manganese improved corrosion resistance after the lowered corrosion resistance at the beginnings of immersion. Unlike the weight loss test, the electrochemical tests showed that the corrosion resistance did not increase with immersion time, in all the specimens. This disagreement is explained by the presence of rust involved in electrochemical reaction during electrochemical tests. The analysis of rust with transmission electron microscopy (TEM)−energy dispersive spectroscopy (EDS) showed that the amorphous-like rust layer located at the metal/rust interface with enriched alloying element (Cr, Mn) prevents diffusion of corrosive species into a metal/rust interface effectively, which leads to increased corrosion resistance. The initial corrosion behaviour is also affected by the rust types. In other words, manganese accelerated the formation of spinel oxides, negatively affecting corrosion resistance. Meanwhile, chromium accelerated the formation of goethite but impeded the formation of spinel oxides, positively affecting the corrosion resistance. From the above results, the corrosion resistance of steel is closely related with a rust type.

  17. Effects of Alloying Elements (Cr, Mn) on Corrosion Properties of Carbon Steel in Synthetic Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, Youngmin; Kim, Heesan [Hongik University, Sejong (Korea, Republic of)

    2016-02-15

    Effects of alloying elements, manganese and chromium, on corrosion resistance of carbon steel were examined using weight loss test and electrochemical tests (polarization test and electrochemical impedance spectroscopy (EIS)) in synthetic seawater at 60 ℃. The results from the weight loss test showed that chromium effectively improved corrosion resistance of carbon steel during the entire immersion time, but manganese improved corrosion resistance after the lowered corrosion resistance at the beginnings of immersion. Unlike the weight loss test, the electrochemical tests showed that the corrosion resistance did not increase with immersion time, in all the specimens. This disagreement is explained by the presence of rust involved in electrochemical reaction during electrochemical tests. The analysis of rust with transmission electron microscopy (TEM)−energy dispersive spectroscopy (EDS) showed that the amorphous-like rust layer located at the metal/rust interface with enriched alloying element (Cr, Mn) prevents diffusion of corrosive species into a metal/rust interface effectively, which leads to increased corrosion resistance. The initial corrosion behaviour is also affected by the rust types. In other words, manganese accelerated the formation of spinel oxides, negatively affecting corrosion resistance. Meanwhile, chromium accelerated the formation of goethite but impeded the formation of spinel oxides, positively affecting the corrosion resistance. From the above results, the corrosion resistance of steel is closely related with a rust type.

  18. Decrease of concentration and colloidal fraction of organic carbon and trace elements in response to the anomalously hot summer 2010 in a humic boreal lake

    International Nuclear Information System (INIS)

    Shirokova, L.S.; Pokrovsky, O.S.; Moreva, O.Yu.; Chupakov, A.V.; Zabelina, S.A.; Klimov, S.I.; Shorina, N.V.; Vorobieva, T.Ya.

    2013-01-01

    The colloidal distribution and size fractionation of organic carbon (OC), major elements and trace elements (TE) were studied in a seasonally stratified, organic-rich boreal lake, Lake Svyatoe, located in the European subarctic zone (NW Russia, Arkhangelsk region). This study took place over the course of 4 years in both winter and summer periods using an in situ dialysis technique (1 kDa, 10 kDa and 50 kDa) and traditional frontal filtration and ultrafiltration (5, 0.22 and 0.025 μm). We observed a systematic difference in dissolved elements and colloidal fractions between summer and winter periods with the highest proportion of organic and organo-ferric colloids (1 kDa–0.22 μm) observed during winter periods. The anomalously hot summer of 2010 in European Russia produced surface water temperatures of approximately 30 °C, which were 10° above the usual summer temperatures and brought about crucial changes in element speciation and size fractionation. In August 2010, the concentration of dissolved organic carbon (DOC) decreased by more than 30% compared to normal period, while the relative proportion of organic colloids decreased from 70–80% to only 20–30% over the full depth of the water column. Similarly, the proportion of colloidal Fe decreased from 90–98% in most summers and winters to approximately 60–70% in August 2010. During this hot summer, measurable and significant (> 30% compared to other periods) decreases in the colloidal fractions of Ca, Mg, Sr, Ba, Al, Ti, Ni, As, V, Co, Y, all rare earth elements (REEs), Zr, Hf, Th and U were also observed. In addition, dissolved ( 100 for Co), the second and third factors could have brought about the decrease of allochthonous DOC concentration as well as the concentration and proportion of organic and organo-mineral colloidal forms of non-essential low-soluble trace elements present in the form of organic colloids (Al, Y, Ti, Zr, Hf, Th, Pb, all REEs). It can be hypothesized that climate warming in

  19. Theoretical analysis of the alloying element effect on decarburization

    International Nuclear Information System (INIS)

    Elanskij, G.N.; Kudrin, V.A.; Akinfiev, S.I.

    1978-01-01

    On the basis of the laws of physical chemistry the alloying element (Ni, Cr, Mo, W, Co, Mn) effect on the kinetics and degree of decarburizing in iron melt with low carbon concentrations has been determined. The calculation of alloying element effect on the value of carbon diffusion coefficient and on the velocity changes in carbon oxidation rate has been carried out. It is shown that carbon diffusion coefficient and decarburization rate are detemined by two factors: thermodynamic, carbon activity change in the presence of alloying elements being accounted for and structural, dependending on the liquid metal structure and being determined by the viscosity activity of impurity. Experimental data are given, testifying that the introduction in the melt of such elements as Ni, Co, Cu, promotes a decrease in carbon content, as well as accelerates the decarburization process. W and Mo produce a poor effect, and Cr and Mn abruptly increase the value of minimum carbon content. Mo, Cr and W reduce the decarburization rate in the melt

  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. Finite Element Based Design Optimization of WENDELSTEIN 7-X Divertor Targets

    International Nuclear Information System (INIS)

    Plankensteiner, A.; Leuprecht, A.; Schedler, B.; Scheiber, K.; Greuner, H.

    2006-01-01

    In the fusion experiment WENDELSTEIN 7-X divertor plasma facing components have to withstand severe loading conditions. In general thermally induced mechanical stressing turns out to be most critical with respect to life time predictions of the component. In the specific case flat tiles of CFC grade NB31 are joined to the precipitation hardened CuCrZr heat sink by employing an active metal cast (AMC)-Cu as an interlayer between CFC and CuCrZr. Residual stresses resulting from the manufacturing process act as initial stresses in the subsequent operational heat flux loading. For the latter loading regime these stresses intrinsically are generated due to the large contrast in the CTE for CFC and Cu. Different design variants of those CFC flat tile armoured target elements have been analysed via the finite element package ABAQUS aiming at derivation of an optimized component design. The numerical study comprises variants with different degrees of tessellation of the CFC flat tile section, orientation of the CFC, lamellar design of the AMC-interlayer, and different designs of the cooling channels. The thermo-mechanical material characteristics are accounted for the finite element models with elastic-plastic properties being assigned to the metallic sections CuCrZr and AMC-Cu, respectively, and orthotropic nonlinear-elastic properties being used to the CFC section. The latter has been realized in form of a user-defined material subroutine that is used at the integration point level of the finite element model. In particular, twelve scalar-type damage parameters obeying their own evolution equations with respect to the loading history account for specific stress-strain relationships in the three principal material directions and planes with six damage parameters being used for normal loading under tensile and compressive stress states, respectively, and six parameters being used for shear loading. For the aim of model verification calculated surface temperatures, global

  2. 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

  3. Target costing as an element of the hard coal extraction cost planning process

    Directory of Open Access Journals (Sweden)

    Katarzyna Segeth-Boniecka

    2017-09-01

    Full Text Available Target costing as an element of the hard coal extraction cost planning process Striving for the efficiency of activities is of great significance in the management of hard coal extractive enterprises, which are constantly subjected to the process of restructuring. Effective cost management is an important condition of the increase in the efficiency of the researched business entities’ activity. One of the tools whose basic objective is conscious influencing cost levels is target costing. The aim of this article is to analyse the conditions of implementing target costing in the planning of hard coal extraction costs in hard coal mines in Poland. The subject area raises a topical and important problem of the scope of solutions concerning cost analysis in hard coal mines in Poland, which has not been thoroughly researched yet. To achieve the abovementioned aim, the theoretical works of the subject area have been referenced. The mine management process is difficult and requires the application of best suited and most modern tools, including those used in the planning process of hard coal extraction costs in order to support the economic efficiency of mining operations. The use of the target costing concept in the planning of hard coal mine operations aims to support the decision-making process, so as to achieve a specified level of economic efficiency of the operations carried out in a territorially designated site of hard coal extraction.

  4. Chemically modified carbon fibers and their applications

    International Nuclear Information System (INIS)

    Ermolenko, I.N.; Lyubliner, I.P.; Gulko, N.V.

    1990-01-01

    This book gives a comprehensive review about chemically modified carbon fibers (e.g. by incorporation of other elements) and is structured as follows: 1. Types of carbon fibers, 2. Structure of carbon fibers, 3. Properties of carbon fibers, 4. The cellulose carbonization process, 5. Formation of element-carbon fiber materials, 6. Surface modification of carbon fibers, and 7. Applications of carbon fibers (e.g. adsorbents, catalysts, constituents of composites). (MM)

  5. Evaluation of thermal optical analysis method of elemental carbon for marine fuel exhaust.

    Science.gov (United States)

    Lappi, Maija K; Ristimäki, Jyrki M

    2017-12-01

    The awareness of black carbon (BC) as the second largest anthropogenic contributor in global warming and an ice melting enhancer has increased. Due to prospected increase in shipping especially in the Arctic reliability of BC emissions and their invented amounts from ships is gaining more attention. The International Maritime Organization (IMO) is actively working toward estimation of quantities and effects of BC especially in the Arctic. IMO has launched work toward constituting a definition for BC and agreeing appropriate methods for its determination from shipping emission sources. In our study we evaluated the suitability of elemental carbon (EC) analysis by a thermal-optical transmittance (TOT) method to marine exhausts and possible measures to overcome the analysis interferences related to the chemically complex emissions. The measures included drying with CaSO 4, evaporation at 40-180ºC, H 2 O treatment, and variation of the sampling method (in-stack and diluted) and its parameters (e.g., dilution ratio, Dr). A reevaluation of the nominal organic carbon (OC)/EC split point was made. Measurement of residual carbon after solvent extraction (TC-C SOF ) was used as a reference, and later also filter smoke number (FSN) measurement, which is dealt with in a forthcoming paper by the authors. Exhaust sources used for collecting the particle sample were mainly four-stroke marine engines operated with variable loads and marine fuels ranging from light to heavy fuel oils (LFO and HFO) with a sulfur content range of carbon (PyC) from OC, affecting the accuracy of EC determination. Thus, uncertainty remained regarding the EC results from HFO fuels. The work supports one part of the decision making in black carbon (BC) determination methodology. If regulations regarding BC emissions from marine engines will be implemented in the future, a well-defined and at best unequivocal method of BC determination is required for coherent and comparable emission inventories and

  6. On-line coupling of the MAT 251 with a Carlo Erba elemental analyzer for carbon isotope ratio measurements

    International Nuclear Information System (INIS)

    Pichlmayer, F.

    1986-06-01

    For carbon isotope investigations with a moderate precision demand of about 0.2 per mil in the isotope ratio fast and reliable results are attained by on line combination of the ANA 1500 Elemental Analyzer and the MAT 251 Isotope Mass Spectrometer. The crucial point hereof is the gas splitting device. By proper design and adjustment of the analytical parameters, good sample efficiency and a sharp CO 2 bulk within the He stream is reached. The main characteristics of this combined equipment are described and some isotopic results of organic and anorganic carbon in lake sediment-samples are given as well as deltasup1 3 C-analyses of spiritous liquors. (Author)

  7. Pulsed TEA CO2 Laser Irradiation of Titanium in Nitrogen and Carbon Dioxide Gases

    Science.gov (United States)

    Ciganovic, J.; Matavulj, P.; Trtica, M.; Stasic, J.; Savovic, J.; Zivkovic, S.; Momcilovic, M.

    2017-12-01

    Surface changes created by interaction of transversely excited atmospheric carbon dioxide (TEA CO2) laser with titanium target/implant in nitrogen and carbon dioxide gas were studied. TEA CO2 laser operated at 10.6 μm, pulse length of 100 ns and fluence of ˜17 J/cm2 which was sufficient for inducing surface modifications. Induced changes depend on the gas used. In both gases the grain structure was produced (central irradiated zone) but its forms were diverse, (N2: irregular shape; CO2: hill-like forms). Hydrodynamic features at peripheral zone, like resolidified droplets, were recorded only in CO2 gas. Elemental analysis of the titanium target surface indicated that under a nitrogen atmosphere surface nitridation occurred. In addition, irradiation in both gases was followed by appearance of plasma in front of the target. The existence of plasma indicates relatively high temperatures created above the target surface offering a sterilizing effect.

  8. Elemental and organic carbon in flue gas particles of various wood combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaegauf, C.; Schmid, M.; Guentert, P.

    2005-12-15

    The airborne particulate matter (PM) in the environment is of ever increasing concern to authorities and the public. The major fractions of particles in wood combustion processes are in the size less than 1 micron, typically in the range of 30 to 300 nm. Of specific interest is the content of the elemental carbon (EC) and organic carbon (OC) in the particles since these substances are known for its particular potential as carcinogens. Various wood combustion systems have been analysed (wood chip boiler, pellet boiler, wood log boiler, wood stove and open fire). The sampling of the particles was done by mean of a multi-stage particle sizing sampler cascade impactor. The impactor classifies the particles collected according to their size. The 7 stages classify the particles between 0.4 and 9 microns aerodynamic diameter. The analytical method for determining the content of EC and OC in the particles is based on coulometry. The coulometer measures the conductivity of CO{sub 2} released by oxidation of EC in the samples at 650 {sup o}C. The OC content is determined by pyrolysis of the particle samples in helium atmosphere.

  9. Production of Al-Ti-C grain refiners with the addition of elemental carbon

    International Nuclear Information System (INIS)

    Gezer, Berke Turgay; Toptan, Fatih; Daglilar, Sibel; Kerti, Isil

    2010-01-01

    Grain refining process used in aluminium alloys, has an important role for preventing columnar, coarse grains and encouraging fine, equiaxed grain formation. Al-Ti-B grain refiners are widely used as aluminium grain refiners despite the problems in application Al-Ti-C refiners have an increasing demand in recent years. In the present work, Al-Ti-C grain refiners with different Ti:C ratios were produced by insitu method with the addition of elemental carbon. Microstructures were characterised by optic microscope and scanning electron microscope equipped with energy dispersive spectroscopy. The effects of temperature, holding time and Ti:C ratio on the grain refinement process were investigated and optimum conditions were determined.

  10. Results of the examinations of the W7-X pre-series target elements

    International Nuclear Information System (INIS)

    Boscary, J.; Boeswirth, B.; Greuner, H.; Streibl, B.; Missirlian, M.; Schlosser, J.; Schedler, B.; Scheiber, K.

    2006-01-01

    The highly heat-loaded area of the target plates of the WENDELSTEIN 7-X (W7-X) divertor is formed by 890 water-cooled target elements (TEs). This surface is designed to sustain a maximum stationary heat flux of 10 MW/m 2 and to remove a maximum power of 100 kW per element. Flat tiles made of CFC Sepcarb(r) NB31 are bonded to a CuCrZr heat sink. This joint is manufactured in two stages. In the first step, an OFHC copper interlayer is cast onto the tile by active metal casting (AMC(r)). At this stage, the joint copper-CFC is inspected by X-ray and lock-in thermography. In the second step, the AMC(r)-NB31 tiles are joined to CuCrZr. Two technologies have been investigated: electron beam welding (EBW) and hot isostatic pressing (HIP). The joint copper-CuCrZr is examined by ultrasonic method. At the end of the fabrication, the bond between the heat sink and the CFC tiles is inspected by thermography methods. The produced CFC NB31 material for W7-X showed a large scatter in the tensile strength in the ex-pitch direction in the range of 50 - 110 MPa. Pre-series TEs have been manufactured to qualify the design, the fabrication, the relevant non-destructive examinations (NDEs) and the delivered CFC for the serial production. The whole manufacturing route is validated if the delivered elements withstand operating conditions similar to those in W7-X in the high heat flux (HHF) test facility GLADIS without degradation of performance and integrity. HHF tests did not show any effect that could be attributed to the CFC grade or to the joining method. The HHF test results exhibited a high percentage of defective tiles, indicated by hot spots at the border of the CFC surface. Visual inspections after HHF tests have mostly correlated these spots to the initiation and /or propagation of cracks at the lateral edge of the tiles in CFC at the interface CFC-copper. The pre-series activities have been extended to reduce the stresses at the critical AMC(r) interface. By means of

  11. The carbon isotope ratios and contents of mineral elements in leaves of Chinese medicinal plants

    International Nuclear Information System (INIS)

    Lin Zhifang; Sun Guchou; Wang Wei

    1989-01-01

    Leaf carbon isotope ratios and 13 kinds of mineral elements were measured on 36 species of common Chinese medicinal plants in a subtropical monsoon forest of Ding Hu Shan in Guangdong Province. The .delta.13C value were from -26.4 to -32.6%, indicating that all of the species belonged the photosynthetic C3 types. The relative lower value of δ13C was observed in the life form of shrubs. The contents of 7 elements (N, P, K, Ca, Na Mg, Si) were dependent upon the species, life form, medicinal function and medicinal part. Herb type medicine and the used medicinal part of leaves or whole plant showed higher levels of above elements than the others. Among the nine groups with different medicinal functions, it was found that more nitrogen was in the leaves of medicinal plants for hemophthisis, hypertension and stomachic troubles, more phosphorus and potassium were in the leaves for cancer and snake bite medicines, but more calcium and magnesium were in the leaves for curing rheumatics. Ferric, aluminium and manganese were the main composition of microelements in leaves. There were higher content of ferric in leaves for hemophthisis medicine, higher zinc in leaves for cold and hypertension medicine, and higher Cup in leaves of stomachic medicine. It was suggested that the pattern of mineral elements in leaves of Chinese medicinal plants reflected the different properties of absorption and accumulation. Some additional effect due to the high content of certain element might be associated with the main function of that medicine

  12. Transplutonium elements - a literature survey

    International Nuclear Information System (INIS)

    Sivaramakrishnan, C.K.; Jadhav, A.V.

    1974-01-01

    The report surveys reported work on the discovery of transplutonium elements and their production through various methods like bombardment of heavy elements with charged ions, successive neutron captures on heavy elements in reactors and multiple neutron captures by heavy elements during nuclear explosions. Estimated yields of transplutonium elements in special targets irradiated in reactors, and also as byproducts from spent power reactor fuels are quoted. Various chemical procedures adopted for recovery of these elements from irradiated target and also from power reactor fuel reprocessing streams are described. A brief survey of shielded facilities available at various centres for transplutonium programmes is also included. Major uses of some of these heavy elements are described. (author)

  13. 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.

  14. Hydrothermal replacement of biogenic and abiogenic aragonite by Mg-carbonates - Relation between textural control on effective element fluxes and resulting carbonate phase

    Science.gov (United States)

    Jonas, Laura; Müller, Thomas; Dohmen, Ralf; Immenhauser, Adrian; Putlitz, Benita

    2017-01-01

    Dolomitization, i.e., the secondary replacement of calcite or aragonite (CaCO3) by dolomite (CaMg[CO3]2), is one of the most volumetrically important carbonate diagenetic processes. It occurs under near surface and shallow burial conditions and can significantly modify rock properties through changes in porosity and permeability. Dolomitization fronts are directly coupled to fluid pathways, which may be related to the initial porosity/permeability of the precursor limestone, an existing fault network or secondary porosity/permeability created through the replacement reaction. In this study, the textural control on the replacement of biogenic and abiogenic aragonite by Mg-carbonates, that are typical precursor phases in the dolomitization process, was experimentally studied under hydrothermal conditions. Aragonite samples with different textural and microstructural properties exhibiting a compact (inorganic aragonite single crystal), an intermediate (bivalve shell of Arctica islandica) and open porous structure (skeleton of coral Porites sp.) were reacted with a solution of 0.9 M MgCl2 and 0.015 M SrCl2 at 200 °C. The replacement of aragonite by a Ca-bearing magnesite and a Mg-Ca carbonate of non-stoichiometric dolomitic composition takes place via a dissolution-precipitation process and leads to the formation of a porous reaction front that progressively replaces the aragonite precursor. The reaction leads to the development of porosity within the reaction front and distinctive microstructures such as gaps and cavities at the reaction interface. The newly formed reaction rim consists of chemically distinct phases separated by sharp boundaries. It was found that the number of phases and their chemical variation decreases with increasing initial porosity and reactive surface area. This observation is explained by variations in effective element fluxes that result in differential chemical gradients in the fluid within the pore space of the reaction rim. Observed

  15. Permeable reactive barrier of surface hydrophobic granular activated carbon coupled with elemental iron for the removal of 2,4-dichlorophenol in water

    Energy Technology Data Exchange (ETDEWEB)

    Yang Ji, E-mail: yangji@ecust.edu.cn [School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237 (China); Cao Limei; Guo Rui; Jia Jinping [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-12-15

    Granular activated carbon was modified with dimethyl dichlorosilane to improve its surface hydrophobicity, and therefore to improve the performance of permeable reactive barrier constructed with the modified granular activated carbon and elemental iron. X-ray photoelectron spectroscopy shows that the surface silicon concentration of the modified granular activated carbon is higher than that of the original one, leading to the increased surface hydrophobicity. Although the specific surface area decreased from 895 to 835 m{sup 2} g{sup -1}, the modified granular activated carbon could adsorb 20% more 2,4-dichlorophenol than the original one did in water. It is also proven that the permeable reactive barrier with the modified granular activated carbon is more efficient at 2,4-dichlorophenol dechlorination, in which process 2,4-dichlorophenol is transformed to 2-chlorophenol or 4-chlorophenol then to phenol, or to phenol directly.

  16. Permeable reactive barrier of surface hydrophobic granular activated carbon coupled with elemental iron for the removal of 2,4-dichlorophenol in water

    International Nuclear Information System (INIS)

    Yang Ji; Cao Limei; Guo Rui; Jia Jinping

    2010-01-01

    Granular activated carbon was modified with dimethyl dichlorosilane to improve its surface hydrophobicity, and therefore to improve the performance of permeable reactive barrier constructed with the modified granular activated carbon and elemental iron. X-ray photoelectron spectroscopy shows that the surface silicon concentration of the modified granular activated carbon is higher than that of the original one, leading to the increased surface hydrophobicity. Although the specific surface area decreased from 895 to 835 m 2 g -1 , the modified granular activated carbon could adsorb 20% more 2,4-dichlorophenol than the original one did in water. It is also proven that the permeable reactive barrier with the modified granular activated carbon is more efficient at 2,4-dichlorophenol dechlorination, in which process 2,4-dichlorophenol is transformed to 2-chlorophenol or 4-chlorophenol then to phenol, or to phenol directly.

  17. Fossil and non-fossil sources of organic carbon (OC and elemental carbon (EC in Göteborg, Sweden

    Directory of Open Access Journals (Sweden)

    S. Szidat

    2009-03-01

    Full Text Available Particulate matter was collected at an urban site in Göteborg (Sweden in February/March 2005 and in June/July 2006. Additional samples were collected at a rural site for the winter period. Total carbon (TC concentrations were 2.1–3.6 μg m−3, 1.8–1.9 μg m−3, and 2.2–3.0 μg m−3 for urban/winter, rural/winter, and urban/summer conditions, respectively. Elemental carbon (EC, organic carbon (OC, water-insoluble OC (WINSOC, and water-soluble OC (WSOC were analyzed for 14C in order to distinguish fossil from non-fossil emissions. As wood burning is the single major source of non-fossil EC, its contribution can be quantified directly. For non-fossil OC, the wood-burning fraction was determined independently by levoglucosan and 14C analysis and combined using Latin-hypercube sampling (LHS. For the winter period, the relative contribution of EC from wood burning to the total EC was >3 times higher at the rural site compared to the urban site, whereas the absolute concentrations of EC from wood burning were elevated only moderately at the rural compared to the urban site. Thus, the urban site is substantially more influenced by fossil EC emissions. For summer, biogenic emissions dominated OC concentrations most likely due to secondary organic aerosol (SOA formation. During both seasons, a more pronounced fossil signal was observed for Göteborg than has previously been reported for Zurich, Switzerland. Analysis of air mass origin using back trajectories suggests that the fossil impact was larger when local sources dominated, whereas long-range transport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations of levoglucosan and other monosaccharide anhydrides were low for the urban and the rural site in the area of Göteborg during winter.

  18. Observed metre scale horizontal variability of elemental carbon in surface snow

    International Nuclear Information System (INIS)

    Svensson, J; Lihavainen, H; Ström, J; Hansson, M; Kerminen, V-M

    2013-01-01

    Surface snow investigated for its elemental carbon (EC) concentration, based on a thermal–optical method, at two different sites during winter and spring of 2010 demonstrates metre scale horizontal variability in concentration. Based on the two sites sampled, a clean and a polluted site, the clean site (Arctic Finland) presents the greatest variability. In side-by-side ratios between neighbouring samples, 5 m apart, a ratio of around two was observed for the clean site. The median for the polluted site had a ratio of 1.2 between neighbouring samples. The results suggest that regions exposed to snowdrift may be more sensitive to horizontal variability in EC concentration. Furthermore, these results highlight the importance of carefully choosing sampling sites and timing, as each parameter will have some effect on EC variability. They also emphasize the importance of gathering multiple samples from a site to obtain a representative value for the area. (letter)

  19. Impacts of low-carbon power policy on carbon mitigation in Guangdong Province, China

    International Nuclear Information System (INIS)

    Cheng, Beibei; Dai, Hancheng; Wang, Peng; Xie, Yang; Chen, Li; Zhao, Daiqing; Masui, Toshihiko

    2016-01-01

    This paper analyzes the impacts of the low-carbon policy in the power sector of Guangdong Province in China on its energy and carbon emission targets by 2020, as well as their costs and co-benefits, using a regional CGE model with seven scenarios: business as usual (BaU), renewable energy (RE), renewable energy and natural gas (RE–NG), CAP only (CAP), CAP and RE–NG (CAP–RE–NG), carbon emission trading (ETS), and ETS with RE–NG (ETS–RE–NG). Analysis results reveal that provincial energy and carbon intensity targets can be achieved in the assumed carbon mitigation scenarios with carbon cap, ETS, and clean energy development policies. While the carbon constraint exerts negative impacts on the economy, GDP loss could be lowered by the ETS and RE policies. The RE scenario is more economically efficient than the ETS scenario, and coupling the RE and ETS scenarios appears to be the most economically efficient scenario to achieve the desired carbon and energy intensity targets. One of the benefits of the low-carbon policy is its improvement of the energy security of Guangdong in terms of reduced reliance on external coal and oil; in particular, Guangdong coal consumption could peak in 2017–2019. - Highlights: • This study analyzes the low carbon policy in the power sector in Guangdong of China. • The role of power sector in achieving carbon and energy intensity target is shown. • Renewable energy and natural gas are very important for Guangdong Province. • Additional efforts in other sectors are needed to achieve the intensity targets. • The mitigation cost and economic impacts are assessed under various policy settings.

  20. Sub-barrier quasifission in heavy element formation reactions with deformed actinide target nuclei

    Science.gov (United States)

    Hinde, D. J.; Jeung, D. Y.; Prasad, E.; Wakhle, A.; Dasgupta, M.; Evers, M.; Luong, D. H.; du Rietz, R.; Simenel, C.; Simpson, E. C.; Williams, E.

    2018-02-01

    Background: The formation of superheavy elements (SHEs) by fusion of two massive nuclei is severely inhibited by the competing quasifission process. Low excitation energies favor SHE survival against fusion-fission competition. In "cold" fusion with spherical target nuclei near 208Pb, SHE yields are largest at beam energies significantly below the average capture barrier. In "hot" fusion with statically deformed actinide nuclei, this is not the case. Here the elongated deformation-aligned configurations in sub-barrier capture reactions inhibits fusion (formation of a compact compound nucleus), instead favoring rapid reseparation through quasifission. Purpose: To determine the probabilities of fast and slow quasifission in reactions with prolate statically deformed actinide nuclei, through measurement and quantitative analysis of the dependence of quasifission characteristics at beam energies spanning the average capture barrier energy. Methods: The Australian National University Heavy Ion Accelerator Facility and CUBE fission spectrometer have been used to measure fission and quasifission mass and angle distributions for reactions with projectiles from C to S, bombarding Th and U target nuclei. Results: Mass-asymmetric quasifission occurring on a fast time scale, associated with collisions with the tips of the prolate actinide nuclei, shows a rapid increase in probability with increasing projectile charge, the transition being centered around projectile atomic number ZP=14 . For mass-symmetric fission events, deviations of angular anisotropies from expectations for fusion fission, indicating a component of slower quasifission, suggest a similar transition, but centered around ZP˜8 . Conclusions: Collisions with the tips of statically deformed prolate actinide nuclei show evidence for two distinct quasifission processes of different time scales. Their probabilities both increase rapidly with the projectile charge. The probability of fusion can be severely

  1. 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

  2. Elemental conservation units: communicating extinction risk without dictating targets for protection.

    Science.gov (United States)

    Wood, Chris C; Gross, Mart R

    2008-02-01

    Conservation biologists mostly agree on the need to identify and protect biodiversity below the species level but have not yet resolved the best approach. We addressed 2 issues relevant to this debate. First, we distinguished between the abstract goal of preserving the maximum amount of unique biodiversity and the pragmatic goal of minimizing the loss of ecological goods and services given that further loss of biodiversity seems inevitable. Second, we distinguished between the scientific task of assessing extinction risk and the normative task of choosing targets for protection. We propose that scientific advice on extinction risk be given at the smallest meaningful scale: the elemental conservation unit (ECU). An ECU is a demographically isolated population whose probability of extinction over the time scale of interest (say 100 years) is not substantially affected by natural immigration from other populations. Within this time frame, the loss of an ECU would be irreversible without human intervention. Society's decision to protect an ECU ought to reflect human values that have social, economic, and political dimensions. Scientists can best inform this decision by providing advice about the probability that an ECU will be lost and the ecological and evolutionary consequences of that loss in a form that can be integrated into landscape planning. The ECU approach provides maximum flexibility to decision makers and ensures that the scientific task of assessing extinction risk informs, but remains distinct from, the normative social challenge of setting conservation targets.

  3. Galvanic element. Galvanisches Element

    Energy Technology Data Exchange (ETDEWEB)

    Sprengel, D.; Haelbig, H.

    1980-01-03

    The invention concerns a gas-tight sealed accumulator with positive and negative electrode plates and an auxillary electrode electroconductively bound to the latter for suppressing oxygen pressure. The auxillary electrode is an intermediate film electrode. The film catalysing oxygen reduction is hydrophilic in character and the other film is hydrophobic. A double coated foil has proved to be advantageous, the hydrophilic film being formed from polymer-bound activated carbon and the hydrophrobic film from porous polytetrafluoroethylene. A metallic network of silver or nickel is rolled into the outer side of the activated carbon film. This auxillary electrode can be used to advantage in all galvanic elements. Even primary cells fall within the scope of application for auxillary electrodes because many of these contain a highly oxidized electrodic material which tends to give off oxygen.

  4. Permeable reactive barrier of surface hydrophobic granular activated carbon coupled with elemental iron for the removal of 2,4-dichlorophenol in water.

    Science.gov (United States)

    Yang, Ji; Cao, Limei; Guo, Rui; Jia, Jinping

    2010-12-15

    Granular activated carbon was modified with dimethyl dichlorosilane to improve its surface hydrophobicity, and therefore to improve the performance of permeable reactive barrier constructed with the modified granular activated carbon and elemental iron. X-ray photoelectron spectroscopy shows that the surface silicon concentration of the modified granular activated carbon is higher than that of the original one, leading to the increased surface hydrophobicity. Although the specific surface area decreased from 895 to 835 m(2)g(-1), the modified granular activated carbon could adsorb 20% more 2,4-dichlorophenol than the original one did in water. It is also proven that the permeable reactive barrier with the modified granular activated carbon is more efficient at 2,4-dichlorophenol dechlorination, in which process 2,4-dichlorophenol is transformed to 2-chlorophenol or 4-chlorophenol then to phenol, or to phenol directly. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Dust, Elemental Carbon and Other Impurities on Central Asian Glaciers: Origin and Radiative Forcing

    Science.gov (United States)

    Schmale, J.; Flanner, M.; Kang, S.; Sprenger, M.; Zhang, Q.; Li, Y.; Guo, J.; Schwikowski, M.

    2015-12-01

    In Central Asia, more than 60 % of the population depends on water stored in glaciers and mountain snow. While temperature, precipitation and dynamic processes are key drivers of glacial change, deposition of light absorbing impurities such as mineral dust and black carbon can lead to accelerated melting through surface albedo reduction. Here, we discuss the origin of deposited mineral dust and black carbon and their impacts on albedo change and radiative forcing (RF). 218 snow samples were taken from 13 snow pits on 4 glaciers, Abramov (Pamir), Suek, Glacier No. 354 and Golubin (Tien Shan), representing deposition between summer 2012 and 2014. They were analyzed for elemental and organic carbon by a thermo-optical method, mineral dust by gravimetry, and iron by ICP-MS. Back trajectory ensembles were released every 6 hours with the Lagranto model for the covered period at all sites. Boundary layer "footprints" were calculated to estimate general source regions and combined with MODIS fire counts for potential fire contributions. Albedo reduction due to black carbon and mineral dust was calculated with the Snow-Ice-Aerosol-Radiative model (SNICAR), and surface spectral irradiances were derived from atmospheric radiative transfer calculations to determine the RF under clear-sky and all sky conditions using local radiation measurements. Dust contributions came from Central Asia, the Arabian Peninsula, the Sahara and partly the Taklimakan. Fire contributions were higher in 2014 and generally came from the West and North. We find that EC exerts roughly 3 times more RF than mineral dust in fresh and relatively fresh snow (~5 W/m2) and up to 6 times more in snow that experienced melting (> 10 W/m2) even though EC concentrations (average per snow pit from 90 to 700 ng/g) were up to two orders of magnitude lower than mineral dust (10 to 140 μg/g).

  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. A Low Carbon Development Guide for Local Government Actions in China

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Nina; Zhou, Nan; Price, Lynn; Ohshita, Stephanie

    2011-05-01

    Local level actions are crucial for achieving energy-saving and greenhouse gas emission reduction targets. Yet it is challenging to implement new policies and actions due to a lack of information, funding, and capacity. This is particularly the case in developing countries such as China. Even though national energy intensity and carbon intensity targets have been set, most local governments do not have the knowledge regarding actions to achieve the targets, the cost-effectiveness of policies, the possible impact of policies, or how to design and implement a climate action plan. This paper describes a guidebook that was developed to motivate and provide local governments in China with information to create an action plan to tackle climate change and increase energy efficiency. It provides a simple step-by-step description of how action plans can be established and essential elements to be included - from preparing a GHG emission inventory to implementation of the plan. The guidebook also provides a comprehensive list of successful policies and best practices found internationally and in China to encourage low carbon development in industry, buildings, transportation, electric power generation, agriculture and forestry. This paper also presents indicators that can be used to define low-carbon development, as well as to evaluate the effectiveness of actions taken at an aggregated (city) level, and at a sectoral or end use level. The guidebook can also be used for low carbon development by local governments in other developing countries.

  9. 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

  10. Results of the examinations of the W7-X pre-series target elements

    International Nuclear Information System (INIS)

    Boscary, J.; Boeswirth, B.; Greuner, H.; Missirlian, M.; Schedler, B.; Scheiber, K.; Schlosser, J.; Streibl, B.

    2007-01-01

    The target elements of the WENDELSTEIN 7-X (W7-X) divertor are designed to sustain a stationary heat flux of 10 MW/m 2 and to remove a maximum power of 100 kW. CFC Sepcarb NB31 tiles are bonded to a water-cooled CuCrZr heat sink in two steps: active metal casting (AMC) of an AMC -copper interlayer to CFC tiles, electron beam welding (EBW) or hot isostatic pressing (HIP) of the AMC -NB31 tiles to CuCrZr. The fabrication of the whole amount of CFC NB31 has been completed. The key target of the pre-series phase is the qualification of this bond based on a series of examinations. The introduction of silicon during the AMC process significantly improved the strength of the joint between CFC and AMC -copper. The strength of the bond is preserved after either EBW or HIP processes. High heat flux testing carried out in the ion beam facility GLADIS exhibited a too high percentage of defective tiles. Pre-series activities have been extended to reduce the stress concentration at the interface between tiles and heat sink by optimizing the design

  11. 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.

  12. 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.

  13. Carbon and oxygen stable isotope and trace element studies in speleothems and across the J-K boundary, Central Italy

    International Nuclear Information System (INIS)

    Kudielka, G.

    2001-07-01

    Carbon and Oxygen stable isotope ratios of carbonates decisively depend on fractionation during physicochemical processes. Therefore, they represent a powerful tool to derive information on past conditions under which the carbonates formed. Isotope ratio mass spectrometry (IRMS) offers a large range of applications. This thesis presents two projects based upon investigation of carbon and oxygen stable isotope ratios combined with trace element abundances (determined by instrumental neutron activation analysis, INAA) in carbonates. (1) Palaeoclimatic investigation on speleothems from central Italy. Four speleothems from Grotta Grande del Vento, central Italy, were analyzed for stable isotope ratios and trace element abundances, and age dated to obtain a chronologically reliable stable isotope profile. The speleothems were sampled by means of a dental drill to gain a stable isotope profile with a 0.5 mm resolution, trace element abundances have been performed by INAA every 0.5 cm, and the samples for age dating were picked according to remarkable features in the stable isotope trends and analyzed by TIMS. The record covers the period from 93 ka until the early holocene with a hiatus lasting from 75 ka until 65.0 ka. Speleothem growth during the last glacial indicates moderate conditions in the Frasassi region back then. Comparison with speleothems from Ireland, France and northern Italy reveal a north-south slope in d18O, indicating, that the rain over central Italy mainly originates from the North Atlantic. Depletion of moisture in d18O during its continental trajectory is due to rainout, which primarily extracts the heavy isotopes. The stable isotope record is in good agreement with the high-resolution speleothem record from Soreq Cave, Israel. Distinct isotopic events coincide between 85 ka and 80 ka, between ∼ 60 ka and 50 ka and from the last glacial to the early holocene. An offset has been existing between the two records at any time. The speleothems of

  14. Evaluation of the size segregation of elemental carbon (EC) emission in Europe: Influence on the simulation of EC long-range transportation

    NARCIS (Netherlands)

    Chen, Y.; Cheng, Y.F.; Nordmann, S.; Birmili, W.; Denier Van Der Gon, H.A.C.; Ma, N.; Wolke, R.; Wehner, B.; Sun, J.; Spindler, G.; Mu, Q.; Pöschl, U.; Su, H.; Wiedensohler, A.

    2016-01-01

    Elemental Carbon (EC) has a significant impact on human health and climate change. In order to evaluate the size segregation of EC emission in the EUCAARI inventory and investigate its influence on the simulation of EC long-range transportation in Europe, we used the fully coupled online Weather

  15. Applications of Lagrangian Dispersion Modeling to the Analysis of Changes in the Specific Absorption of Elemental Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Doran, J. C.; Fast, Jerome D.; Barnard, James C.; Laskin, Alexander; Desyaterik, Yury; Gilles, Marry K.; Hopkins, Rebecca J.

    2008-03-07

    We use a Lagrangian dispersion model driven by a mesoscale model with four-dimensional data assimilation to simulate the dispersion of elemental carbon (EC) over a region encompassing Mexico City and its surroundings, the study domain for the 2006 MAX-MEX experiment, which was a component of the MILAGRO campaign. The results are used to identify periods when biomass burning was likely to have had a significant impact on the concentrations of elemental carbon at two sites, T1 and T2, downwind of the city, and when emissions from the Mexico City Metropolitan Area (MCMA) were likely to have been more important. They are also used to estimate the median ages of EC affecting the specific absorption of light, aABS, at 870 nm as well as to identify periods when the urban plume from the MCMA was likely to have been advected over T1 and T2. Values of aABS at T1, the nearer of the two sites to Mexico City, were smaller at night and increased rapidly after mid-morning, peaking in the mid-afternoon. The behavior is attributed to the coating of aerosols with substances such as sulfate or organic carbon during daylight hours, but such coating appears to be limited or absent at night. Evidence for this is provided by scanning electron microscope images of aerosols collected at three sampling sites. During daylight hours the values of aABS did not increase with aerosol age for median ages in the range of 1-4 hours. There is some evidence for absorption increasing as aerosols were advected from T1 to T2 but the statistical significance of that result is not strong.

  16. 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

  17. Simulation of CNT-AFM tip based on finite element analysis for targeted probe of the biological cell

    Energy Technology Data Exchange (ETDEWEB)

    Yousefi, Amin Termeh, E-mail: at.tyousefi@gmail.com; Miyake, Mikio, E-mail: miyakejaist@gmail.com; Ikeda, Shoichiro, E-mail: sho16.ikeda@gmail.com [ChECA IKohza, Dept. Environmental & Green Technology (EGT), Malaysia, Japan International Institute of Technology (MJIIT), University Technology Malaysia - UTM, Kualalumpur (Malaysia); Mahmood, Mohamad Rusop, E-mail: nano@uitm.gmail.com [NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA (UiTM), Shah Alam, Selangor (Malaysia)

    2016-07-06

    Carbon nanotubes (CNTs) are potentially ideal tips for atomic force microscopy (AFM) due to the robust mechanical properties, nano scale diameter and also their ability to be functionalized by chemical and biological components at the tip ends. This contribution develops the idea of using CNTs as an AFM tip in computational analysis of the biological cell’s. Finite element analysis employed for each section and displacement of the nodes located in the contact area was monitored by using an output database (ODB). This reliable integration of CNT-AFM tip process provides a new class of high performance nanoprobes for single biological cell analysis.

  18. Determining Inorganic and Organic Carbon.

    Science.gov (United States)

    Koistinen, Jaana; Sjöblom, Mervi; Spilling, Kristian

    2017-11-21

    Carbon is the element which makes up the major fraction of lipids and carbohydrates, which could be used for making biofuel. It is therefore important to provide enough carbon and also follow the flow into particulate organic carbon and potential loss to dissolved organic forms of carbon. Here we present methods for determining dissolved inorganic carbon, dissolved organic carbon, and particulate organic carbon.

  19. Field evaluation of diesel particulate matter using portable elemental carbon monitors

    Energy Technology Data Exchange (ETDEWEB)

    Janisko, S.; Noll, J.D. [National Inst. for Occupational Safety and Health, Pittsburgh, PA (United States)

    2010-07-01

    The permissible exposure limits of underground mine workers to diesel particulate matter (DPM) was lowered in 2008 by the United States Mine Safety and Health Administration. In order to comply with the new regulation, most mines must use one or several combined control strategies to lower DPM concentrations. Since DPMs are complex and unpredictable, there is a need for new tools to help mines develop an effective strategy to reduce their concentrations. This paper reported on newly developed portable elemental carbon (EC) monitoring device for use in underground mines. This compact instrument was developed by the National Institute for Occupational Safety and Health to monitor EC concentrations in real time. The device has proven to be useful in planning new DPM curtailment strategies and in measuring the effectiveness of existing DPM controls. The information is provided in charts of concentration changes over time. The data offers a new way of understanding the factors that influence DPM exposure and drive concentration transients in an underground environment. 14 refs., 6 figs.

  20. Biogeochemistry of carbon and related major and trace elements in peat bog soils of the middle taiga of Western Siberia (Russia).

    Science.gov (United States)

    Stepanova, V. A.; Mironycheva-Tokareva, N. P.; Pokrovsky, O. S.

    2012-04-01

    Global climate changes impact the status of wetland ecosystems shifting the balances of the carbon, macro-, and microelements cycles. This study aims to establish the features of accumulation and distribution of major- and trace elements in the organic layer of peat bog soils, belonging to different ecosystems of the oligotrophic bog complex located in the middle taiga of Western Siberia (Khanty-Mansiysk region, Russia). Key areas which are selected for this study include the following bog conjugate elementary ecosystems: higher ryam, lower ryam, ridge-hollow complex, and oligotrophic poor fen as characterized previously [1]. We have sampled various peat types along the entire length of the soil column (every 10 cm down to 3 m). Peat samples were analyzed for a wide range of macro- and microelements using an ICP-MS technique following full acid digestion in a microwave oven. These measurements allowed quantitative estimates of major- and trace elements in the peat deposits within the whole bog complex and individual elementary landscapes. Based on the data obtained, the lateral and radial geochemical structures of the bog landscapes were determined and clarified for the first time for middle taiga of the West Siberian plain. The similar regime of mineral nutrition during the complete bog landscape formation was detected for the peat deposits based on the measurements of some major- and trace elements (Ca, Fe, Mg, etc.). The vertical distribution of some major and some trace elements along the profile of peat column is rather uniform with relatively strong increase in the bottom organic layers. This strongly suggests the similarity of the processes of element accumulation in the peat and relatively weak post depositional redistribution of elements within the peat soil profile. Overall, obtained corroborate the existing view on chemical composition of peats being determined by botanical peat's components (which forms this peat deposit), atmospheric precipitation

  1. Particle-induced X-ray emission: thick-target analysis of inorganic materials in the determination of light elements

    International Nuclear Information System (INIS)

    Perez-Arantegui, J.; Castillo, J.R.; Querre, G.

    1994-01-01

    Particle-induced X-ray emission (PIXE) has been applied to the analysis of inorganic materials to determine some elements with Z < 27: Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe, in thick-target analysis. A PIXE method has been developed for the analysis of geological materials, ceramics and pottery. Work has been carried out with an ion beam analytical system, using a low particle beam energy. Relative sensitivity, detection limits, reproducibility and accuracy of the method were calculated based on the analysis of geological standard materials (river sediments, argillaceous limestone, basalt, diorite and granite). Analysis using PIXE offers a number of advantages, such as short analysis time, multi-elemental and nondestructive determinations, and the results are similar to those obtained with other instrumental techniques of analysis. (Author)

  2. 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)

  3. Nuclear reactor fuel element

    International Nuclear Information System (INIS)

    D'Eye, R.W.M.; Shennan, J.V.; Ford, L.H.

    1977-01-01

    Fuel element with particles from ceramic fissionable material (e.g. uranium carbide), each one being coated with pyrolitically deposited carbon and all of them being connected at their points of contact by means of an individual crossbar. The crossbar consists of silicon carbide produced by reaction of silicon metal powder with the carbon under the influence of heat. Previously the silicon metal powder together with the particles was kneaded in a solvent and a binder (e.g. epoxy resin in methyl ethyl ketone plus setting agent) to from a pulp. The reaction temperature lies at 1750 0 C. The reaction itself may take place in a nitrogen atmosphere. There will be produced a fuel element with a high overall thermal conductivity. (DG) [de

  4. Failure phenomena in fibre-reinforced composites. Part 6: a finite element study of stress concentrations in unidirectional carbon fibre-reinforced epoxy composites

    NARCIS (Netherlands)

    van den Heuvel, P.W.J.; Goutianos, S.; Young, R.J.; Peijs, A.A.J.M.

    2004-01-01

    A three-dimensional (3-D) finite element (FE) analysis of the stress situation around a fibre break in a unidirectional carbon fibre-reinforced epoxy composite has been performed. Two cases were considered: (i) good fibre/matrix adhesion and (ii) fibre/matrix debonding. In the case of good adhesion,

  5. 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.

  6. Combustion characteristics of water-insoluble elemental and organic carbon in size selected ambient aerosol particles

    Directory of Open Access Journals (Sweden)

    K. Wittmaack

    2005-01-01

    Full Text Available Combustion of elemental carbon (EC and organic carbon (OC contained in ambient aerosol matter was explored using scanning electron microscopy (SEM in combination with energy dispersive X-ray analysis (EDX. To ease identification of the particles of interest and to avoid or at least reduce interaction with simultaneously sampled inorganic oxides and salts, the approach used in this work differed in two ways from commonly applied procedures. First, rather than using a mixture of particles of vastly different sizes, as in PM10 or PM2.5, aerosol matter was collected in a 5-stage impactor. Second, the water soluble fraction of the collected matter was removed prior to analysis. Diesel soot particles, which appeared in the well-known form of chain-type aggregates, constituted the major fraction of EC. In contrast, OC containing particles were observed in a variety of shapes, including a sizable amount of bioaerosol matter appearing mostly in the size range above about 1 µm. During heating in ambient air for 1h, diesel soot particles were found to be stable up to 470°C, but complete combustion occurred in a narrow temperature interval between about 480 and 510°C. After diesel soot combustion, minute quantities of 'ash' were observed in the form of aggregated tiny particles with sizes less than 10 nm. These particles could be due to elemental or oxidic contaminants of diesel soot. Combustion of OC was observed over a wide range of temperatures, from well below 200°C to at least 500°C. Incompletely burnt bioaerosol matter was still found after heating to 600°C. The results imply that the EC fraction in aerosol matter can be overestimated significantly if the contribution of OC to a thermogram is not well separated.

  7. 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

  8. Elemental diffusion in stars

    International Nuclear Information System (INIS)

    Michaud, Georges; Montmerle, Thierry

    1977-01-01

    This paper is dealing with the origin of the elements in the universe. The scheme of nucleosynthesis is kept to explain the stellar generation of helium, carbon, etc... from the initial hydrogen; but a nonlinear theory is then elaborated to account for the anomalous abundances which were observed. The chemical elements would diffuse throughout the outer layers of a star under the action of the opposite forces of gravitation and radiation. This theory, with completing the nucleosynthesis, would contribute to give a consistent scheme of the elemental origin and abundances [fr

  9. 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

  10. Calculation of phonon dispersion in carbon nanotubes using a continuum-atomistic finite element approach

    Directory of Open Access Journals (Sweden)

    Michael J. Leamy

    2011-12-01

    Full Text Available Dispersion calculations are presented for cylindrical carbon nanotubes using a manifold-based continuum-atomistic finite element formulation combined with Bloch analysis. The formulated finite elements allow any (n,m chiral nanotube, or mixed tubes formed by periodically-repeating heterojunctions, to be examined quickly and accurately using only three input parameters (radius, chiral angle, and unit cell length and a trivial structured mesh, thus avoiding the tedious geometry generation and energy minimization tasks associated with ab initio and lattice dynamics-based techniques. A critical assessment of the technique is pursued to determine the validity range of the resulting dispersion calculations, and to identify any dispersion anomalies. Two small anomalies in the dispersion curves are documented, which can be easily identified and therefore rectified. They include difficulty in achieving a zero energy point for the acoustic twisting phonon, and a branch veering in nanotubes with nonzero chiral angle. The twisting mode quickly restores its correct group velocity as wavenumber increases, while the branch veering is associated with a rapid exchange of eigenvectors at the veering point, which also lessens its impact. By taking into account the two noted anomalies, accurate predictions of acoustic and low-frequency optical branches can be achieved out to the midpoint of the first Brillouin zone.

  11. 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

  12. Preparation of tantalum targets of known thicknesses

    International Nuclear Information System (INIS)

    Alexander, J.R.; Wirth, H.L.

    1985-01-01

    A series of carbon-backed tantalum targets were produced in a heavy ion sputtering system with a Penning ion source. The target thicknesses were then measured using the alpha-ray energy loss method. The resulting tabulated measurements were reproducible and make possible the production of carbon-backed tantalum targets with pre-determined thicknesses ranging from 20 μg/cm 2 to 1 mg/cm 2 . (orig.)

  13. Finite element modeling of nanotube structures linear and non-linear models

    CERN Document Server

    Awang, Mokhtar; Muhammad, Ibrahim Dauda

    2016-01-01

    This book presents a new approach to modeling carbon structures such as graphene and carbon nanotubes using finite element methods, and addresses the latest advances in numerical studies for these materials. Based on the available findings, the book develops an effective finite element approach for modeling the structure and the deformation of grapheme-based materials. Further, modeling processing for single-walled and multi-walled carbon nanotubes is demonstrated in detail.

  14. Spatially-resolved isotopic study of carbon trapped in ∼3.43 Ga Strelley Pool Formation stromatolites

    Science.gov (United States)

    Flannery, David T.; Allwood, Abigail C.; Summons, Roger E.; Williford, Kenneth H.; Abbey, William; Matys, Emily D.; Ferralis, Nicola

    2018-02-01

    The large isotopic fractionation of carbon associated with enzymatic carbon assimilation allows evidence for life's antiquity, and potentially the early operation of several extant metabolic pathways, to be derived from the stable carbon isotope record of sedimentary rocks. Earth's organic carbon isotope record extends to the Late Eoarchean-Early Paleoarchean: the age of the oldest known sedimentary rocks. However, complementary inorganic carbon reservoirs are poorly represented in the oldest units, and commonly reported bulk organic carbon isotope measurements do not capture the micro-scale isotopic heterogeneities that are increasingly reported from younger rocks. Here, we investigated the isotopic composition of the oldest paired occurrences of sedimentary carbonate and organic matter, which are preserved as dolomite and kerogen within textural biosignatures of the ∼3.43 Ga Strelley Pool Formation. We targeted least-altered carbonate phases in situ using microsampling techniques guided by non-destructive elemental mapping. Organic carbon isotope values were measured by spatially-resolved bulk analyses, and in situ using secondary ion mass spectrometry to target microscale domains of organic material trapped within inorganic carbon matrixes. Total observed fractionation of 13C ranges from -29 to -45‰. Our data are consistent with studies of younger Archean rocks that host biogenic stromatolites and organic-inorganic carbon pairs showing greater fractionation than expected for Rubisco fixation alone. We conclude that organic matter was fixed and/or remobilized by at least one metabolism in addition to the CBB cycle, possibly by the Wood-Ljungdahl pathway or methanogenesis-methanotrophy, in a shallow-water marine environment during the Paleoarchean.

  15. Blast response of curved carbon/epoxy composite panels: Experimental study and finite-element analysis

    International Nuclear Information System (INIS)

    Phadnis, V A; Roy, A; Silberschmidt, V V; Kumar, P; Shukla, A

    2013-01-01

    Experimental and numerical studies were conducted to understand the effect of plate curvature on blast response of carbon/epoxy composite panels. A shock-tube system was utilized to impart controlled shock loading to quasi-isotropic composite panels with differing range of radii of curvatures. A 3D Digital Image Correlation (DIC) technique coupled with high-speed photography was used to obtain out-of-plane deflection and velocity, as well as in-plane strain on the back face of the panels. Macroscopic post-mortem analysis was performed to compare yielding and deformation in these panels. A dynamic computational simulation that integrates fluid-structure interaction was conducted to evaluate the panel response in general purpose finite-element software ABAQUS/Explicit. The obtained numerical results were compared to the experimental data and showed a good correlation

  16. The cis decoy against the estrogen response element suppresses breast cancer cells via target disrupting c-fos not mitogen-activated protein kinase activity.

    Science.gov (United States)

    Wang, Li Hua; Yang, Xiao Yi; Zhang, Xiaohu; Mihalic, Kelly; Xiao, Weihua; Farrar, William L

    2003-05-01

    Breast cancer, the most common malignancy in women, has been demonstrated to be associated with the steroid hormone estrogen and its receptor (ER), a ligand-activated transcription factor. Therefore, we developed a phosphorothiolate cis-element decoy against the estrogen response element (ERE decoy) to target disruption of ER DNA binding and transcriptional activity. Here, we showed that the ERE decoy potently ablated the 17beta-estrogen-inducible cell proliferation and induced apoptosis of human breast carcinoma cells by functionally affecting expression of c-fos gene and AP-1 luciferase gene reporter activity. Specificity of the decoy was demonstrated by its ability to directly block ER binding to a cis-element probe and transactivation. Moreover, the decoy failed to inhibit ER-mediated mitogen-activated protein kinase signaling pathways and cell growth of ER-negative breast cancer cells. Taken together, these data suggest that estrogen-mediated cell growth of breast cancer cells can be preferentially restricted via targeted disruption of ER at the level of DNA binding by a novel and specific decoy strategy applied to steroid nuclear receptors.

  17. Multi-Target Angle Tracking Algorithm for Bistatic Multiple-Input Multiple-Output (MIMO Radar Based on the Elements of the Covariance Matrix

    Directory of Open Access Journals (Sweden)

    Zhengyan Zhang

    2018-03-01

    Full Text Available In this paper, we consider the problem of tracking the direction of arrivals (DOA and the direction of departure (DOD of multiple targets for bistatic multiple-input multiple-output (MIMO radar. A high-precision tracking algorithm for target angle is proposed. First, the linear relationship between the covariance matrix difference and the angle difference of the adjacent moment was obtained through three approximate relations. Then, the proposed algorithm obtained the relationship between the elements in the covariance matrix difference. On this basis, the performance of the algorithm was improved by averaging the covariance matrix element. Finally, the least square method was used to estimate the DOD and DOA. The algorithm realized the automatic correlation of the angle and provided better performance when compared with the adaptive asymmetric joint diagonalization (AAJD algorithm. The simulation results demonstrated the effectiveness of the proposed algorithm. The algorithm provides the technical support for the practical application of MIMO radar.

  18. Multi-Target Angle Tracking Algorithm for Bistatic Multiple-Input Multiple-Output (MIMO) Radar Based on the Elements of the Covariance Matrix.

    Science.gov (United States)

    Zhang, Zhengyan; Zhang, Jianyun; Zhou, Qingsong; Li, Xiaobo

    2018-03-07

    In this paper, we consider the problem of tracking the direction of arrivals (DOA) and the direction of departure (DOD) of multiple targets for bistatic multiple-input multiple-output (MIMO) radar. A high-precision tracking algorithm for target angle is proposed. First, the linear relationship between the covariance matrix difference and the angle difference of the adjacent moment was obtained through three approximate relations. Then, the proposed algorithm obtained the relationship between the elements in the covariance matrix difference. On this basis, the performance of the algorithm was improved by averaging the covariance matrix element. Finally, the least square method was used to estimate the DOD and DOA. The algorithm realized the automatic correlation of the angle and provided better performance when compared with the adaptive asymmetric joint diagonalization (AAJD) algorithm. The simulation results demonstrated the effectiveness of the proposed algorithm. The algorithm provides the technical support for the practical application of MIMO radar.

  19. Chemical analysis of carbonates and carbonate rocks by atomic absorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tardon, S

    1981-01-01

    Evaluates methods of determining chemical composition of rocks surrounding black coal seams. Carbonate rock samples were collected in the Ostrava-Karvina coal mines. Sampling methods are described. Determination of the following elements and compounds in carbonate rocks is discussed: calcium, magnesium, iron, manganese, barium, silicon, aluminium, titanium, sodium, potassium, sulfur trioxide, phosphorus pentoxide, water and carbon dioxide. Proportion of compounds insoluble in water in the investigated rocks is also determined. Most of the elements are determined by means of atomic absorption analysis. Phosphorus is also determined by atomic absorption analysis. Other compounds are determined gravimetrically. The described procedure permits weight of a rock sample to be reduced to 0.5 g without reducing analysis accuracy. The results of determining carbonate rock components by X-ray analysis and by chemical analysis are compared. Equipment used for atomic absorption analysis is characterized (the 503 Perkin-Elmer and the CF-4 Optica-Milano spectrophotometers). The analyzed method for determining carbonate rock permits more accurate classification of rocks surrounding coal seams and rock impurities in run-of-mine coal. (22 refs.) (In Czech)

  20. 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

  1. Numerical Modeling and Experimental Study of Elastic-Plastic Behavior of Carbon Nanotubes Reinforced Nanocompsites of PA6/NBR Using a Microfinite Element Model

    Directory of Open Access Journals (Sweden)

    Mir Hamid Reza Ghoreishy

    2014-12-01

    Full Text Available A theoretical and experimental study was conducted on the mechanical behavior of nanocomposites based on PA6/NBR thermoplastic elastomer reinforced by single wall carbon nanotubes (SWNTs. The selected samples include 60 and 40% NBR with 0.5, 1.0 and 1.5% SWNT. The modeling methodology was based on the use of two-dimensional "representative volume elements" (RVE. The Abaqus/standard code was employed to carry out the non-linear finite element calculations. Plane stress elements were selected for discretization of the domain. Linear elastic and isotropic hardening elastic-plastic models were utilized to describe the mechanical behaviors of the carbon nanotubes and polymer matrix, respectively. The samples were simultaneously prepared using melt mixing method in a laboratory internal mixer. Different orientations including regular in both longitudinal and transverse directions and random were selected for the nanotubes in the matrix. Also, two structural forms including hollow and solid for the carbon nanotubes were chosen. The highest and lowest predicted moduli were obtained from models with regular orientation in longitudinal and transverse directions, respectively. On the other hand, comparison between the predicted elastic modulus and elastic-plastic behaviors of the samples with their corresponding experimental data revealed that the random orientation in conjunction with hollow structural form gives the best results. Moreover, the selected material model for the thermoplastic elastomer i.e., isotropic hardening can precisely describe the mechanical behavior in both tension and compression modes. It is also concluded that the main source of error in this modeling methodology can be attributed to the effects of interface between polymer and nanotubes and orientation in perpendicular directions.

  2. DNA demethylases target promoter transposable elements to positively regulate stress responsive genes in Arabidopsis.

    Science.gov (United States)

    Le, Tuan-Ngoc; Schumann, Ulrike; Smith, Neil A; Tiwari, Sameer; Au, Phil Chi Khang; Zhu, Qian-Hao; Taylor, Jennifer M; Kazan, Kemal; Llewellyn, Danny J; Zhang, Ren; Dennis, Elizabeth S; Wang, Ming-Bo

    2014-09-17

    DNA demethylases regulate DNA methylation levels in eukaryotes. Arabidopsis encodes four DNA demethylases, DEMETER (DME), REPRESSOR OF SILENCING 1 (ROS1), DEMETER-LIKE 2 (DML2), and DML3. While DME is involved in maternal specific gene expression during seed development, the biological function of the remaining DNA demethylases remains unclear. We show that ROS1, DML2, and DML3 play a role in fungal disease resistance in Arabidopsis. A triple DNA demethylase mutant, rdd (ros1 dml2 dml3), shows increased susceptibility to the fungal pathogen Fusarium oxysporum. We identify 348 genes differentially expressed in rdd relative to wild type, and a significant proportion of these genes are downregulated in rdd and have functions in stress response, suggesting that DNA demethylases maintain or positively regulate the expression of stress response genes required for F. oxysporum resistance. The rdd-downregulated stress response genes are enriched for short transposable element sequences in their promoters. Many of these transposable elements and their surrounding sequences show localized DNA methylation changes in rdd, and a general reduction in CHH methylation, suggesting that RNA-directed DNA methylation (RdDM), responsible for CHH methylation, may participate in DNA demethylase-mediated regulation of stress response genes. Many of the rdd-downregulated stress response genes are downregulated in the RdDM mutants nrpd1 and nrpe1, and the RdDM mutants nrpe1 and ago4 show enhanced susceptibility to F. oxysporum infection. Our results suggest that a primary function of DNA demethylases in plants is to regulate the expression of stress response genes by targeting promoter transposable element sequences.

  3. Carbon/PEEK composite materials as an alternative for stainless steel/titanium hip prosthesis: a finite element study.

    Science.gov (United States)

    Rezaei, Farshid; Hassani, Kamran; Solhjoei, Nosratollah; Karimi, Alireza

    2015-12-01

    Total hip replacement (THR) has been ranked within the most typical surgical processes in the world. The durability of the prosthesis and loosening of prosthesis are the main concerns that mostly reported after THR surgeries. In THR, the femoral prosthesis can be fixed by either cement or cementless methods in the patient's bones. In both procedures, the stability of the prosthesis in the hosted bone has a key asset in its long-term durability and performance. This study aimed to execute a comparative finite element simulation to assess the load transfer between the prosthesis, which is made of carbon/PEEK composite and stainless steel/titanium, and the femur bone. The mechanical behavior of the cortical bone was assumed as a linear transverse isotropic while the spongy bone was modeled like a linear isotropic material. The implants were made of stainless steel (316L) and titanium alloy as they are common materials for implants. The results showed that the carbon/PEEK composites provide a flatter load transfer from the upper body to the leg compared to the stainless steel/titanium prosthesis. Furthermore, the results showed that the von Mises stress, principal stress, and the strain in the carbon/PEEK composites prosthesis were significantly lower than that made of the stainless steel/titanium. The results also imply that the carbon/PEEK composites can be applied to introduce a new optimum design for femoral prosthesis with adjustable stiffness, which can decrease the stress shielding and interface stress. These findings will help clinicians and biomedical experts to increase their knowledge about the hip replacement.

  4. Carbon deflagration supernova, an alternative to carbon detonation

    Energy Technology Data Exchange (ETDEWEB)

    Nomoto, K; Sugimoto, D [Tokyo Univ. (Japan). Coll. of General Education; Neo, S [Kyoto Univ. (Japan). Dept. of Physics

    1976-02-01

    As an alternative to the carbon detonation, a carbon deflagration supernova model is presented by a full hydrodynamic computation. A deflagration wave, which propagates through the core due to convective heat transport, does not grow into detonation. Though it results in a complete disruption of the star, the difficulty of overproduction of iron peak elements can be avoided if the deflagration is relatively slow.

  5. Impact of trace element additives on anaerobic digestion of sewage sludge with in-situ carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Linville, Jessica L.; Shen, Yanwen; Schoene, Robin P.; Nguyen, Maximilian; Urgun-Demirtas, Meltem; Snyder, Seth W.

    2016-09-01

    Anaerobic digestion (AD) of sludge at wastewater treatment plants can benefit from addition of essential trace metals such as iron, nickel and cobalt to increase biogas production for utilization in combined heat and power systems, fed into natural gas pipelines or as a vehicle fuel. This study evaluated the impact and benefits of Ni/Co and olivine addition to the digester at mesophilic temperatures. These additions supplement previously reported research in which iron-rich olivine (MgSiO4) was added to sequester CO2 in-situ during batch AD of sludge. Trace element addition has been shown to stimulate and stabilize biogas production and have a synergistic effect on the mineral carbonation process. AD with 5% w/v olivine and 1.5 mg/L Ni/Co addition had a 17.3% increase in methane volume, a 6% increase in initial exponential methane production rate and a 56% increase in methane yield (mL CH4/g CODdegraded) compared to the control due to synergistic trace element and olivine addition while maintaining 17.7% CO2 sequestration from olivine addition. Both first-order kinetic modeling and response surface methodology modeling confirmed the combined benefit of the trace elements and olivine addition. These results were significantly higher than previously reported results with olivine addition alone [1].

  6. 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

  7. Is it wise to protect false targets?

    International Nuclear Information System (INIS)

    Levitin, Gregory; Hausken, Kjell

    2011-01-01

    The paper considers a system consisting of genuine elements and false targets that cannot be distinguished by the attacker's observation. The false targets can be destroyed with much less effort than the genuine elements. We show that even when an attacker cannot distinguish between the genuine elements and the false targets, in many cases it can enhance the attack efficiency using a double attack strategy in which it tries first to eliminate with minimal effort as many false targets as possible in the first attack and then distributes its entire remaining resource among all surviving targets in the second attack. The model for evaluating the system vulnerability in the double attack is suggested for a single genuine element, and multiple genuine elements configured in parallel or in series. This model assumes that in both attacks the attacking resource is distributed evenly among the attacked targets. The defender can optimize its limited resource distribution between deploying more false targets and protecting them better. The attacker can optimize its limited resource distribution between two attacks. The defense strategy is analyzed based on a two period minmax game. A numerical procedure is suggested that allows the defender to find the optimal resource distribution between deploying and protecting the false targets. The methodology of optimal attack and defense strategies analysis is demonstrated. It is shown that protecting the false targets may reduce the efficiency of the double attack strategy and make this strategy ineffective in situations with low contest intensity and few false targets. - Highlights: ► The efficiency of the double attack tactics against using false targets is analyzed. ► The role of the false target protection in system survivability enhancement is shown. ► The resource distribution between deploying more false targets and protecting them better is optimized. ► Both series and parallel systems are considered.

  8. 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.

  9. Photo-neutron yields from thin and thick targets irradiated by 2.0 GeV electrons

    International Nuclear Information System (INIS)

    Hee-Seock, Lee; Syuichi, Ban; Toshiya, Sanami; Kazutoshi, Takahashi; Tatsuhiko, Sato; Kazuo, Shin

    2005-01-01

    The photo-neutron yields from thin and thick targets irradiated by high energy electrons were studied. The photo-neutron spectra at 90 deg C relative to the incident 2.0 GeV electrons were measured by the pulsed beam time-of-flight technique using the Pilot-U plastic scintillator and the NE213 liquid scintillator with 2 inches in length and 2 inches in diameter. Targets, from low-Z element (carbon) to high-Z element (bismuth) and with thin (0.5 Xo) and thick (10 Xo) thickness, were used in this study. The differential photo-neutron yields between 2 MeV (mainly 8 MeV) and 400 MeV were obtained. The systematics was studied to make empirical yield terms for shielding application. Recently, the study of the angular distributed yields was conducted at two other observing angles, 48 deg C and 140 deg C. The photo-neutron yields between 8 MeV and 250 MeV were obtained for thick targets. The experimental data were compared with results calculated using the EGS4+PICA3 or the MCNPX 2.5d code. (authors)

  10. 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.

  11. 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.

  12. Histological and elemental changes in the rat brain after local irradiation with carbon ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Sentaro; Sun, Xue-Zhi; Kubota, Yoshihisa; Takai, Nobuhiko; Nojima, Kumie [National Inst. of Radiological Sciences, Chiba (Japan)

    2002-06-01

    The left cerebral hemispheres of adult Sprague-Dawley rat brains were irradiated at doses of 30, 50, or 100 Gy with charged carbon particles (290 MeV/nucleon; 5 mm spread-out Bragg peak). The spread-out Bragg peak used here successfully and satisfactorily retained its high-dose localization in the defined region. A histological examination showed that necrotic tissue damage, hemorrhage in the thalamus, and vasodilatations around the necrotic region were induced at 8 weeks after 100 Gy irradiation. The regions with tissue damage correlated well with those expected from the radiation-dose distribution, indicating an advantage of charged carbon particles for irradiating restricted brain regions. An X-ray fluorescent analysis demonstrated a decrease in the concentrations of K and P, and an increase in the concentrations of Cl, Fe, Zn in the damaged region at 8 weeks post-irradiation, though no significant changes were observed before 4 weeks of post-irradiation. This may indicate that even the very high radiation doses used here did not induce acute and immediate neuronal cell death, in contrast with ischemic brain injury where acute neuronal cell death occurred and the elemental concentrations changed within a day after the induction of ischemia. (author)

  13. Four Years of Highly Time Resolved Measurements of Elemental and Organic Carbon at a Rural Background Site in Central Europe.

    Czech Academy of Sciences Publication Activity Database

    Mbengue, S.; Fusek, M.; Schwarz, Jaroslav; Vodička, Petr; Holubová Šmejkalová, Adéla; Holoubek, I.

    2018-01-01

    Roč. 182, June 2018 (2018), s. 335-346 ISSN 1352-2310 R&D Projects: GA MŠk(CZ) LM2015037; GA MŠk(CZ) EF16_013/0001315 EU Projects: European Commission(XE) 654109 - ACTRIS-2 Institutional support: RVO:67985858 Keywords : elemental - organic carbon * OC/EC ratio * rural background site * air masses origin * censored data * variability OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 3.629, year: 2016

  14. Source contributions to atmospheric fine carbon particle concentrations

    Science.gov (United States)

    Andrew Gray, H.; Cass, Glen R.

    A Lagrangian particle-in-cell air quality model has been developed that facilitates the study of source contributions to atmospheric fine elemental carbon and fine primary total carbon particle concentrations. Model performance was tested using spatially and temporally resolved emissions and air quality data gathered for this purpose in the Los Angeles area for the year 1982. It was shown that black elemental carbon (EC) particle concentrations in that city were dominated by emissions from diesel engines including both on-highway and off-highway applications. Fine primary total carbon particle concentrations (TC=EC+organic carbon) resulted from the accumulation of small increments from a great variety of emission source types including both gasoline and diesel powered highway vehicles, stationary source fuel oil and gas combustion, industrial processes, paved road dust, fireplaces, cigarettes and food cooking (e.g. charbroilers). Strategies for black elemental carbon particle concentration control will of necessity need to focus on diesel engines, while controls directed at total carbon particle concentrations will have to be diversified over a great many source types.

  15. Optimization of in-target yields for RIB production: Part 1: direct targets

    International Nuclear Information System (INIS)

    Chabod, S.; Thiolliere, N.; David, J.Ch.; Dore, D.; Ene, D.; Rapp, B.; Ridikas, D.; Chabod, S.; Blideanu, V.

    2008-03-01

    In the framework of the EURISOL-DS project and within Task-11, we have performed in-target yield calculations for different configurations of thick direct targets. The target materials tested are Al 2 O 3 , SiC, Pb(molten), Ta and UC 3 . The target was irradiated with protons of 0.5, 1.0, 1.5 and 2.0 GeV. The production rates have been computed using the MCNPX transport/generation code, coupled with the CINDER-90 evolution program. The yield distributions as a function of charge number Z and mass number A have been evaluated. Their production rates have been optimized for 11 selected elements (Li, Be, Ne, Mg, Ar, Ni, Ga, Kr, Hg, Sn and Fr) and 23 of their isotopes of interest. Finally, the isotopic distributions for each of these 11 elements have been optimized in terms of the target material, its geometry, and incident proton energy

  16. Acceptance criteria for the ITER divertor vertical target

    International Nuclear Information System (INIS)

    Fouquet, S.; Schlosser, J.; Merola, M.; Durocher, A.; Escourbiac, F.; Grosman, A.; Missirlian, M.; Portafaix, C.

    2006-01-01

    In the frame of the toroidal pump limiter fabrication for Tore Supra, CEA developed a large experience of infrared test for acceptance of high heat flux components armoured with carbon fibre composite flat tiles. The test is based on a thermal transient induced by an alternative hot/cold water flow in the heat sink structure. The tile surface temperature transients are compared with those of a reference element, the maximum difference for each tile leading to a value called ΔT ref m ax . This method is proposed for the commissioning of plasma facing components for the ITER divertor vertical target. This paper describes the determination of the best acceptance criteria for the 'monoblock' geometry of the carbon part. First, it has been shown that the location and the extension of the defects could reliably be determined by monitoring both top and lateral surfaces during the test. Second, it was possible to fix an acceptance method based on ΔT ref m ax . Samples with calibrated defects are now under fabrication to validate the results

  17. Mobility of organic carbon from incineration residues

    International Nuclear Information System (INIS)

    Ecke, Holger; Svensson, Malin

    2008-01-01

    Dissolved organic carbon (DOC) may affect the transport of pollutants from incineration residues when landfilled or used in geotechnical construction. The leaching of dissolved organic carbon (DOC) from municipal solid waste incineration (MSWI) bottom ash and air pollution control residue (APC) from the incineration of waste wood was investigated. Factors affecting the mobility of DOC were studied in a reduced 2 6-1 experimental design. Controlled factors were treatment with ultrasonic radiation, full carbonation (addition of CO 2 until the pH was stable for 2.5 h), liquid-to-solid (L/S) ratio, pH, leaching temperature and time. Full carbonation, pH and the L/S ratio were the main factors controlling the mobility of DOC in the bottom ash. Approximately 60 weight-% of the total organic carbon (TOC) in the bottom ash was available for leaching in aqueous solutions. The L/S ratio and pH mainly controlled the mobilization of DOC from the APC residue. About 93 weight-% of TOC in the APC residue was, however, not mobilized at all, which might be due to a high content of elemental carbon. Using the European standard EN 13 137 for determination of total organic carbon (TOC) in MSWI residues is inappropriate. The results might be biased due to elemental carbon. It is recommended to develop a TOC method distinguishing between organic and elemental carbon

  18. 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

  19. Contribution to the simultaneous determination of several light elements in alkalin metals by gamma photon and charged particle activation. Application to carbon and nitrogen determination in sodium

    International Nuclear Information System (INIS)

    Bock, Patrice.

    1976-10-01

    A new γ activation method for the simultaneous determination of carbon and nitrogen in sodium is described. It makes use of the nuclear reactions: 12 C(γ,n) 11 C and 14 N(γ,n) 13 N. The process used to separate carbone-11 and nitrogen-13 from sodium with a view to their radio-activity determination is based on vacuum dissolution of the sample in a mixture of oxidizing and acid fused salts. The oxidized carbon is trapped as CO 2 on soda asbestos and the nitrogen as N 2 on molecular sieve at -196 deg C. The efficiency of the technique is estimated by means of tracer tests and by proton activation. The relative influence of competitive nuclear reactions on elements close to the above two impurities, or even on the matrix itself, is examined. The method described has a theoretical detection limit of some 10 -8 g.g -1 for the two elements in question and mean concentrations of 0.3+-0.1x10 -6 g.g -1 carbon and 1.0+-0.5x10 -6 g.g -1 nitrogen have in fact been measured in a batch of 0.5 g sodium samples [fr

  20. A Large-scale Finite Element Model on Micromechanical Damage and Failure of Carbon Fiber/Epoxy Composites Including Thermal Residual Stress

    Science.gov (United States)

    Liu, P. F.; Li, X. K.

    2018-06-01

    The purpose of this paper is to study micromechanical progressive failure properties of carbon fiber/epoxy composites with thermal residual stress by finite element analysis (FEA). Composite microstructures with hexagonal fiber distribution are used for the representative volume element (RVE), where an initial fiber breakage is assumed. Fiber breakage with random fiber strength is predicted using Monte Carlo simulation, progressive matrix damage is predicted by proposing a continuum damage mechanics model and interface failure is simulated using Xu and Needleman's cohesive model. Temperature dependent thermal expansion coefficients for epoxy matrix are used. FEA by developing numerical codes using ANSYS finite element software is divided into two steps: 1. Thermal residual stresses due to mismatch between fiber and matrix are calculated; 2. Longitudinal tensile load is further exerted on the RVE to perform progressive failure analysis of carbon fiber/epoxy composites. Numerical convergence is solved by introducing the viscous damping effect properly. The extended Mori-Tanaka method that considers interface debonding is used to get homogenized mechanical responses of composites. Three main results by FEA are obtained: 1. the real-time matrix cracking, fiber breakage and interface debonding with increasing tensile strain is simulated. 2. the stress concentration coefficients on neighbouring fibers near the initial broken fiber and the axial fiber stress distribution along the broken fiber are predicted, compared with the results using the global and local load-sharing models based on the shear-lag theory. 3. the tensile strength of composite by FEA is compared with those by the shear-lag theory and experiments. Finally, the tensile stress-strain curve of composites by FEA is applied to the progressive failure analysis of composite pressure vessel.

  1. Use of activated carbon adsorption in conjunction with radiation treatment processes

    International Nuclear Information System (INIS)

    Dickson, L.W.; Lopata, V.J.; Toft-Hall, A.; Kremers, W.; Singh, A.

    1988-01-01

    This report presents the results of an assessment of the potential applications of combined adsorption-irradiation treatment processes. The rationale for the study was to determine whether the cost of radiation treatment could be reduced by concentrating target species on an adsorbent in the radiation field. Several different studies on adsorption-irradiation treatment were identified in the literature, and experimental work was done on both the conversion of sulphur dioxide to elemental sulphur, and the removal of trihalomethanes from water by adsorption on activated carbon and subsequent irradiation. Adsorption-irradiation treatment would appear to be less costly than irradiation alone for radiolytic decomposition of target species at low concentration in liquid streams, in the presence of high-surface-area, electrically insulating adsorbents. 116 refs

  2. [In vivo evaluation of carbon fiber posts].

    Science.gov (United States)

    Lai, V; Lugliè, P F; Chessa, G

    2002-05-01

    The use of carbon fiber posts allows morpho-functional restoration of endodontically treated teeth with an assembly of materials of a modulus of elasticity similar to that of dentin. The study clinically evaluated the percentage of survival of dental elements treated and reconstructed with endocanal carbon fiber posts. At the Dentistry Clinic of the University of Sassari 60 dental elements were selected from 46 subjects. The teeth, which had been treated endodontically with success for at least six months, were classified by parameters taken from the international literature and reconstructed using Tech 2000 carbon fiber posts and adhesive resinous systems recommended by the post manufacturer. The success rate was 98.4%. Almost half (49%) of the samples were single-rooted elements, 37.4% of the posts were 1.2 mm in diameter; in 78.3% the opposing contact was with a natural tooth; 100% of the elements had a type A dental structure. Third generation posts are a valid alternative to metallic posts and improve the prognosis of the treated element. The carbon fiber posts fixed with the composite, forming a single unit with the dental element, thus improving mid-term RESULTS. The technique is easy to use under clinical conditions and can be performed in a single session. So far, the method has provided promising clinical results, as this study demonstrated.

  3. Elements of Eoarchean life trapped in mineral inclusions

    DEFF Research Database (Denmark)

    Hassenkam, T.; Andersson, M. P.; Dalby, K. N.

    2017-01-01

    with carbon-rich sedimentary beds in the host rock, where carbon is fully graphitized. Previous studies have not been able to document other elements of life (mainly hydrogen, oxygen, nitrogen and phosphorus) structurally bound to this carbonaceous material. Here we study carbonaceous inclusions armoured...... residues within sedimentary material corroborates earlier claims for the biogenic origins of carbon in Isua metasediments....

  4. Four years of highly time resolved measurements of elemental and organic carbon at a rural background site in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Mbengue, Saliou; Fusek, M.; Schwarz, J.; Vodička, P.; Holubová Šmejkalová, Adéla; Holoubek, Ivan

    2018-01-01

    Roč. 182, jun (2018), s. 335-346 ISSN 1352-2310 R&D Projects: GA MŠk(CZ) LM2015037; GA MŠk(CZ) LO1415; GA MŠk(CZ) EF16_013/0001315 EU Projects: European Commission(XE) 654109 - ACTRIS-2 Institutional support: RVO:67179843 Keywords : Air masses origin * Censored data * Elemental organic carbon * OC/EC ratio * Rural background site * Variability Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 3.629, year: 2016

  5. Development of a preparation system for the radiocarbon analysis of organic carbon in carbonaceous aerosols in China

    International Nuclear Information System (INIS)

    Zhang, Y.L.; Liu, D.; Shen, C.D.; Ding, P.; Zhang, G.

    2010-01-01

    Carbonaceous aerosols comprising a large fraction of elemental carbon (EC) and organic carbon (OC) are considered to affect both global climate and human health. Radiocarbon measurements have been proved to be a useful isotopic tracer for distinguishing contemporary and fossil emissions. An optimized system of a two-step thermal preparation system for radiocarbon ( 14 C) measurement of OC/TC is firstly established in China. In this system, OC/TC are converted into carbon dioxide under a pure oxygen flow at 340 o C/650 o C and then reduced to graphite for AMS target using the method of zinc reduction. Afterwards, radiocarbon measurements of the targets performed by the NEC Compact AMS System at the Institute of Heavy Ion Physics, Peking University. The measured results for estimated reference martial including HOx I, HOx II and IAEA-C6 are consistent with internationally accepted values. The radiocarbon-based source appointment of carbonaceous aerosols in China would be much more convenient and faster with the preparation system developed in this work.

  6. On the properties of nanocomposite amorphous carbon films prepared by off-plane double bend filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    Tay, B.K.; Zhang, P.

    2002-01-01

    It is known to deposit hard thin films, such as tetrahedral amorphous carbon (ta-C), using a filtered cathode vacuum arc (FCVA). These ta-C films have interesting and useful properties because of the high sp 3 fraction of carbon atoms (up to 87%) in the film. However, the high internal stress in the films can limit their applications as the film may flake away from the substrate. In order to reduce the internal stress of the ta-C films and in an attempt to improve adhesion of thick films of this type, growth modifications such as incorporating metal into the ta-C films have been carried out. Nanocomposite amorphous carbon films were deposited by FCVA technique using metal-carbon composite target. Atomic force microscopy, Raman, and X-ray photoelectron spectroscopy were used to characterize the morphology and structure of the films. Nanoindenter and surface profilometer were used to determine the hardness, Young's modulus, and internal stress. The same metal composition targets for different elements results in different metal composition in the corresponding nanocomposite amorphous carbon films. We attribute this observation to the dynamic balance deposition effect of the FCVA deposition process. The influence of the type of metallic elements and its composition in the films on the structural, mechanical properties, surface energy and field emission (FE) performance was studied. The incorporation of metal into the films results in the decrease of sp 3 fraction, internal stress in the films, but the hardness and Young's modulus remains at high level. The surface energy of the films increases with incorporating Ni atoms, but decreases after incorporating Fe and Al atoms into the films. After heat-treatment, the incorporation of metal into ta-C films can greatly improve the FE performance

  7. Radiochemical separations of target-like reaction products from Au-, Pt-, and Th-targets after irradiation with GeV protons

    International Nuclear Information System (INIS)

    Szweryn, B.; Bruechle, W.; Schausten, B.; Schaedel, M.

    1988-08-01

    Chemical separation procedures for separations of reaction products after spallation reactions with 2.6 GeV protons and heavy element targets are presented. To determine independent cross sections of individual isotopes the elements Au, Pt, Ir, Os, Re, W, Ta, Hf, (Lu, Yb, Tm, Er), (Gd, Eu, Sm), were separated from gold targets, Pt, Ir, Os, W, Ta, Hf, (Lu, Yb, Tm, Er), (Gd, Eu, Sm) from a platinum target and Au, Tl from a thorium target. (orig.)

  8. 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.

  9. Porous Carbon Materials for Elements in Low-Temperature Fuel Cells

    Directory of Open Access Journals (Sweden)

    Wlodarczyk R.

    2015-04-01

    Full Text Available The porosity, distribution of pores, shape of pores and specific surface area of carbon materials were investigated. The study of sintered graphite and commercial carbon materials used in low-temperature fuel cells (Graphite Grade FU, Toray Teflon Treated was compared. The study covered measurements of density, microstructural examinations and wettability (contact angle of carbon materials. The main criterion adopted for choosing a particular material for components of fuel cells is their corrosion resistance under operating conditions of hydrogen fuel cells. In order to determine resistance to corrosion in the environment of operation of fuel cells, potentiokinetic curves were registered for synthetic solution 0.1M H2SO4+ 2 ppmF-at 80°C.

  10. Graphite targets at LAMPF

    International Nuclear Information System (INIS)

    Brown, R.D.; Grisham, D.L.

    1983-01-01

    Rotating polycrystalline and stationary pyrolytic graphite target designs for the LAMPF experimental area are described. Examples of finite element calculations of temperatures and stresses are presented. Some results of a metallographic investigation of irradiated pyrolytic graphite target plates are included, together with a brief description of high temperature bearings for the rotating targets

  11. Unburned carbon in combustion residues from mainly solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem H; Lind B; Lagerkvist A

    2012-02-15

    Unburned carbon in 21 combustion residues from solid biofuels is investigated using several methods of analysis (a.o. LOI and TOC), as well as micro-Raman spectroscopy. The results are used to discuss the distribution of unburned carbon in the residues from the different combustion plants and its nature (organic or elemental). The consequences of the elemental nature of carbon for environmental properties of the residue are noted

  12. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  13. 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

  14. ENTERPRISE RESOURCE STRATEGIC PLANNING: TARGET CHOICE TECHNIQUES

    Directory of Open Access Journals (Sweden)

    A. S. Lankin

    2011-01-01

    Full Text Available Choice of the targets is one of most important elements of the resource planning system. Particular feature of the strategic planning is development of future alternatives for the enterprise. Main resource strategic planning cycle elements: examination of principal external and internal environment components; forming the company mission; development of long-term targets; concretization of the long-term targets through short-term aims; examination of strategies and final choice.

  15. Temporal and Spatial variations in Organic and Elemental carbon concentrations in PM10/PM2.5 in the Metropolitan Area of Costa Rica, Central America

    Science.gov (United States)

    Campos-Ramos, A.; Herrera Murillo, J.; Rodriguez-Roman, S.; Cardenas, B.; Blanco-Jimenez, S.

    2011-12-01

    During 2010-2011, as part of a Binational Cooperation Project between Mexico and Costa Rica, samples collected weekly in 15 and 5 sites for PM10 and PM2,5 respectively, in the Metropolitan area of Costa Rica, a region of 2.5 million habitants. Based on the high PM2.5 mass concentrations found (17-38 μg/m3), samples were analyzed to determinate the organic and elemental carbon concentrations using DRI Model 2001 Thermal/Optical Carbon Analyzer (Atmoslytic Inc., Calabasas, CA, USA). Organic (OC) and Elemental (EC) carbon concentrations exhibited a clear seasonal pattern with higher concentrations in the rainy period than in the dry period, due to cooperative effects of changes in emission rates and seasonal meteorology. Spatial variations in carbonaceous species concentrations were observed mostly influenced by the local sources at the different sampling sites in the following magnitude of contribution: vehicle emissions > industrial > agricultural burning. Total carbonaceous aerosol accounted for 42.7% and 26.8% of PM2.5 mass in rainy and dry period, respectively. Good correlation (R = 0.87-0.93) between OC and EC indicated that they had common dominant sources of combustion such as heavy fuels used in industries and traffic emissions. The estimated secondary organic carbon (SOC) accounted for 46.9% and 35.3% of the total OC in the rainy and dry period, respectively, indicating that SOC may be an important contributor to fine organic aerosol in the Metropolitan Area of Costa Rica. These results will be used to improve the National Emissions Inventory, particularly for PM2.5.

  16. Combining charcoal and elemental black carbon analysis in sedimentary archives: Implications for past fire regimes, the pyrogenic carbon cycle, and the human-climate interactions

    Science.gov (United States)

    Thevenon, Florian; Williamson, David; Bard, Edouard; Anselmetti, Flavio S.; Beaufort, Luc; Cachier, Hélène

    2010-07-01

    This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles > 0.2 µm 2 remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after thermal and chemical oxidative treatments is quantified as black carbon (BC). The obtained pyrogenic carbon records from three sediment core-based case studies, (i) the Late Pleistocene equatorial Pacific Ocean, (ii) the mid-Holocene European Lake Lucerne, and (iii) the Late Holocene African Lake Masoko, are interpreted as proxy records of regional transportation mechanisms and biomass burning activities. The results show that the burial of dark carbon-rich particles in the 360 kyr-long record from the west equatorial Pacific is controlled by the combination of sea-level changes and low-latitude atmospheric circulation patterns (summer monsoon dynamics). However, the three fold increases in charcoal and BC sediment influxes between 53-43 and 12-10 kyr BP suggest that major shifts in fire activity occur synchronously with human colonization in the Indo/Pacific region. The coarse charcoal distribution from a 7.2 kyr record from Lake Lucerne in Switzerland closely matches the regional timing of major technical, land-use, and socio-economic changes during the Neolithic (between ca. 5.7 and 5.2 kyr BP and 4.9-4.5 kyr BP), the Bronze and Iron Ages (at ca. 3.3 and 2.4 kyr BP, respectively), and the industrialization (after AD 1838), pointing to the key impact of human activities on the sources, transportation processes and reservoirs of refractory carbon during the Holocene. In the tropical Masoko maar lake in Tanzania, where charcoal and BC records are highly sensitive to the local climate

  17. Distribution, movement, and evolution of the volatile elements in the lunar regolith

    International Nuclear Information System (INIS)

    Gibson, E.K. Jr.

    1975-01-01

    The abundances and distributions of carbon, nitrogen, and sulfur in lunar soils are reviewed. Carbon and nitrogen have a predominantly extra-lunar origin in lunar soils and breccias, while sulfur is mostly indigeneous to the Moon. The lunar processes which effect the movement, distribution, and evolution of carbon, nitrogen, and sulfur, along with the volatile alkali elements sodium, potassium, and rubidium during regolith processes are discussed. Possible mechanisms which may result in the addition to or loss from the Moon of these volatile elements are considered. (Auth.)

  18. Distribution, movement, and evolution of the volatile elements in the lunar regolith

    Science.gov (United States)

    Gibson, E. K., Jr.

    1975-01-01

    The abundances and distributions of carbon, nitrogen, and sulfur in lunar soils are reviewed. Carbon and nitrogen have a predominantly extra-lunar origin in lunar soils and breccias, while sulfur is mostly indigeneous to the moon. The lunar processes which effect the movement, distribution, and evolution of carbon, nitrogen, and sulfur, along with the volatile alkali elements sodium, potassium, and rubidium during regolith processes are discussed. Possible mechanisms which may result in the addition to or loss from the moon of these volatile elements are considered.

  19. Laser ablation for the synthesis of carbon nanotubes

    Science.gov (United States)

    Holloway, Brian C.; Eklund, Peter C.; Smith, Michael W.; Jordan, Kevin C.; Shinn, Michelle

    2010-04-06

    Single walled carbon nanotubes are produced in a novel apparatus by the laser-induced ablation of moving carbon target. The laser used is of high average power and ultra-fast pulsing. According to various preferred embodiments, the laser produces an output above about 50 watts/cm.sup.2 at a repetition rate above about 15 MHz and exhibits a pulse duration below about 10 picoseconds. The carbon, carbon/catalyst target and the laser beam are moved relative to one another and a focused flow of "side pumped", preheated inert gas is introduced near the point of ablation to minimize or eliminate interference by the ablated plume by removal of the plume and introduction of new target area for incidence with the laser beam. When the target is moved relative to the laser beam, rotational or translational movement may be imparted thereto, but rotation of the target is preferred.

  20. Laser ablation for the synthesis of carbon nanotubes

    Science.gov (United States)

    Holloway, Brian C. (Inventor); Eklund, Peter C. (Inventor); Smith, Michael W. (Inventor); Jordan, Kevin C. (Inventor); Shinn, Michelle (Inventor)

    2012-01-01

    Single walled carbon nanotubes are produced in a novel apparatus by the laser-induced ablation of moving carbon target. The laser used is of high average power and ultra-fast pulsing. According to various preferred embodiments, the laser produces and output above about 50 watts/cm.sup.2 at a repetition rate above about 15 MHz and exhibits a pulse duration below about 10 picoseconds. The carbon, carbon/catalyst target and the laser beam are moved relative to one another and a focused flow of "side pumped", preheated inert gas is introduced near the point of ablation to minimize or eliminate interference by the ablated plume by removal of the plume and introduction of new target area for incidence with the laser beam. When the target is moved relative to the laser beam, rotational or translational movement may be imparted thereto, but rotation of the target is preferred.

  1. Preparation of spherical fuel elements for HTR-PM in INET

    International Nuclear Information System (INIS)

    Xiangwen, Zhou; Zhenming, Lu; Jie, Zhang; Bing, Liu; Yanwen, Zou; Chunhe, Tang; Yaping, Tang

    2013-01-01

    Highlights: • Modifications and optimizations in the manufacture of spherical fuel elements (SFE) for HTR-PM are presented. • A newly developed overcoater exhibits good stability and high efficiency in the preparation of overcoated particles. • The optimized carbonization process reduces the process time from 70 h in the period of HTR-10 to 20 h. • Properties of the prepared SFE and matrix graphite balls meet the design specifications for HTR-PM. • In particular the mean free uranium fraction of 5 consecutive batches is only 8.7 × 10 −6 . -- Abstract: The spherical fuel elements were successfully manufactured in the period of HTR-10. In order to satisfy the mass production of fuel elements for HTR-PM, several measures have been taken in modifying and optimizing the manufacture process of fuel elements. The newly developed overcoater system and its corresponding parameters exhibited good stability and high efficiency in the preparation of overcoated particles. The optimized carbonization process could reduce the carbonization time from more than 70 h to 20 h and improve the manufacturing efficiency. Properties of the manufactured spherical fuel elements and matrix graphite balls met the design specifications for HTR-PM. The mean free uranium fraction of 5 consecutive batches was 8.7 × 10 −6 . The optimized fuel elements manufacturing process could meet the requirements of design specifications of spherical fuel elements for HTR-PM

  2. A boundary integral method for numerical computation of radar cross section of 3D targets using hybrid BEM/FEM with edge elements

    Science.gov (United States)

    Dodig, H.

    2017-11-01

    This contribution presents the boundary integral formulation for numerical computation of time-harmonic radar cross section for 3D targets. Method relies on hybrid edge element BEM/FEM to compute near field edge element coefficients that are associated with near electric and magnetic fields at the boundary of the computational domain. Special boundary integral formulation is presented that computes radar cross section directly from these edge element coefficients. Consequently, there is no need for near-to-far field transformation (NTFFT) which is common step in RCS computations. By the end of the paper it is demonstrated that the formulation yields accurate results for canonical models such as spheres, cubes, cones and pyramids. Method has demonstrated accuracy even in the case of dielectrically coated PEC sphere at interior resonance frequency which is common problem for computational electromagnetic codes.

  3. Towards a low carbon growth in Mexico: Is a double dividend possible? A dynamic general equilibrium assessment

    International Nuclear Information System (INIS)

    Landa Rivera, Gissela; Reynès, Frédéric; Islas Cortes, Ivan; Bellocq, François-Xavier; Grazi, Fabio

    2016-01-01

    This paper simulates the medium- and long-term impact of proposed and expected energy policy on the environment and on the Mexican economy. The analysis has been conducted with a Multi-sector Macroeconomic Model for the Evaluation of Environmental and Energy policy (Three-ME). This model is well suited for policy assessment purposes in the context of developing economies as it indicates the transitional effects of policy intervention. Three-ME estimates the carbon tax required to meet emissions reduction targets within the Mexican “Climate Change Law”, and assesses alternative policy scenarios, each reflecting a different strategy for the recycling of tax revenues. With no compensation, the taxation policy would reduce CO_2 emissions by more than 75% by 2050 with respect to Business as Usual (BAU), but at high economic costs. Under full redistribution of carbon tax revenues, a double dividend arises: the policy appears beneficial both in terms of GDP and CO_2 emissions reduction. - Highlights: •A model is designed to evaluate transitional effects of climate policy in Mexico. •The level of the carbon tax is computed to meet national emissions targets in 2050. •Distribution of the carbon tax revenues is a key element to get a double dividend. •Magnitude of benefits depends on the flexibility of production/consumption structure. •A double dividend is possible even when carbon tax is implemented unilaterally.

  4. Simulation of dielectrophoretic assembly of carbon nanotubes using 3D finite element analysis

    International Nuclear Information System (INIS)

    Berger, S D; McGruer, N E; Adams, G G

    2015-01-01

    One of the most important methods for selective and repeatable assembly of carbon nanotubes (CNTs) is alternating current dielectrophoresis (DEP). This method has been demonstrated experimentally as a viable technique for nano-scale manufacturing of novel CNT based devices. Previous numerical analyses have studied the motion of nanotubes, the volume from which they are assembled, and the rate of assembly, but have been restricted by various simplifying assumptions. In this paper we present a method for simulating the motion and behavior of CNTs subjected to dielectrophoresis using a three-dimensional electrostatic finite element analysis. By including the CNT in the finite element model, we can accurately predict the effect of the CNT on the electric field and the resulting force distribution across the CNT can be determined. We have used this information to calculate the motion of CNTs assembling onto the electrodes, and show how they tend to move towards the center of an electrode and come into contact at highly skewed angles. Our analysis suggests that the CNTs move to the electrode gap only after initially contacting the electrodes. We have also developed a model of the elastic deformation of CNTs as they approach the electrodes demonstrating how the induced forces can significantly alter the CNT shape during assembly. These results show that the CNT does not behave as a rigid body when in close proximity to the electrodes. In the future this method can be applied to a variety of real electrode geometries on a case-by-case basis and will provide more detailed insight into the specific motion and assembly parameters necessary for effective DEP assembly. (paper)

  5. Isotopic characterization of targets for nuclear measurements at CBNM

    International Nuclear Information System (INIS)

    Bievre, P. de

    1985-01-01

    Nuclear measurements for which ''nuclear'' targets are prepared are almost always isotope-specific i.e. they are normally related to a particular nuclide in the target. The amount of this nuclide must be accurately assessed. There are essentially two ways to determine the number of atoms of this particular nuclide. (1) By determination of the amount of element, to which the nuclide belongs, on the target via classsical means; weighing substraction of impurities, calculation of element amount using known of the chemical compound in which the element is incorporated and, finally, measurement of the isotopic composition in order to determine the fraction of the nuclide concerned in the element. An alternative way may be to perform an elemental assay on the target followed by determination of the isotopic composition. (2) Another approach is isotope dilution mass spectrometry where a change in the isotopic composition of the ''target'' is induced by adding a known number of atoms (called ''spike'') of the element with a quite different composition. Measurement of the resulting change in isotopic composition yields directly the number of atoms of the nuclide under investigation. The method is highly selective, accurate and isotope-specific. (orig.)

  6. Effect of halide impregnation on elemental mercury removal of activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Yim, Yoon Ji; Park, Soo Jin [Dept. of Chemistry, Inha University, Incheon (Korea, Republic of)

    2017-02-15

    Activated carbons (ACs) were impregnated with potassium halides (KX) to enhance the removal efficiency of elemental mercury (Hg{sup 0}). In this work, the impregnation effect of potassium bromide (KBr) and potassium iodine (KI) were investigated. The surface properties of KX-ACs were determined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The pore structures and total pore volumes of the KX-ACs were analyzed using the N{sub 2} /77 K adsorption isotherms. The Hg{sup 0} removal efficiency of KBr-ACs and KI-ACs was studied under simulated flue gas conditions. The effects of KI and KBr loading, adsorption temperature, and flue gas components on Hg{sup 0} removal efficiency were also investigated. The results showed that the Hg{sup 0} removal efficiency of the ACs was significantly enhanced by KI or KBr impregnation, and KI-ACs showed higher Hg{sup 0} removal efficiency than KBr-ACs under the same conditions. An increase in KI or KBr loading and higher adsorption temperatures improved the Hg{sup 0} removal efficiency, indicating that chemisorption occurred due to the reaction between X− and Hg{sup 0}. The lower extent of Hg{sup 0} removal exhibited by the KBr-ACs than by the KI-ACs was due to the difficulty of Br{sub 2} formation on the surfaces.

  7. Measurements of gas and volatile element production rates from an irradiated molten lead and lead-bismuth spallation target with proton beams of 1 and 1.4 GeV

    International Nuclear Information System (INIS)

    Tall, Y.

    2008-03-01

    The integrated project EUROTRANS (European Research Programme for the Transmutation of High Level Nuclear Waste in an Accelerator Driven System) of the 6. EURATOM Framework Programme aims to demonstrate the transmutation of radioactive waste in ADS (Accelerator Driven Sub-critical system). It will carry out a first advanced design of an experimental facility to demonstrate the technical feasibility of transmutation, and will produce a conceptual design of an industrial facility dedicated to transmutation. An ADS consists of three fundamental elements: the accelerator of protons, the sub-critical core and the spallation target. SUBATECH (physique Sub-Atomique et des Technologies associees) laboratory is involved to the study of the chosen liquid lead-bismuth as a spallation ADS target. The irradiation of liquid lead-bismuth target with energetic proton beam generates in addition to neutrons, volatile and radioactive residues. In order to determine experimentally the production rates of gas and volatile elements following a spallation reaction in a lead-bismuth target, the experiment IS419 was performed at the ISOLDE facility at CERN (Centre Europeen de la Recherche Nucleaire). This experiment constitutes the frame of the thesis whose main objective is to assess and study the production and release rates of many gas and volatile element from the irradiated lead-bismuth target with an energetic proton beam. The obtained data are compared to Monte Carlo simulation code (MCNPX) results in order to test the intranuclear cascade model of Bertini and of Cugnon, and the evaporation options of Dresner and Schmidt. (author)

  8. Sources and mobility of carbonate melts beneath cratons, with implications for deep carbon cycling, metasomatism and rift initiation

    Science.gov (United States)

    Tappe, Sebastian; Romer, Rolf L.; Stracke, Andreas; Steenfelt, Agnete; Smart, Katie A.; Muehlenbachs, Karlis; Torsvik, Trond H.

    2017-05-01

    Kimberlite and carbonatite magmas that intrude cratonic lithosphere are among the deepest probes of the terrestrial carbon cycle. Their co-existence on thick continental shields is commonly attributed to continuous partial melting sequences of carbonated peridotite at >150 km depths, possibly as deep as the mantle transition zone. At Tikiusaaq on the North Atlantic craton in West Greenland, approximately 160 Ma old ultrafresh kimberlite dykes and carbonatite sheets provide a rare opportunity to study the origin and evolution of carbonate-rich melts beneath cratons. Although their Sr-Nd-Hf-Pb-Li isotopic compositions suggest a common convecting upper mantle source that includes depleted and recycled oceanic crust components (e.g., negative ΔεHf coupled with > + 5 ‰ δ7Li), incompatible trace element modelling identifies only the kimberlites as near-primary low-degree partial melts (0.05-3%) of carbonated peridotite. In contrast, the trace element systematics of the carbonatites are difficult to reproduce by partial melting of carbonated peridotite, and the heavy carbon isotopic signatures (-3.6 to - 2.4 ‰ δ13C for carbonatites versus -5.7 to - 3.6 ‰ δ13C for kimberlites) require open-system fractionation at magmatic temperatures. Given that the oxidation state of Earth's mantle at >150 km depth is too reduced to enable larger volumes of 'pure' carbonate melt to migrate, it is reasonable to speculate that percolating near-solidus melts of carbonated peridotite must be silicate-dominated with only dilute carbonate contents, similar to the Tikiusaaq kimberlite compositions (e.g., 16-33 wt.% SiO2). This concept is supported by our findings from the North Atlantic craton where kimberlite and other deeply derived carbonated silicate melts, such as aillikites, exsolve their carbonate components within the shallow lithosphere en route to the Earth's surface, thereby producing carbonatite magmas. The relative abundances of trace elements of such highly

  9. Cantilevered probe detector with piezoelectric element

    Science.gov (United States)

    Adams, Jesse D; Sulchek, Todd A; Feigin, Stuart C

    2013-04-30

    A disclosed chemical detection system for detecting a target material, such as an explosive material, can include a cantilevered probe, a probe heater coupled to the cantilevered probe, and a piezoelectric element disposed on the cantilevered probe. The piezoelectric element can be configured as a detector and/or an actuator. Detection can include, for example, detecting a movement of the cantilevered probe or a property of the cantilevered probe. The movement or a change in the property of the cantilevered probe can occur, for example, by adsorption of the target material, desorption of the target material, reaction of the target material and/or phase change of the target material. Examples of detectable movements and properties include temperature shifts, impedance shifts, and resonant frequency shifts of the cantilevered probe. The overall chemical detection system can be incorporated, for example, into a handheld explosive material detection system.

  10. A Plutonium Ceramic Target for MASHA

    International Nuclear Information System (INIS)

    Wilk, P A; Shaughnessy, D A; Moody, K J; Kenneally, J M; Wild, J F; Stoyer, M A; Patin, J B; Lougheed, R W; Ebbinghaus, B B; Landingham, R L; Oganessian, Y T; Yeremin, A V; Dmitriev, S N

    2004-01-01

    We are currently developing a plutonium ceramic target for the MASHA mass separator. The MASHA separator will use a thick plutonium ceramic target capable of tolerating temperatures up to 2000 C. Promising candidates for the target include oxides and carbides, although more research into their thermodynamic properties will be required. Reaction products will diffuse out of the target into an ion source, where they will then be transported through the separator to a position-sensitive focal-plane detector array. Experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments where the chemical properties of the heaviest elements are studied

  11. A guide to and review of the use of Multiwavelength Raman Spectroscopy for characterizing defective aromatic carbon solids : From graphene to amorphous carbons

    NARCIS (Netherlands)

    Merlen, A.; Buijnsters, J.G.; Pardanaud, C.

    2017-01-01

    sp2 hybridized carbons constitute a broad class of solid phases composed primarily of elemental carbon and can be either synthetic or naturally occurring. Some examples are graphite, chars, soot, graphene, carbon nanotubes, pyrolytic carbon, and diamond-like carbon. They vary from highly ordered to

  12. Targeting heavy rare earth elements in carbonatite complexes

    Science.gov (United States)

    Broom-Fendley, S.; Wall, F.; Gunn, A. G.; Dowman, E.

    2012-04-01

    The world's main sources of the rare earth elements (REE) are concentrated in carbonatite complexes. These have the advantages of high grade and tonnage, combined with low thorium contents, yet they are generally enriched in light rare earths (LREE). The heavy rare earths (HREE, which include Eu-Lu and Y) are more highly sought after because of their role in new and green technologies. HREE are predominantly extracted from ion-adsorption clays in China. These are small, low grade deposits, which are often illegally mined by artisans. Increased government control, environmental legislation and local demand for REE in China have led to high prices and global concerns about the security of supply of the HREE. Alternative sources of the HREE are poorly documented. We present a review of such targets, including: (1) 'abnormal' carbonatites; (2) areas around LREE-rich complexes such as breccia, fenite and latter stage veins; and (3) weathered carbonatites. At Lofdal, Namibia, carbonatite dykes contain xenotime-(Y) together with LREE minerals. The original chemistry of the carbonatite magma, coupled with late-stage magma and fluid evolution, seem to be controlling factors [1, 2]. The Khibina carbonatite, Kola Peninsula, Russia, is an example of where early LREE carbonatites become increasing HREE-enriched as magmas evolve to carbo-hydrothermal fluids [3]. Around carbonatite complexes in Malawi HREE enrichment can be found in breccia and in fenite. Breccia around Songwe shows areas with high Y/La ratios within the matrix caused by narrow zones of xenotime enrichment. Fenite around Kangankunde and Chilwa Island has higher HREE:LREE ratios than the carbonatite [4]. At weathered complexes, such as at Mount Weld in Western Australia, changes in both HREE concentration and LREE:HREE ratios are observed. In currently unworked sections of the deposit, the HREE mineral churchite (YPO4.H2O) has formed concentrations due to groundwater flow [5]. These areas of enrichment are

  13. Computational design of high efficiency release targets for use at ISOL facilities

    CERN Document Server

    Liu, Y

    1999-01-01

    This report describes efforts made at the Oak Ridge National Laboratory to design high-efficiency-release targets that simultaneously incorporate the short diffusion lengths, high permeabilities, controllable temperatures, and heat-removal properties required for the generation of useful radioactive ion beam (RIB) intensities for nuclear physics and astrophysics research using the isotope separation on-line (ISOL) technique. Short diffusion lengths are achieved either by using thin fibrous target materials or by coating thin layers of selected target material onto low-density carbon fibers such as reticulated-vitreous-carbon fiber (RVCF) or carbon-bonded-carbon fiber (CBCF) to form highly permeable composite target matrices. Computational studies that simulate the generation and removal of primary beam deposited heat from target materials have been conducted to optimize the design of target/heat-sink systems for generating RIBs. The results derived from diffusion release-rate simulation studies for selected t...

  14. Immunoglobulin kappa deleting element rearrangements in precursor-B acute lymphoblastic leukemia are stable targets for detection of minimal residual disease by real-time quantitative PCR

    NARCIS (Netherlands)

    van der Velden, V. H. J.; Willemse, M. J.; van der Schoot, C. E.; Hählen, K.; van Wering, E. R.; van Dongen, J. J. M.

    2002-01-01

    Immunoglobulin gene rearrangements are used as PCR targets for detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL). We Investigated the occurrence of monoclonal immunoglobulin kappa-deleting element (IGK-Kde) rearrangements by Southern blotting and PCR/heteroduplex

  15. Progress in ISOL target-ion source systems

    Energy Technology Data Exchange (ETDEWEB)

    Koester, U. [Institut Laue Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble Cedex 9 (France); ISOLDE, CERN, CH-1211 Geneve 23 (Switzerland)], E-mail: koester@ill.fr; Arndt, O. [HGF VISTARS and Institut fuer Kernchemie, Johannes-Gutenberg Universitaet Mainz, D-55128 Mainz (Germany); Bouquerel, E.; Fedoseyev, V.N. [ISOLDE, CERN, CH-1211 Geneve 23 (Switzerland); Franberg, H. [ISOLDE, CERN, CH-1211 Geneve 23 (Switzerland); Laboratory for Radio- and Environmental Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Joinet, A. [ISOLDE, CERN, CH-1211 Geneve 23 (Switzerland); Centre d' Etude Spatiale des Rayonnements, 9 Av. du Colonel Roche, F-31028 Toulouse Cedex 4 (France); Jost, C. [HGF VISTARS and Institut fuer Kernchemie, Johannes-Gutenberg Universitaet Mainz, D-55128 Mainz (Germany); Kerkines, I.S.K. [Laboratory of Physical Chemistry, National and Kapodistrian University of Athens, Department of Chemistry, Zografou 157 71, GR (Greece); Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, GA 30322 (United States); Kirchner, R. [Gesellschaft fuer Schwerionenforschung, Planckstr. 1, D-64291 Darmstadt (Germany)

    2008-10-15

    The heart of every ISOL (isotope separation on-line) facility is its target and ion source system. Its efficiency, selectivity and rapidity is decisive for the production of intense and pure ion beams of short-lived isotopes. Recent progress in ISOL target and ion source technology is discussed at the examples of radioactive ion beams of exotic zinc and tin isotopes that were purified by isothermal chromatography and molecular sideband separation respectively. An outlook is given to which other elements these purification methods are applicable.

  16. Progress in ISOL target-ion source systems

    International Nuclear Information System (INIS)

    Koester, U.; Arndt, O.; Bouquerel, E.; Fedoseyev, V.N.; Franberg, H.; Joinet, A.; Jost, C.; Kerkines, I.S.K.; Kirchner, R.

    2008-01-01

    The heart of every ISOL (isotope separation on-line) facility is its target and ion source system. Its efficiency, selectivity and rapidity is decisive for the production of intense and pure ion beams of short-lived isotopes. Recent progress in ISOL target and ion source technology is discussed at the examples of radioactive ion beams of exotic zinc and tin isotopes that were purified by isothermal chromatography and molecular sideband separation respectively. An outlook is given to which other elements these purification methods are applicable.

  17. Elemental and Organic Carbon Measurements at the Kosetice Observatory, Czech Republic within EU Projects in 2009-2014

    Science.gov (United States)

    Vana, M.; Holubova, A.; Cech, J.

    2016-12-01

    Carbonaceous aerosol (TC) is a complex mixture of many organics (OC fraction) and elemental carbon (EC). EC is a product of anthropogenic activities, especially incomplete combustion of fossil fuels by transport, heating, power plants, wood and biomass burning and agriculture activities. EC could have larger health impact than other PM constituents (Cassee et al., 2013). Carbonaceous aerosols also play an important role in climate change (Boucher et al., 2013). Kosetice Observatory, operated by the Czech Hydrometeorological Institute has been carrying out long-term air quality monitoring at the background scale the Czech Republic since 1988. Regular EC-OC measurement has been implementing within EU-projects EUSAAR and ACTRIS since 2009. Sampling frequency is every 6th day in fraction PM2,5 on 2 quartz-fibre filters. Since October 2011 the sampling on filters has been implementing behind the denuder catching the organic vapor. Amount of OC on back quartz fiber filter represents positive artifact by measurement without denuder and negative artifact by measurements with denuder. The analytical method is thermal-optical analysis. The samples are analyzed in CHMI Central Laboratories in Prague-Libuš using EC-OC Sunset Lab Dual Analyzer. Charring correction is made by laser transmission monitoring. Slightly decreasing tendency of EC-OC was found in the period under review (2009-2014). The mean annual concentration of total carbon (TC) in PM2,5 was 3,73 µg.m-3. The figure for elemental carbon (0,5 µg.m-3) represents the mean annual ratio of 13% on TC. EC-OC concentrations follow an annual course that reflects their emission levels, i.e. with maximums in winter and minimums in summer. The seasonal variation of EC/TC ratio ranges between 9,6 (summer) - 14,2% (winter). Mean TC ratio on PM2,5 total mass in the period under review was 29%, the highest ratios reached 50%. EC participated on PM2,5 total mass by 3,5% in average. 3D trajectories were used for sector analysis of

  18. Reactive magnetron sputtering of N-doped carbon thin films on quartz glass for transmission photocathode applications

    Science.gov (United States)

    Balalykin, N. I.; Huran, J.; Nozdrin, M. A.; Feshchenko, A. A.; Kobzev, A. P.; Sasinková, V.; Boháček, P.; Arbet, J.

    2018-03-01

    N-doped carbon thin films were deposited on a silicon substrate and quartz glass by RF reactive magnetron sputtering using a carbon target and an Ar+N2 gas mixture. During the magnetron sputtering, the substrate holder temperatures was kept at 800 °C. The carbon film thickness on the silicon substrate was about 70 nm, while on the quartz glass it was in the range 15 nm – 60 nm. The elemental concentration in the films was determined by RBS and ERD. Raman spectroscopy was used to evaluate the intensity ratios I D/I G of the D and G peaks of the carbon films. The transmission photocathodes prepared were placed in the hollow-cathode assembly of a Pierce-structure DC gun to produce photoelectrons. The quantum efficiency (QE) was calculated from the laser energy and cathode charge measured. The properties of the transmission photocathodes based on semitransparent N-doped carbon thin films on quartz glass and their potential for application in DC gun technology are discussed.

  19. 3D hybrid carbon composed of multigraphene bridged by carbon chains

    Directory of Open Access Journals (Sweden)

    Lingyu Liu

    2018-01-01

    Full Text Available The element carbon possesses various stable and metastable allotropes; some of them have been applied in diverse fields. The experimental evidences of both carbon chain and graphdiyne have been reported. Here, we reveal the mystery of an enchanting carbon allotrope with sp-, sp2-, and sp3-hybridized carbon atoms using a newly developed ab initio particle-swarm optimization algorithm for crystal structure prediction. This crystalline allotrope, namely m-C12, can be viewed as braided mesh architecture interwoven with multigraphene and carbon chains. The m-C12 meets the criteria for dynamic and mechanical stabilities and is energetically more stable than carbyne and graphdiyne. Analysis of the B/G and Poisson’s ratio indicates that this allotrope is ductile. Notably, m-C12 is a superconducting carbon with Tc of 1.13 K, which is rare in the family of carbon allotropes.

  20. 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.

  1. Trapped between two tails: trading off scientific uncertainties via climate targets

    International Nuclear Information System (INIS)

    Lemoine, Derek; McJeon, Haewon C

    2013-01-01

    Climate change policies must trade off uncertainties about future warming, about the social and ecological impacts of warming, and about the cost of reducing greenhouse gas emissions. We show that laxer carbon targets produce broader distributions for climate damages, skewed towards severe outcomes. However, if potential low-carbon technologies fill overlapping niches, then more stringent carbon targets produce broader distributions for the cost of reducing emissions, skewed towards high-cost outcomes. We use the technology-rich GCAM integrated assessment model to assess the robustness of 450 and 500 ppm carbon targets to each uncertain factor. The 500 ppm target provides net benefits across a broad range of futures. The 450 ppm target provides net benefits only when impacts are greater than conventionally assumed, when multiple technological breakthroughs lower the cost of abatement, or when evaluated with a low discount rate. Policy evaluations are more sensitive to uncertainty about abatement technology and impacts than to uncertainty about warming. (letter)

  2. Trapped between two tails: trading off scientific uncertainties via climate targets

    Science.gov (United States)

    Lemoine, Derek; McJeon, Haewon C.

    2013-09-01

    Climate change policies must trade off uncertainties about future warming, about the social and ecological impacts of warming, and about the cost of reducing greenhouse gas emissions. We show that laxer carbon targets produce broader distributions for climate damages, skewed towards severe outcomes. However, if potential low-carbon technologies fill overlapping niches, then more stringent carbon targets produce broader distributions for the cost of reducing emissions, skewed towards high-cost outcomes. We use the technology-rich GCAM integrated assessment model to assess the robustness of 450 and 500 ppm carbon targets to each uncertain factor. The 500 ppm target provides net benefits across a broad range of futures. The 450 ppm target provides net benefits only when impacts are greater than conventionally assumed, when multiple technological breakthroughs lower the cost of abatement, or when evaluated with a low discount rate. Policy evaluations are more sensitive to uncertainty about abatement technology and impacts than to uncertainty about warming.

  3. Preparation of very pure active carbon

    International Nuclear Information System (INIS)

    Sloot, H.A. van der; Hoede, D.; Zonderhuis, J.; Meijer, C.

    1980-02-01

    The preparation of very pure active carbon is described. Starting from polyvinylidene chloride active carbon is prepared by carbonization in a nitrogen atmosphere, grinding, sieving and activation of the powder fraction with CO 2 at 950 0 to approximately 50% burn-off. The concentrations of trace and major elements are reduced to the ppb and ppm level, respectively. In the present set-up 100 g of carbon grains and approximately 50 g of active carbon powder can be produced weekly

  4. Environmental implications of carbon limits on market ...

    Science.gov (United States)

    Combined heat and power (CHP) is promoted as an economical, energy-efficient option for combating climate change. To fully examine the viability of CHP as a clean-technology solution, its market potential and impacts need to be analyzed as part of scenarios of the future energy system, particularly those with policies limiting greenhouse gas (GHG) emissions. This paper develops and analyzes scenarios using a bottom-up, technology rich optimization model of the U.S. energy system. Two distinct carbon reduction goals were set up for analysis. In Target 1, carbon emission reduction goals were only included for the electric sector. In Target 2, carbon emission reduction goals were set across the entire energy system with the target patterned after the U.S.’s commitment to reducing GHG emissions as part of the Paris Agreement reached at the COP21 summit. From a system-wide carbon reduction standpoint, Target 2 is significantly more stringent. In addition, these scenarios examine the implications of various CHP capacity expansion and contraction assumptions and energy prices. The largest CHP capacity expansion are observed in scenarios that included Target 1, but investments were scaled back in scenarios that incorporated Target 2. The latter scenario spurred rapid development of zero-emissions technologies within the electric sector, and purchased electricity increased dramatically in many end-use sectors. The results suggest that CHP may play a role in a carbon-c

  5. a Plutonium Ceramic Target for Masha

    Science.gov (United States)

    Wilk, P. A.; Shaughnessy, D. A.; Moody, K. J.; Kenneally, J. M.; Wild, J. F.; Stoyer, M. A.; Patin, J. B.; Lougheed, R. W.; Ebbinghaus, B. B.; Landingham, R. L.; Oganessian, Yu. Ts.; Yeremin, A. V.; Dmitriev, S. N.

    2005-09-01

    We are currently developing a plutonium ceramic target for the MASHA mass separator. The MASHA separator will use a thick plutonium ceramic target capable of tolerating temperatures up to 2000 °C. Promising candidates for the target include oxides and carbides, although more research into their thermodynamic properties will be required. Reaction products will diffuse out of the target into an ion source, where they will then be transported through the separator to a position-sensitive focal-plane detector array. Experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments where the chemical properties of the heaviest elements are studied.

  6. Carbon finance options in renewable energy

    International Nuclear Information System (INIS)

    Nahar, P.

    2010-01-01

    The Kyoto Protocol splits the world into two categories, notably Annex 1 with binding targets; and non-Annex 1 without any binding targets. This presentation discussed the Kyoto Protocol, with particular reference to the flexibility mechanisms which allow countries to achieve their emission targets in a cost effective way through emission trading, joint implementation, or clean development mechanisms (CDM). The CDM was outlined in detail in terms of how it works. The CDM key concepts include baseline use, additionality, and monitoring. Reasons for risk and CDM renewable energy projects were also outlined. Other topics that were presented included the impact of carbon finance; United States federal climate policy; European Union policy; EVO structured carbon; portfolio management; and EVO structured carbon. tabs., figs.

  7. Thermal characteristics of carbon fiber reinforced epoxy containing multi-walled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Jin-woo Lee

    2018-06-01

    Full Text Available The material with irregular atomic structures such as polymer material exhibits low thermal conductivity because of the complex structural properties. Even materials with same atomic configurations, thermal conductivity may be different based on their structural properties. It is expected that nanoparticles with conductivity will change non-conductive polymer base materials to electrical conductors, and improve the thermal conductivity even with extremely small filling amount. Nano-composite materials contain nanoparticles with a higher surface ratio which makes the higher interface percentage to the total surface of nanoparticles. Therefore, thermal resistance of the interface becomes a dominating factor determines the effective thermal conductivity in nano-composite materials. Carbon fiber has characteristic of resistance or magnetic induction and Also, Carbon nanotube (CNT has electronic and thermal property. It can be applied for heating system. These characteristic are used as heating composite. In this research, the exothermic characteristics of Carbon fiber reinforced composite added CNT were evaluated depend on CNT length and particle size. It was found that the CNT dispersed in the resin reduces the resistance between the interfaces due to the decrease in the total resistance of the heating element due to the addition of CNTs. It is expected to improve the life and performance of the carbon fiber composite material as a result of the heating element resulting from this paper. Keywords: Carbon Nanotube (CNT, Carbon Fiber Reinforcement Plastic (CFRP, Heater, Exothermic characteristics

  8. 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.

  9. 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.

  10. Target preparation

    International Nuclear Information System (INIS)

    Hinn, G.M.

    1984-01-01

    A few of the more interesting of the 210 targets prepared in the Laboratory last year are listed. In addition the author continues to use powdered silver mixed with /sup 9,10/BeO to produce sources for accelerator radio dating of Alaskan and South Polar snow. Currently, he is trying to increase production by multiple sample processing. Also the author routinely makes 3 μg/cm 2 cracked slacked carbon stripper foils and is continuing research with some degree of success in making enriched 28 Si targets starting with the oxide

  11. Predicting ambient aerosol thermal-optical reflectance measurements from infrared spectra: elemental carbon

    Science.gov (United States)

    Dillner, A. M.; Takahama, S.

    2015-10-01

    Elemental carbon (EC) is an important constituent of atmospheric particulate matter because it absorbs solar radiation influencing climate and visibility and it adversely affects human health. The EC measured by thermal methods such as thermal-optical reflectance (TOR) is operationally defined as the carbon that volatilizes from quartz filter samples at elevated temperatures in the presence of oxygen. Here, methods are presented to accurately predict TOR EC using Fourier transform infrared (FT-IR) absorbance spectra from atmospheric particulate matter collected on polytetrafluoroethylene (PTFE or Teflon) filters. This method is similar to the procedure developed for OC in prior work (Dillner and Takahama, 2015). Transmittance FT-IR analysis is rapid, inexpensive and nondestructive to the PTFE filter samples which are routinely collected for mass and elemental analysis in monitoring networks. FT-IR absorbance spectra are obtained from 794 filter samples from seven Interagency Monitoring of PROtected Visual Environment (IMPROVE) sites collected during 2011. Partial least squares regression is used to calibrate sample FT-IR absorbance spectra to collocated TOR EC measurements. The FT-IR spectra are divided into calibration and test sets. Two calibrations are developed: one developed from uniform distribution of samples across the EC mass range (Uniform EC) and one developed from a uniform distribution of Low EC mass samples (EC < 2.4 μg, Low Uniform EC). A hybrid approach which applies the Low EC calibration to Low EC samples and the Uniform EC calibration to all other samples is used to produce predictions for Low EC samples that have mean error on par with parallel TOR EC samples in the same mass range and an estimate of the minimum detection limit (MDL) that is on par with TOR EC MDL. For all samples, this hybrid approach leads to precise and accurate TOR EC predictions by FT-IR as indicated by high coefficient of determination (R2; 0.96), no bias (0.00 μg m-3, a

  12. Dissolved organic carbon and major and trace elements in peat porewater of sporadic, discontinuous, and continuous permafrost zones of western Siberia

    Science.gov (United States)

    Raudina, Tatiana V.; Loiko, Sergey V.; Lim, Artyom G.; Krickov, Ivan V.; Shirokova, Liudmila S.; Istigechev, Georgy I.; Kuzmina, Daria M.; Kulizhsky, Sergey P.; Vorobyev, Sergey N.; Pokrovsky, Oleg S.

    2017-07-01

    Mobilization of dissolved organic carbon (DOC) and related trace elements (TEs) from the frozen peat to surface waters in the permafrost zone is expected to enhance under ongoing permafrost thaw and active layer thickness (ALT) deepening in high-latitude regions. The interstitial soil solutions are efficient tracers of ongoing bio-geochemical processes in the critical zone and can help to decipher the intensity of carbon and metals migration from the soil to the rivers and further to the ocean. To this end, we collected, across a 640 km latitudinal transect of the sporadic to continuous permafrost zone of western Siberia peatlands, soil porewaters from 30 cm depth using suction cups and we analyzed DOC, dissolved inorganic carbon (DIC), and 40 major elements and TEs in 0.45 µm filtered fraction of 80 soil porewaters. Despite an expected decrease in the intensity of DOC and TE mobilization from the soil and vegetation litter to the interstitial fluids with the increase in the permafrost coverage and a decrease in the annual temperature and ALT, the DOC and many major and trace elements did not exhibit any distinct decrease in concentration along the latitudinal transect from 62.2 to 67.4° N. The DOC demonstrated a maximum of concentration at 66° N, on the border of the discontinuous/continuous permafrost zone, whereas the DOC concentration in peat soil solutions from the continuous permafrost zone was equal to or higher than that in the sporadic/discontinuous permafrost zone. Moreover, a number of major (Ca, Mg) and trace (Al, Ti, Sr, Ga, rare earth elements (REEs), Zr, Hf, Th) elements exhibited an increasing, not decreasing, northward concentration trend. We hypothesize that the effects of temperature and thickness of the ALT are of secondary importance relative to the leaching capacity of peat, which is in turn controlled by the water saturation of the peat core. The water residence time in peat pores also plays a role in enriching the fluids in some elements

  13. Dissolved organic carbon and major and trace elements in peat porewater of sporadic, discontinuous, and continuous permafrost zones of western Siberia

    Directory of Open Access Journals (Sweden)

    T. V. Raudina

    2017-07-01

    Full Text Available Mobilization of dissolved organic carbon (DOC and related trace elements (TEs from the frozen peat to surface waters in the permafrost zone is expected to enhance under ongoing permafrost thaw and active layer thickness (ALT deepening in high-latitude regions. The interstitial soil solutions are efficient tracers of ongoing bio-geochemical processes in the critical zone and can help to decipher the intensity of carbon and metals migration from the soil to the rivers and further to the ocean. To this end, we collected, across a 640 km latitudinal transect of the sporadic to continuous permafrost zone of western Siberia peatlands, soil porewaters from 30 cm depth using suction cups and we analyzed DOC, dissolved inorganic carbon (DIC, and 40 major elements and TEs in 0.45 µm filtered fraction of 80 soil porewaters. Despite an expected decrease in the intensity of DOC and TE mobilization from the soil and vegetation litter to the interstitial fluids with the increase in the permafrost coverage and a decrease in the annual temperature and ALT, the DOC and many major and trace elements did not exhibit any distinct decrease in concentration along the latitudinal transect from 62.2 to 67.4° N. The DOC demonstrated a maximum of concentration at 66° N, on the border of the discontinuous/continuous permafrost zone, whereas the DOC concentration in peat soil solutions from the continuous permafrost zone was equal to or higher than that in the sporadic/discontinuous permafrost zone. Moreover, a number of major (Ca, Mg and trace (Al, Ti, Sr, Ga, rare earth elements (REEs, Zr, Hf, Th elements exhibited an increasing, not decreasing, northward concentration trend. We hypothesize that the effects of temperature and thickness of the ALT are of secondary importance relative to the leaching capacity of peat, which is in turn controlled by the water saturation of the peat core. The water residence time in peat pores also plays a role in enriching the

  14. 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

  15. A probability of synthesis of the superheavy element Z = 124

    Energy Technology Data Exchange (ETDEWEB)

    Manjunatha, H.C. [Government College for Women, Department of Physics, Kolar, Karnataka (India); Sridhar, K.N. [Government First Grade College, Department of Physics, Kolar, Karnataka (India)

    2017-10-15

    We have studied the fusion cross section, evaporation residue cross section, compound nucleus formation probability (P{sub CN}) and survival probability (P{sub sur}) of different projectile target combinations to synthesize the superheavy element Z=124. Hence, we have identified the most probable projectile-target combination to synthesize the superheavy element Z = 124. To synthesize the superheavy element Z=124, the most probable projectile target combinations are Kr+Ra, Ni+Cm, Se+Th, Ge+U and Zn+Pu. We hope that our predictions may be a guide for the future experiments in the synthesis of superheavy nuclei Z = 124. (orig.)

  16. New Fragment Separation Technology for Superheavy Element Research

    International Nuclear Information System (INIS)

    Shaughnessy, D A; Moody, K J; Henderson, R A; Kenneally, J M; Landrum, J H; Lougheed, R W; Patin, J B; Stoyer, M A; Stoyer, N J; Wild, J F; Wilk, P A

    2008-01-01

    This project consisted of three major research areas: (1) development of a solid Pu ceramic target for the MASHA separator, (2) chemical separation of nuclear decay products, and (3) production of new isotopes and elements through nuclear reactions. There have been 16 publications as a result of this project, and this collection of papers summarizes our accomplishments in each of the three areas of research listed above. The MASHA (Mass Analyzer for Super-Heavy Atoms) separator is being constructed at the U400 Cyclotron at the Flerov Laboratory of Nuclear Reactions in Dubna, Russia. The purpose of the separator is to physically separate the products from nuclear reactions based on their isotopic masses rather than their decay characteristics. The separator was designed to have a separation between isotopic masses of ±0.25 amu, which would enable the mass of element 114 isotopes to be measured with outstanding resolution, thereby confirming their discovery. In order to increase the production rate of element 114 nuclides produced via the 244 Pu+ 48 Ca reaction, a new target technology was required. Instead of a traditional thin actinide target, the MASHA separator required a thick, ceramic-based Pu target that was thick enough to increase element 114 production while still being porous enough to allow reaction products to migrate out of the target and travel through the separator to the detector array located at the back end. In collaboration with UNLV, we began work on development of the Pu target for MASHA. Using waste-form synthesis technology, we began by creating zirconia-based matrices that would form a ceramic with plutonium oxide. We used samarium oxide as a surrogate for Pu and created ceramics that had varying amounts of the starting materials in order to establish trends in material density and porosity. The results from this work are described in more detail in Refs. [1,4,10]. Unfortunately, work on MASHA was delayed in Russia because it was found that

  17. How costly are carbon offsets? A meta-analysis of carbon forest sinks

    NARCIS (Netherlands)

    Kooten, van G.C.; Eagle, A.J.; Manley, J.; Smolak, T.

    2004-01-01

    Carbon terrestrial sinks are seen as a low-cost alternative to fuel switching and reduced fossil fuel use for lowering atmospheric CO2. As a result of agreements reached at Bonn and Marrakech, carbon offsets have taken on much greater importance in meeting Kyoto targets for the first commitment

  18. Tradeable carbon permits

    International Nuclear Information System (INIS)

    Koutstaal, P.R.

    1995-01-01

    The research project on tradeable carbon permits has focused on three elements. First of all, the practical implications of designing a system of tradeable emission permits for reducing CO2 has been studied. In the second part, the consequences of introducing a system of tradeable carbon permits for entry barriers have been considered. Finally, the institutional requirements and welfare effects of coordination of CO2 abatement in a second-best world have been examined

  19. Carbon dioxide, climate and the deep ocean circulation: Carbon chemistry model

    International Nuclear Information System (INIS)

    Menawat, A.S.

    1992-01-01

    The objective of this study was to investigate the role of oceanic carbon chemistry in modulating the atmospheric levels of CO 2 . It is well known that the oceans are the primary sink of the excess carbon pumped into the atmosphere since the beginning of the industrial period. The suspended particulate and the dissolved organic matters in the deep ocean play important roles as carriers of carbon and other elements critical to the fate of CO 2 . In addition, the suspended particulate matter provides sites for oxidation-reduction reactions and microbial activities. The problem is of an intricate system with complex chemical, physical and biological processes. This report describes a methodology to describe the interconversions of different forms of the organic and inorganic nutrients, that may be incorporated in the ocean circulation models. Our approach includes the driving force behind the transfers in addition to balancing the elements. Such thermodynamic considerations of describing the imbalance in the chemical potentials is a new and unique feature of our approach

  20. A yeast model for target-primed (non-LTR retrotransposition

    Directory of Open Access Journals (Sweden)

    Busby Jason N

    2007-08-01

    Full Text Available Abstract Background Target-primed (non-LTR retrotransposons, such as the human L1 element, are mobile genetic elements found in many eukaryotic genomes. They are often present in large numbers and their retrotransposition can cause mutations and genomic rearrangements. Despite their importance, many aspects of their replication are not well understood. Results We have developed a yeast model system for studying target-primed retrotransposons. This system uses the Zorro3 element from Candida albicans. A cloned copy of Zorro3, tagged with a retrotransposition indicator gene, retrotransposes at a high frequency when introduced into an appropriate C. albicans host strain. Retrotransposed copies of the tagged element exhibit similar features to the native copies, indicating that the natural retrotransposition pathway is being used. Retrotransposition is dependent on the products of the tagged element's own genes and is highly temperature-regulated. The new assay permits the analysis of the effects of specific mutations introduced into the cloned element. Conclusion This Zorro3 retrotransposition assay system complements previously available target-primed retrotransposition assays. Due to the relative simplicity of the growth, manipulation and analysis of yeast cells, the system should advance our understanding of target-primed retrotransposition.

  1. Rotating target wheel system for super-heavy element production at ATLAS

    CERN Document Server

    Greene, J P; Falout, J; Janssens, R V F

    2004-01-01

    A new scattering chamber housing a large diameter rotating target wheel has been designed and constructed in front of the Fragment Mass Analyzer (FMA) for the production of very heavy nuclei (Z greater than 100) using beams from the Argonne Tandem Linear Accelerator System (ATLAS). In addition to the target and drive system, the chamber is extensively instrumented in order to monitor target performance and deterioration. Capabilities also exist to install rotating entrance and exit windows for gas cooling of the target within the scattering chamber. The design and initial tests are described.

  2. 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.

  3. 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.

  4. Discovery of element 112

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S. [GSI, Darmstadt (Germany)

    1996-12-31

    The new elements 110, 111, and 112 were synthesized and unambiguously identified in experiments at SHIP. Due to strong shell effects the dominant decay mode is not fission, but emission of alpha particles. Theoretical investigations predict that maximum shell effects should exist in nuclei near proton number 114 and neutron number 184. Measurements give hope that isotopes of element 114 close to the island of spherical Superheavy Elements could be produced by fusion reactions using {sup 118}Pb as target. systematic studies of the reaction cross-sections indicate that transfer of nucleons is the important process to initiate the fusion.

  5. Finite element modelling of the mechanics of discrete carbon nanotubes filled with ZnS and comparison with experimental observations

    KAUST Repository

    Monteiro, André O.; Da Costa, Pedro M. F. J.; Cachim, Paulo Barreto

    2013-01-01

    The mechanical response to a uniaxial compressive force of a single carbon nanotube (CNT) filled (or partially-filled) with ZnS has been modelled. A semi-empirical approach based on the finite element method was used whereby modelling outcomes were closely matched to experimental observations. This is the first example of the use of the continuum approach to model the mechanical behaviour of discrete filled CNTs. In contrast to more computationally demanding methods such as density functional theory or molecular dynamics, our approach provides a viable and expedite alternative to model the mechanics of filled multi-walled CNTs. © 2013 Springer Science+Business Media New York.

  6. Finite element modelling of the mechanics of discrete carbon nanotubes filled with ZnS and comparison with experimental observations

    KAUST Repository

    Monteiro, André O.

    2013-09-25

    The mechanical response to a uniaxial compressive force of a single carbon nanotube (CNT) filled (or partially-filled) with ZnS has been modelled. A semi-empirical approach based on the finite element method was used whereby modelling outcomes were closely matched to experimental observations. This is the first example of the use of the continuum approach to model the mechanical behaviour of discrete filled CNTs. In contrast to more computationally demanding methods such as density functional theory or molecular dynamics, our approach provides a viable and expedite alternative to model the mechanics of filled multi-walled CNTs. © 2013 Springer Science+Business Media New York.

  7. Multiple Target Laser Designator (MTLD)

    Science.gov (United States)

    2007-03-01

    Optimized Liquid Crystal Scanning Element Optimize the Nonimaging Predictive Algorithm for Target Ranging, Tracking, and Position Estimation...commercial potential. 3.0 PROGRESS THIS QUARTER 3.1 Optimization of Nonimaging Holographic Antenna for Target Tracking and Position Estimation (Task 6) In

  8. 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.

  9. A novel activated carbon for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Haijie [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); Liu, Enhui, E-mail: liuenhui99@sina.com.cn [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); Xiang, Xiaoxia; Huang, Zhengzheng; Tian, Yingying; Wu, Yuhu; Wu, Zhilian; Xie, Hui [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer A novel activated carbon was prepared from phenol-melamine-formaldehyde resin. Black-Right-Pointing-Pointer The carbon has large surface area with microporous, and high heteroatom content. Black-Right-Pointing-Pointer Heteroatom-containing functional groups can improve the pseudo-capacitance. Black-Right-Pointing-Pointer Physical and chemical properties lead to the good electrochemical properties. -- Abstract: A novel activated carbon has been prepared by simple carbonization and activation of phenol-melamine-formaldehyde resin which is synthesized by the condensation polymerization method. The morphology, thermal stability, surface area, elemental composition and surface chemical composition of samples have been investigated by scanning electron microscope, thermogravimetry and differential thermal analysis, Brunauer-Emmett-Teller measurement, elemental analysis and X-ray photoelectron spectroscopy, respectively. Electrochemical properties have been studied by cyclic voltammograms, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements in 6 mol L{sup -1} potassium hydroxide. The activated carbon shows good capacitive behavior and the specific capacitance is up to 210 F g{sup -1}, which indicates that it may be a promising candidate for supercapacitors.

  10. 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

  11. lumpGEM: Systematic generation of subnetworks and elementally balanced lumped reactions for the biosynthesis of target metabolites.

    Directory of Open Access Journals (Sweden)

    Meric Ataman

    2017-07-01

    Full Text Available In the post-genomic era, Genome-scale metabolic networks (GEMs have emerged as invaluable tools to understand metabolic capabilities of organisms. Different parts of these metabolic networks are defined as subsystems/pathways, which are sets of functional roles to implement a specific biological process or structural complex, such as glycolysis and TCA cycle. Subsystem/pathway definition is also employed to delineate the biosynthetic routes that produce biomass building blocks. In databases, such as MetaCyc and SEED, these representations are composed of linear routes from precursors to target biomass building blocks. However, this approach cannot capture the nested, complex nature of GEMs. Here we implemented an algorithm, lumpGEM, which generates biosynthetic subnetworks composed of reactions that can synthesize a target metabolite from a set of defined core precursor metabolites. lumpGEM captures balanced subnetworks, which account for the fate of all metabolites along the synthesis routes, thus encapsulating reactions from various subsystems/pathways to balance these metabolites in the metabolic network. Moreover, lumpGEM collapses these subnetworks into elementally balanced lumped reactions that specify the cost of all precursor metabolites and cofactors. It also generates alternative subnetworks and lumped reactions for the same metabolite, accounting for the flexibility of organisms. lumpGEM is applicable to any GEM and any target metabolite defined in the network. Lumped reactions generated by lumpGEM can be also used to generate properly balanced reduced core metabolic models.

  12. Energy efficiency and carbon trading potential in Malaysia

    International Nuclear Information System (INIS)

    Oh, Tick Hui; Chua, Shing Chyi

    2010-01-01

    The damage inflicted by global warming is happening far faster than any experts have predicted or anticipated. Since the Kyoto Protocol was signed in 1997 to fight global warming through reducing global greenhouse gases (GHGs) emission, the world climate pattern has worsened at an accelerated rate beyond expectation. While developed countries sanctioned by the protocol are committed to achieve their GHG emission targets, developing nations play similar roles on a voluntary basis. Since almost all of the GHGs emissions come from energy sector, it is obvious that energy policy and related regulatory frameworks play imperative roles in realizing the Kyoto Protocol objectives. With carbon dioxide (CO 2 ) touted as the main remedy in the GHGs emissions, it is only reasonable that carbon trading becomes the essential element in the Protocol. Recently a milestone is marked in the Kyoto Protocol with the 2009 Climate Summit in Copenhagen, Denmark, with all participating countries further committed themselves in fulfilling the protocol's obligations before the commitment period due in 2012. It is worthwhile to review the various energy efficiency efforts and carbon trading potential in Malaysia, a country which although does not bear any obligation, has ratified and lauded the cause of the protocol. Malaysia as a developing nation is seen as a direct beneficiary from carbon trading and in this paper, how the country energy policies have evolved over the years with concerted efforts from the government to minimize its carbon footprint through numerous energy efficiency implementations are discussed in length. The impact from the 2009 Climate Summit on Malaysia is also briefed. (author)

  13. Climate constraints on the carbon intensity of economic growth

    International Nuclear Information System (INIS)

    Rozenberg, Julie; Narloch, Ulf; Hallegatte, Stephane; Davis, Steven J

    2015-01-01

    Development and climate goals together constrain the carbon intensity of production. Using a simple and transparent model that represents committed CO 2 emissions (future emissions expected to come from existing capital), we explore the carbon intensity of production related to new capital required for different temperature targets across several thousand scenarios. Future pathways consistent with the 2 °C target which allow for continued gross domestic product growth require early action to reduce carbon intensity of new production, and either (i) a short lifetime of energy and industry capital (e.g. early retrofit of coal power plants), or (ii) large negative emissions after 2050 (i.e. rapid development and dissemination of carbon capture and sequestration). To achieve the 2 °C target, half of the scenarios indicate a carbon intensity of new production between 33 and 73 g CO 2 /$—much lower than the global average today, at 360 g CO 2 /$. The average lifespan of energy capital (especially power plants), and industry capital, are critical because they commit emissions far into the future and reduce the budget for new capital emissions. Each year of lifetime added to existing, carbon intensive capital, decreases the carbon intensity of new production required to meet a 2 °C carbon budget by 1.0–1.5 g CO 2 /$, and each year of delaying the start of mitigation decreases the required CO 2 intensity of new production by 20–50 g CO 2 /$. Constraints on the carbon intensity of new production under a 3 °C target are considerably relaxed relative to the 2 °C target, but remain daunting in comparison to the carbon intensity of the global economy today. (letter)

  14. 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.

  15. Endogenous Technological Progress with Uncertainty and Carbon Abatement Polices

    Energy Technology Data Exchange (ETDEWEB)

    Cho, G.L. [Korea Energy Economics Institute, Euiwang (Korea)

    2001-11-01

    Most greenhouse gas abatement policy models tend to neglect a potentially important element that is relevant to the induced technology changes(ITC). These models that incorporate technological change treat such a change as autonomous, that is, unaffected by changes in prices brought about by policy reforms. However, climate change policies can create economic incentives to engage in more extensive R and D oriented toward the discovery of new production techniques that mitigate a reliance on convectional fuels, ultimately resulting in impacts on the policies themselves. In order to investigate the significance of induced technology for the attractiveness of abatement policies, this study develop the multi-sectoral dynamic CGE model by incorporating two characteristics of technological progress: the endogenous growth model with externality of technology in Romer (1986) and Lucas(1988) and the technological changes resulting from profit maximizing investment in R and D in Rebelo(1991) and Jones and Manuelli(1990). Furthermore, technological progress is affected by not only the economical factors but also the political and institutional system that cannot be captured in this model. This study considers such uncertainty in the technological progress as technology shock as in RBC school. This study shows that the presence of ITC implies lower costs of achieving a given abatement target in terms of the reduction cost per ton of carbon and GDP losses. The presence of ITC reduces the GDP losses by 0.9%p{approx}1.5%p compared with the absence of the ITC. As the abatement target is substantially high, R and D is reduced significantly even in the presence of ITC. Therefore, it is necessary to seriously consider the tax recycling for enhancing R and D investment, which minimizes the GDP losses. The reduction cost is highly sensitive to the uncertainty in technological progress. The technology shock leads the reduction cost to widely vary, in terms of standard deviation, 3

  16. Target preparation and characterization for multielemental analysis of liquid samples by use of accelerators

    CERN Document Server

    Liendo, J A; Fletcher, N R; Gómez, J; Caussyn, D D; Myers, S H; Castelli, C; Sajo-Bohus, L

    1999-01-01

    Elastic scattering at forward angles is tested as a useful alternative method to characterize liquid samples of scientific and/or technological interest. Solid residues of such samples deposited on light backings have been bombarded with 16 MeV sup 7 Li and 24 MeV sup 1 sup 6 O beams in order to determine the experimental configuration giving the best elemental mass separation. The elastically scattered ions were detected at 16 deg. , 20 deg. and 28 deg. with surface barrier detectors. The ratios between the mass separation and the line width obtained in the spectral region between carbon and oxygen varied between 2 and 13. This method is particularly useful for an accurate elemental characterization below sodium which is beyond the scope of standard techniques such as PIXE and TXRF provided the ion beam type, its kinetic energy and the target thickness are considered simultaneously.

  17. Boron ion irradiation induced structural and surface modification of glassy carbon

    International Nuclear Information System (INIS)

    Kalijadis, Ana; Jovanović, Zoran; Cvijović-Alagić, Ivana; Laušević, Zoran

    2013-01-01

    The incorporation of boron into glassy carbon was achieved by irradiating two different types of targets: glassy carbon polymer precursor and carbonized glassy carbon. Targets were irradiated with a 45 keV B 3+ ion beam in the fluence range of 5 × 10 15 –5 × 10 16 ions cm −2 . For both types of targets, the implanted boron was located in a narrow region under the surface. Following irradiation, the polymer was carbonized under the same condition as the glassy carbon samples (at 1273 K) and examined by Raman spectroscopy, temperature programmed desorption, hardness and cyclic voltammetry measurements. Structural analysis showed that during the carbonization process of the irradiated polymers, boron is substitutionally incorporated into the glassy carbon structure, while for irradiated carbonized glassy carbon samples, boron irradiation caused an increase of the sp 3 carbon fraction, which is most pronounced for the highest fluence irradiation. Further analyses showed that different nature of boron incorporation, and thus changed structural parameters, are crucial for obtaining glassy carbon samples with modified mechanical, chemical and electrochemical properties over a wide range

  18. Utilization of carbon/carbon composites in nuclear simulation fuel rods

    International Nuclear Information System (INIS)

    Polidoro, H.A.; Otani, S.; Rezende, M.C.; Ferreira, S.R.; Otani, C.

    1988-01-01

    Thermo-hydraulic problems, in nuclear plants are normally analysed by using electrically heated rods. Carbon/carbon composites were used to make heating elements for testing by indirect heating up to a heat flux of 100 W/cm 2 . It is easy to verify that this value can be exceed if the choice of the complementary materials for insulator and cladding were improved. The swaging process used to reduce the cladding diameter prevented the fabrication of graphite heater rods. (author) [pt

  19. Diagnostic Evaluation of Carbon Sources in CMAQ

    Science.gov (United States)

    Traditional monitoring networks measure only total elemental carbon (EC) and organic carbon (OC) routinely. Diagnosing model biases with such limited information is difficult. Measurements of organic tracer compounds have recently become available and allow for more detailed di...

  20. Abundance analyses of thirty cool carbon stars

    International Nuclear Information System (INIS)

    Utsumi, Kazuhiko

    1985-01-01

    The results were previously obtained by use of the absolute gf-values and the cosmic abundance as a standard. These gf-values were found to contain large systematic errors, and as a result, the solar photospheric abundances were revised. Our previous results, therefore, must be revised by using new gf-values, and abundance analyses are extended for as many carbon stars as possible. In conclusion, in normal cool carbon stars heavy metals are overabundant by factors of 10 - 100 and rare-earth elements are overabundant by a factor of about 10, and in J-type cool carbon stars, C 12 /C 13 ratio is smaller, C 2 and CN bands and Li 6708 are stronger than in normal cool carbon stars, and the abundances of s-process elements with respect to Fe are nearly normal. (Mori, K.)

  1. Removal of alkaline-earth elements by a carbonate precipitation in a chloride molten salt

    International Nuclear Information System (INIS)

    Yung-Zun Cho; In-Tae Kim; Hee-Chui Yang; Hee-Chui Eun; Hwan-Seo Park; Eung-Ho Kim

    2007-01-01

    Separation of some alkaline-earth chlorides (Sr, Ba) was investigated by using carbonate injection method in LiCl-KCl eutectic and LiCl molten salts. The effects of the injected molar ratio of carbonate([K 2 (or Li 2 )CO 3 /Sr(or Ba)Cl 2 ]) and the temperature(450-750 deg.) on the conversion ratio of the Sr or Ba carbonate were determined. In addition, the form of the Sr and Ba carbonate resulting from the carbonation reaction with carbonates was identified via XRD and SEM-EDS analysis. In these experiments, the carbonate injection method can remove Sr and Ba chlorides effectively over 99% in both LiCl-KCl eutectic and LiCl molten salt conditions. When Sr and Ba were co-presented in the eutectic molten salt, they were carbonated in a form of Ba 0.5 Sr 0.3 CO 3 . And when Sr was present in LiCl molten salt, it was carbonated in the form of SrCO 3 . Carbonation ratio increased with a decreasing temperature and it was more favorable in the case of a K 2 CO 3 injection than that of Li 2 CO 3 . Based on this experiment, it is postulated that carbonate precipitation method has the potential for removing alkali-earth chlorides from LiCl-KCl eutectic and LiCl molten salts. (authors)

  2. Standardisation of a European measurement method for organic carbon and elemental carbon in ambient air: results of the field trial campaign and the determination of a measurement uncertainty and working range.

    Science.gov (United States)

    Brown, Richard J C; Beccaceci, Sonya; Butterfield, David M; Quincey, Paul G; Harris, Peter M; Maggos, Thomas; Panteliadis, Pavlos; John, Astrid; Jedynska, Aleksandra; Kuhlbusch, Thomas A J; Putaud, Jean-Philippe; Karanasiou, Angeliki

    2017-10-18

    The European Committee for Standardisation (CEN) Technical Committee 264 'Air Quality' has recently produced a standard method for the measurements of organic carbon and elemental carbon in PM 2.5 within its working group 35 in response to the requirements of European Directive 2008/50/EC. It is expected that this method will be used in future by all Member States making measurements of the carbonaceous content of PM 2.5 . This paper details the results of a laboratory and field measurement campaign and the statistical analysis performed to validate the standard method, assess its uncertainty and define its working range to provide clarity and confidence in the underpinning science for future users of the method. The statistical analysis showed that the expanded combined uncertainty for transmittance protocol measurements of OC, EC and TC is expected to be below 25%, at the 95% level of confidence, above filter loadings of 2 μg cm -2 . An estimation of the detection limit of the method for total carbon was 2 μg cm -2 . As a result of the laboratory and field measurement campaign the EUSAAR2 transmittance measurement protocol was chosen as the basis of the standard method EN 16909:2017.

  3. Simultaneous Multi-Element Electrothermal Atomic Absorption ...

    African Journals Online (AJOL)

    width of transmittance profile 120 pm, a linear CCD array attached to a PC and a tube atomizer furnished with a carbon fibre collector. In the experiments simultaneous determination of 18 elements was performed in the mixed solutions at the mg ...

  4. X-ray microprobe measurements of the chemical compositions of ALH84001 carbonate globules

    International Nuclear Information System (INIS)

    Flynn, G.J.; Sutton, S.R.; Keller, L.P.

    2004-01-01

    We measured minor element contents of carbonate from ALH84001 and report trends in tbe Ca, V, Mn and Sr in carbonate and the associated magnetite bands. McKay et al. suggested that carbonate globules in the ALH84001 meteorite from Mars contained evidence consistent with the development of bacterial life early in the history of Mars. This result provoked an extensive study of the ALH84001 meteorite. More recently Thomas-Keprta et al. have published a study showing that the magnetite associated with carbonate rims are of the size and shape produced by terrestrial bacteria. This paper has revived interest in ALH84001. The typical ALH84001 carbonate globule consists of four regions: a core of Fe-rich carbonate, a thin magnetite-rich band, a rim of Mn-rich carbonate, and another thin magnetite-rich band. Trace element analysis of each of these phases may allow us to address several important questions about these carbonates: (1) The origin of the magnetite-rich bands in the ALH84001 carbonate globules. If the magnetites are derived from the underlying carbonate through thermal decomposition (as proposed by Golden et al.), then we expect to see 'inherited' trace elements in these magnetite bands. (2) The origin of the rim carbonate, by determining whether the carbonate in the core has the same trace elements as the rim carbonates. (3) The age of the rim carbonate. Borg et al. dated the formation of the rim carbonate using the Rb/Sr chronometer. Borg et al. performed their measurements on an aliquot of what they called a high-Rb, low-Sr carbonate separate from the rim. We previously measured the trace element contents of chips from core and rim carbonates from an ALH84001 carbonate globule using an X-Ray Microprobe on Beamline X26A at the National Synchrotron Light Source. These measurements showed the rim carbonate had a very low Rb content, with Sr>>Rb, inconsistent with the ∼5 ppm Rb reported by Borg et al. in the sample they dated by the Rb/Sr chronometer. The large

  5. Are carbon credits effective?

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    Is it possible to reduce greenhouse gas emissions by assigning a value to CO 2 ? That's the concept behind carbon credits. Their advantage: they set targets but let companies decide how to meet them. Of all the processes that can be used to reduce air pollution, the cap and trade system is the best way to meet global targets on a national or continental scale. The system's efficiency is based on setting a ceiling for emissions: this is the cap. The emissions quotas are negotiable goods that can be traded on a market: this is the 'trade'. No company can exceed its quotas, but it can choose how to meet them: decreasing its emissions by changing its production processes, buying carbon credits sold by companies that have exceeded their targets, or using clean development mechanisms. For a carbon credit system to function correctly on an economic level, it's essential to meet one condition: don't allocate too many emissions quotas to the companies involved. If they receive too many quotas, it's not hard for them to meet their objectives without changing their production processes. The supply of carbon credits currently exceeds demand. The price per ton of CO 2 is collapsing, and companies that have exceeded their targets are not rewarded for their efforts. Efficient though it may be, the cap and trade system cannot be the only way to fight CO 2 emissions. In Europe, it presently covers 40% of the CO 2 emissions by targeting utilities and industries that consume the most fossil fuels. But it cannot be extended to some sectors where pollution is diffuse. In transportation, for example, it's not possible to impose such a requirement. For that sector, as well as for the building sector, a suitable system of taxes might be effective and incentive

  6. Investigating Low-Carbon City: Empirical Study of Shanghai

    Directory of Open Access Journals (Sweden)

    Xuan Yang

    2018-04-01

    Full Text Available A low-carbon economy is an inevitable choice for achieving economic and ecological sustainable development. It is of significant importance to analyze a city’s low-carbon economy development level scientifically and reasonably. In order to achieve this goal, we propose an urban low-carbon economic development level evaluation model based on the matter-element extension method. First, we select some indicators from the existing indicator system based on past research and experience. Then, a matter-element model is established on the basis of weight to evaluate the level of a city’s low-carbon, the critical value of each index is determined through the classical domain and the section domain, calculating the correlation degree of a single index and a comprehensive index. Finally, we analyze the low-carbon economy development status and future development trends according to the analysis results. In this study, we select Shanghai as an empirical study—the results show that Shanghai is a city with a low-carbon level and there is a trend of further improvement in Shanghai’s low-carbon economy. But its low carbon construction and low carbon technology investment are relatively low. In summary, this method can provide another angle for evaluating a city’s low-carbon economy.

  7. Solid-phase reversible trap for [ sup 1 sup 1 C]carbon dioxide using carbon molecular sieves

    CERN Document Server

    Mock, B H; Mulholland, G T

    1995-01-01

    A simple, maintenance-free trapping technique which concentrates and purifies no-carrier-added sup 1 sup 1 CO sub 2 from gas targets is described. The trap requires no liquid nitrogen cooling and has no moving parts besides solenoid valves. It employs carbon molecular sieves to adsorb sup 1 sup 1 CO sub 2 selectively from gas targets at room temperature. Nitrogen, O sub 2 , CO, NO and moisture in the target gas which could interfere with subsequent radiochemical steps are not retained. Trapping efficiency of 1 g of sieve for sup 1 sup 1 CO sub 2 from a 240 cm sup 3 target gas dump and helium flush cycle is <99%, and the adsorbed sup 1 sup 1 CO sub 2 is recovered quantitatively as a small concentrated bolus from the carbon sieve trap by thermal desorption. This durable trap has performed reliably for more than 1 y with a single charge of carbon sieve. It has simplified the production, and improved the yields of several sup 1 sup 1 C-radiochemicals at this laboratory.

  8. Target selection for direct marketing.

    NARCIS (Netherlands)

    Bult, Jan Roelf

    1993-01-01

    In this thesis we concentrated on the use ol direct mail for targeting potential buyers. The major characteristics that influences the success of a plomotional direct mail campaign are the of-fbr,the communication elements, the timing or sequence of these communication elements, and the list of

  9. Sensitive targeted multiple protein quantification based on elemental detection of Quantum Dots

    Energy Technology Data Exchange (ETDEWEB)

    Montoro Bustos, Antonio R.; Garcia-Cortes, Marta [Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería 8, Oviedo 33006 (Spain); González-Iglesias, Hector [Fundación de Investigación Oftalmológica, Instituto Oftalmológico Fernandez-Vega, Avenida Doctores Fernández-Vega, 34, Oviedo 33012 (Spain); Ruiz Encinar, Jorge, E-mail: ruizjorge@uniovi.es [Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería 8, Oviedo 33006 (Spain); Costa-Fernández, José M. [Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería 8, Oviedo 33006 (Spain); Coca-Prados, Miguel [Fundación de Investigación Oftalmológica, Instituto Oftalmológico Fernandez-Vega, Avenida Doctores Fernández-Vega, 34, Oviedo 33012 (Spain); Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT 06510 (United States); Sanz-Medel, Alfredo, E-mail: asm@uniovi.es [Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería 8, Oviedo 33006 (Spain)

    2015-06-16

    Highlights: • Novel generic platform for multiparametric quantification of proteins. • QDs labeling and ICP-MS detection allow significant analytical signal amplification. • ICP-MS mass balances information provided an internal validation of the immunoassay. • Multiparametric determination of 5 proteins in human serum samples. • ICP-MS reduced matrix effects as compared to other conventional detection techniques. - Abstract: A generic strategy based on the use of CdSe/ZnS Quantum Dots (QDs) as elemental labels for protein quantification, using immunoassays with elemental mass spectrometry (ICP-MS), detection is presented. In this strategy, streptavidin modified QDs (QDs-SA) are bioconjugated to a biotinylated secondary antibody (b-Ab{sub 2}). After a multi-technique characterization of the synthesized generic platform (QDs-SA-b-Ab{sub 2}) it was applied to the sequential quantification of five proteins (transferrin, complement C3, apolipoprotein A1, transthyretin and apolipoprotein A4) at different concentration levels in human serum samples. It is shown how this generic strategy does only require the appropriate unlabeled primary antibody for each protein to be detected. Therefore, it introduces a way out to the need for the cumbersome and specific bioconjugation of the QDs to the corresponding specific recognition antibody for every target analyte (protein). Results obtained were validated with those obtained using UV–vis spectrophotometry and commercial ELISA Kits. As expected, ICP-MS offered one order of magnitude lower DL (0.23 fmol absolute for transferrin) than the classical spectrophotometric detection (3.2 fmol absolute). ICP-MS precision and detection limits, however turned out to be compromised by procedural blanks. The full analytical performance of the ICP-MS-based immunoassay proposed was assessed for detection of transferrin (Tf), present at the low ng mL{sup −1} range in a complex “model” synthetic matrix, where the total protein

  10. 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

  11. Effect of carbon fiber dispersion on the mechanical properties of carbon fiber-reinforced cement-based composites

    International Nuclear Information System (INIS)

    Wang Chuang; Li Kezhi; Li Hejun; Jiao Gengsheng; Lu Jinhua; Hou Dangshe

    2008-01-01

    The preparation of carbon fiber-reinforced cement-based composites involved two-step dispersions of carbon fibers. Both steps affected greatly the mechanical properties of the composites. With the aid of ultrasonic wave, a new dispersant hydroxyethyl cellulose was used to help fiber dispersion in the first step. The fracture surface of the composites was observed by scanning electron microscopy. The distribution of major elements was analyzed by the energy dispersive spectroscopy and the composition was analyzed through X-ray diffraction. The flexural strength, tensile strength, modulus, and compression strength were measured. Results showed that the distribution of major elements varied with the variation of the fiber dispersion status. The compressive strength increased by 20%, the tensile strength was 2.4 times that of the material without carbon fibers, the modulus increased by 26.8%, whereas the flexure stress decreased by 12.9%

  12. Fixation Of Mo In Uranium Leach Liquor By Activated Carbon

    International Nuclear Information System (INIS)

    Mainar, S.; Guswita, A.; Erni, R.A.; Susilaningtyas

    1996-01-01

    The use of activated carbon for Mo fixation by bulk system is reported. Several factors influencing the fixation process were examined, including contact time, carbon particle size, carbon porosity and the effect of other elements present in Mo containing solutions. Experimental data showed that an adsorption equilibrium of Mo on of activated carbon and 0,85 to 1,18 mm of carbon particle size under forced-convection mass transfer in 100 ml solution that contains + 0,56 m mol of Mo and +. 0,25 m mol Of U was reached after 6 hours period. Under those conditions, about 0,50 m mol of Mo and 0,026 m mol of U were adsorbed into carbon. High concentration of rare earth elements decreased Mo adsorption, hence, the use of activated carbon was not effective to separate Mo from the digestion liquor of Rirang are where Mo was adsorbed, into the carbon + 34,5 %

  13. Emission factors of fine particulate matter, organic and elemental carbon, carbon monoxide, and carbon dioxide for four solid fuels commonly used in residential heating by the U.S. Navajo Nation.

    Science.gov (United States)

    Champion, Wyatt M; Connors, Lea; Montoya, Lupita D

    2017-09-01

    Most homes in the Navajo Nation use wood as their primary heating fuel, often in combination with locally mined coal. Previous studies observed health effects linked to this solid-fuel use in several Navajo communities. Emission factors (EFs) for common fuels used by the Navajo have not been reported using a relevant stove type. In this study, two softwoods (ponderosa pine and Utah juniper) and two high-volatile bituminous coals (Black Mesa and Fruitland) were tested with an in-use residential conventional wood stove (homestove) using a modified American Society for Testing and Materials/U.S. Environmental Protection Agency (ASTM/EPA) protocol. Filter sampling quantified PM 2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) and organic (OC) and elemental (EC) carbon in the emissions. Real-time monitoring quantified carbon monoxide (CO), carbon dioxide (CO 2 ), and total suspended particles (TSP). EFs for these air pollutants were developed and normalized to both fuel mass and energy consumed. In general, coal had significantly higher mass EFs than wood for all pollutants studied. In particular, coal emitted, on average, 10 times more PM 2.5 than wood on a mass basis, and 2.4 times more on an energy basis. The EFs developed here were based on fuel types, stove design, and operating protocols relevant to the Navajo Nation, but they could be useful to other Native Nations with similar practices, such as the nearby Hopi Nation. Indoor wood and coal combustion is an important contributor to public health burdens in the Navajo Nation. Currently, there exist no emission factors representative of Navajo homestoves, fuels, and practices. This study developed emission factors for PM 2.5 , OC, EC, CO, and CO 2 using a representative Navajo homestove. These emission factors may be utilized in regional-, national-, and global-scale health and environmental models. Additionally, the protocols developed and results presented here may inform on-going stove design of

  14. Japanese citizens’ preferences regarding voluntary carbon offsets: an experimental social survey of Yokohama and Kitakyushu

    International Nuclear Information System (INIS)

    Nakamura, Hidenori; Kato, Takaaki

    2013-01-01

    This study uses an experimental social survey in two large Japanese cities to explore citizens’ attitudes toward international voluntary carbon offsetting that encourages low carbon development in developing countries. In particular, the study focuses on whether the offsetting is a contribution to meet national target of greenhouse gas (GHG) emissions reduction under the Kyoto Protocol or reduction beyond the national target, using Kyoto credits generated from climate change mitigation projects in developing countries. The study finds that around 40% of the survey respondents chose real carbon offsetting over a gift certificate as compensation for their participation in the survey, around half of whom chose carbon offsetting contribution to the world. However, most of the current Japanese carbon offsetting providers utilise only the carbon offsetting contribution to the Japanese government. Thus, Japanese citizens have significant untapped potential for undertaking more carbon offsetting to meet targets other than national targets. However, the results also show that there is a general lack of understanding regarding the mechanism of carbon offsetting. Carbon offsetting providers in Japan and other countries that may have national self-imposed targets and allowing the usage of international carbon offsetting should therefore be considered, so as to provide individuals with the options of either contributing to their government to help it meet its national target or contributing to the world to help reduce GHG emissions beyond the national targets.

  15. Carbon Ion Therapy

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, David Christoffer; Herrmann, Rochus

    On the importance of choice of target size for selective boosting of hypoxic tumor subvolumina in carbon ion therapy Purpose: Functional imaging methods in radiotherapy are maturing and can to some extent uncover radio resistant structures found within a tumour entity. Selective boost of identified...... effect. All cell lines investigated here did not reach an OER of 1, even for the smaller structures, which may indicate that the achievable dose average LET of carbon ions is too low, and heavier ions than carbon may be considered for functional LET-painting....

  16. Opinion of the committee of experts for energy transition on the national low-carbon strategy (SNBC)

    International Nuclear Information System (INIS)

    Colombier, Michel

    2015-01-01

    Whereas the French 'national low carbon strategy' (French acronym: SNBC) is a major element governance for a transition towards a low-carbon society, and is thus supposed to define targeted objectives and privileged directions, this document proposes an analysis of directions defined within the law on energy transition for a green growth, discusses carbon budgets to be respected for the different intermediate periods, and proposes a follow-up and assessment framework. Moreover, through this document, the Committee first states a set of recommendations which are able to be integrated into the next SNBC version: general directions for the next SNBC, recommendations for the transverse part of the strategy and for its sector-based part, and briefly for the elaboration and consultation process. Then, another set of recommendations is discussed. These recommendations address the SNBC follow-up and assessment: definitions of different indicators, economic assessment, social-economic assessment, and environmental and health assessment. Finally, some proposals are made for the writers about the SNBC

  17. Synthesis and properties of superheavy elements

    CERN Document Server

    Hofmann, S

    2003-01-01

    The nuclear shell model predicts that the next doubly magic shell-closure beyond sup 2 sup 0 sup 8 Pb is at a proton number Z = 114, 120, or 126 and at a neutron number N = 172 or 184. The outstanding of experimental investigations is the exploration of this region of spherical 'SuperHeavy Elements' (SHEs). Experimental methods are described which allowed for the identification of elements 107 to 112 in studies of cold fusion reactions based on lead and bismuth targets. Also presented are data which were obtained on the synthesis of elements 112, 114, and 116 in investigation of hot fusion reactions using actinide targets. The decay data reveal that for the heaviest elements, the dominant decay mode is alpha emission, not fission. Decay properties as well as reaction cross- sections are compared with the results of theoretical studies. Finally, plans are presented for the further development of the experimental set-up and the application of new techniques. At a higher sensitivity, the exploration of the regio...

  18. Chemical analysis of the elements in UZrNb alloy at CDTN: preliminary investigation

    International Nuclear Information System (INIS)

    Ferraz, Wilmar Barbosa; Palmieri, Helena Eugenia L.; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos; Souza, Adalberto Leles de

    2012-01-01

    The complete determination of major, minor, and impurity element contents in nuclear fuel is essential for quality assurance in the production of nuclear fuels. The control over all the stages of the development of nuclear fuel involves a combination of different analytical methods such as spectrometric methods. The goal of our investigation is to develop and evaluate procedures for the determination of main elements and carbon impurity present in some uranium alloys. In this paper the element contents in U2.5Zr7.5Nb, U3Zr9Nb alloys and U6Nb, in weight percent, were investigated by means of scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), inductively coupled plasma mass spectrometry (ICP-MS), wavelength dispersive fluorescence spectrometry (XRF/WDS) and energy-dispersive X-ray spectroscopy (EDX). The total carbon was determined using a carbon analyzer in which the sample is oxidized to carbon dioxide (IR absorption). It was observed a satisfactory correlation between the results obtained by employed methods. (author)

  19. Lightning-produced Carbon Species in the Atmosphere of Saturn

    Science.gov (United States)

    Delitsky, Mona; Baines, K. H.

    2010-10-01

    Recent studies by Baines et al (2009) indicate that thunderstorm-associated clouds on Saturn are spectrally dark from 0.7 to 4 um, darker than regular clouds. This darkening is found to be consistent with the presence of particles of elemental carbon, such as in the form of soot particles mixed in with spectrally bright condensates. This carbon is thought to be generated by lightning-induced dissociation of methane. Lightning on Saturn will input large amounts of energy to a narrow column of atmosphere and generate products at high energies such as radicals and ions. After the column cools down, the new chemical species recombine and are frozen into a new chemical equilibrium. Experimental studies in the literature of reactions of methane and other gases in plasma discharges (which simulate lightning) indicate that, even with high ratios of hydrogen/methane, the elemental carbon obtained will form solid dark particles that persist and have a very high C/H ratio. Basically, they are mostly pure carbon, in the form of soot, amorphous carbon, graphite, graphene, polycyclic aromatic hydrocarbons, carbon black, carbon onions, etc. Hydrogen will act as a sealant onto the particles and attach to dangling bonds on their growing surfaces. Even in experiments to form the most crystalline allotrope of carbon, that is, diamond, the presence of hydrogen does not inhibit diamond formation, even at the low pressures in the atmospheres of the Jovian planets or in the interstellar medium (Allamandola et al 1991). Therefore, some form of elemental carbon is likely produced in Saturnian storm clouds and may occur as dark particles of either amorphous carbon, PAHs or crystalline carbon in a form such as graphite. ..Refs: Baines et al., PSS 57, 1650-1658 (2009) ; Allamandola et al., Meteoritics 26, 313 (1991).

  20. LIGHT-ELEMENT ABUNDANCE VARIATIONS AT LOW METALLICITY: THE GLOBULAR CLUSTER NGC 5466

    International Nuclear Information System (INIS)

    Shetrone, Matthew; Martell, Sarah L.; Wilkerson, Rachel; Adams, Joshua; Siegel, Michael H.; Smith, Graeme H.; Bond, Howard E.

    2010-01-01

    We present low-resolution (R ≅850) spectra for 67 asymptotic giant branch (AGB), horizontal branch, and red giant branch (RGB) stars in the low-metallicity globular cluster NGC 5466, taken with the VIRUS-P integral-field spectrograph at the 2.7 m Harlan J. Smith telescope at McDonald Observatory. Sixty-six stars are confirmed, and one rejected, as cluster members based on radial velocity, which we measure to an accuracy of 16 km s -1 via template-matching techniques. CN and CH band strengths have been measured for 29 RGB and AGB stars in NGC 5466, and the band-strength indices measured from VIRUS-P data show close agreement with those measured from Keck/LRIS spectra previously taken for five of our target stars. We also determine carbon abundances from comparisons with synthetic spectra. The RGB stars in our data set cover a range in absolute V magnitude from +2 to -3, which permits us to study the rate of carbon depletion on the giant branch as well as the point of its onset. The data show a clear decline in carbon abundance with rising luminosity above the luminosity function 'bump' on the giant branch, and also a subdued range in CN band strength, suggesting ongoing internal mixing in individual stars but minor or no primordial star-to-star variation in light-element abundances.

  1. Nuclear Targets for a Precision Measurement of the Neutral Pion Radiative Width

    International Nuclear Information System (INIS)

    Martel, Philippe; Clinton, Eric; McWilliams, R.; Lawrence, Dave; Miskimen, Rory; Ahmidouch, Abdellah; Ambrozewicz, Pawel; Asaturyan, Arshak; Baker, O.; Benton, LaRay; Bernstein, Aron; Cole, Philip; Collins, Patrick; Dale, Daniel; Danagoulian, Samuel; Davidenko, G.; Demirchyan, Raphael; Deur, Alexandre; Dolgolenko, A.; Dzyubenko, Georgiy; Evdokimov, Anatoly; Feng, JIng; Gabrielyan, Marianna; Gan, Liping; Gasparian, Ashot; Glamazdin, Oleksandr; Goryachev, Vladimir; Gyurjyan, Vardan; Hardy, K.; Ito, Mark; Khandaker, Mahbubul; Kingsberry, Paul; Kolarkar, Ameya; Konchatnyi, Mykhailo; Korchin, O.; Korsch, Wolfgang; Kowalski, Stanley; Kubantsev, Mikhail; Kubarovsky, Valery; Larin, Ilya; Matveev, V.; McNulty, Dustin; Milbrath, Brian; Minehart, Ralph; Mochalov, Vasiliy; Mtingwa, Sekazi; Nakagawa, Itaru; Overby, Steven; Pasyuk, Evgueni; Payen, Marvin; Pedroni, Ronald; Prok, Yelena; Ritchie, Barry; Salgado, Carlos; Sitnikov, Anatoly; Sober, Daniel; Stephens, W.; Teymurazyan, Aram; Underwood, Jarreas; Vasiliev, A.; Verebryusov, V.; Vishnyakov, Vladimir; Wood, Michael

    2009-01-01

    A technique is presented for precision measurements of the area densities, density * T, of approximately 5% radiation length carbon and 208Pb targets used in an experiment at Jefferson Laboratory to measure the neutral pion radiative width. The precision obtained in the area density for the carbon target is +/- 0.050%, and that obtained for the lead target through an x-ray attenuation technique is +/- 0.43%.

  2. Organic, elemental and inorganic carbon in particulate matter of six urban environments in Europe

    Directory of Open Access Journals (Sweden)

    M. Sillanpää

    2005-01-01

    Full Text Available A series of 7-week sampling campaigns were conducted in urban background sites of six European cities as follows: Duisburg (autumn, Prague (winter, Amsterdam (winter, Helsinki (spring, Barcelona (spring and Athens (summer. The campaigns were scheduled to include seasons of local public health concern due to high particulate concentrations or findings in previously conducted epidemiological studies. Aerosol samples were collected in parallel with two identical virtual impactors that divide air particles into fine (PM2.5 and coarse (PM2.5-10 size ranges. From the collected filter samples, elemental (EC and organic (OC carbon contents were analysed with a thermal-optical carbon analyser (TOA; total Ca, Ti, Fe, Si, Al and K by energy dispersive X-ray fluorescence (ED-XRF; As, Cu, Ni, V, and Zn by inductively coupled plasma mass spectrometry (ICP/MS; Ca2+, succinate, malonate and oxalate by ion chromatography (IC; and the sum of levoglucosan+galactosan+mannosan (∑MA by liquid chromatography mass spectrometry (LC/MS. The campaign means of PM2.5 and PM2.5-10 were 8.3-29.6 µg m-3 and 5.4-28.7 µg m-3, respectively. The contribution of particulate organic matter (POM to PM2.5 ranged from 21% in Barcelona to 54% in Prague, while that to PM2.5-10 ranged from 10% in Barcelona to 27% in Prague. The contribution of EC was higher to PM2.5 (5-9% than to PM2.5-10 (1-6% in all the six campaigns. Carbonate (C(CO3, that interferes with the TOA analysis, was detected in PM2.5-10 of Athens and Barcelona but not elsewhere. It was subtracted from the OC by a simple integration method that was validated. The CaCO3 accounted for 55% and 11% of PM2.5-10 in Athens and Barcelona, respectively. It was anticipated that combustion emissions from vehicle engines affected the POM content in PM2.5 of all the six sampling campaigns, but a comparison of mass concentration ratios of the selected inorganic and organic tracers of common sources of organic material to POM suggested

  3. Transition between laser absorption dominated regimes in carbon-based plasma

    Directory of Open Access Journals (Sweden)

    K. Hajisharifi

    2017-09-01

    Full Text Available In this work, we investigate the energy absorption enhancement of a laser by adding a variety of light ion species to a primarily carbon-based plasma during the high-power laser interaction with the finite size targets. A developed Particle-In-Cell simulation code is used to study the reduction of laser reflectivity (stimulated backward scatterings in both Brillouin- and Raman-dominated regimes. The simulation is performed in various Carbon-light ion plasmas such as Carbon-Hydrogen, Carbon-Helium, Carbon-Deuterium, and Carbon-Tritium. The results show that, in the optimized condition, the inclusion of light Hydrogen ions into the Carbon-based plasma up to 50%-50% mixture enhances the laser absorption exceeding 20% in the Brillouin regime due to the suppression of laser reflectivity in contract to 4% in the Raman-dominated regime. Moreover, the absorption dominated regime switches from Raman to Brillouin regime by adding 50% of Hydrogen ions to a purely carbon target. The results of this investigation will be applicable to the laser-plasma experiments so long as the laser energy absorption in the Carbon plasma target, the most readily available material in laboratory, is concerned.

  4. New elements - approaching Z=114

    International Nuclear Information System (INIS)

    Hofmann, S.

    1998-03-01

    The search for new elements is part of the broader field of investigations of nuclei at the limits of stability. In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using 1n-deexcitation channels and lead or bismuth targets. The isotopes were unambiguously identified by means of α-α correlations. Not fission, but alpha decay is the dominant decay mode. The collected decay data establish a means of comparison with theoretical data. This aids in the selection of appropriate models that describe the properties of known nuclei. Predictions based on these models are useful in the preparation of the next generation of experiments. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. The development of intense beam currents and sensitive detection methods is essential for the production and identification of still heavier elements and new isotopes of already known elements, as well as the measurement of small α-, β- and fission-branching ratios. An equally sensitive set-up is needed for the measurement of excitation functions at low cross-sections. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical super heavy elements (SHE) could be achieved by fusion reactions using 208 Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. (orig.)

  5. Determination of trace elements in calcite using solution and laser ablation ICP-MS: calibration to NIST SRM glass and USGS MACS carbonate, and application to real landfill calcite

    Czech Academy of Sciences Publication Activity Database

    Strnad, L.; Ettler, V.; Mihaljevič, M.; Hladil, Jindřich; Chrastný, V.

    2009-01-01

    Roč. 33, č. 3 (2009), s. 347-355 ISSN 1639-4488 R&D Projects: GA AV ČR IAA300130702 Institutional research plan: CEZ:AV0Z30130516 Keywords : trace elements * carbonate * reference material * MACS-1 MACS-2 * laser ablation ICP-MS Subject RIV: DD - Geochemistry Impact factor: 2.061, year: 2009

  6. Predicting ambient aerosol Thermal Optical Reflectance (TOR) measurements from infrared spectra: elemental carbon

    Science.gov (United States)

    Dillner, A. M.; Takahama, S.

    2015-06-01

    Elemental carbon (EC) is an important constituent of atmospheric particulate matter because it absorbs solar radiation influencing climate and visibility and it adversely affects human health. The EC measured by thermal methods such as Thermal-Optical Reflectance (TOR) is operationally defined as the carbon that volatilizes from quartz filter samples at elevated temperatures in the presence of oxygen. Here, methods are presented to accurately predict TOR EC using Fourier Transform Infrared (FT-IR) absorbance spectra from atmospheric particulate matter collected on polytetrafluoroethylene (PTFE or Teflon) filters. This method is similar to the procedure tested and developed for OC in prior work (Dillner and Takahama, 2015). Transmittance FT-IR analysis is rapid, inexpensive, and non-destructive to the PTFE filter samples which are routinely collected for mass and elemental analysis in monitoring networks. FT-IR absorbance spectra are obtained from 794 filter samples from seven Interagency Monitoring of PROtected Visual Environment (IMPROVE) sites collected during 2011. Partial least squares regression is used to calibrate sample FT-IR absorbance spectra to collocated TOR EC measurements. The FTIR spectra are divided into calibration and test sets. Two calibrations are developed, one which is developed from uniform distribution of samples across the EC mass range (Uniform EC) and one developed from a~uniform distribution of low EC mass samples (EC < 2.4 μg, Low Uniform EC). A hybrid approach which applies the low EC calibration to low EC samples and the Uniform EC calibration to all other samples is used to produces predictions for low EC samples that have mean error on par with parallel TOR EC samples in the same mass range and an estimate of the minimum detection limit (MDL) that is on par with TOR EC MDL. For all samples, this hybrid approach leads to precise and accurate TOR EC predictions by FT-IR as indicated by high coefficient of variation (R2; 0.96), no

  7. 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.

  8. The feasibility of low concentration targets: An application of FUND

    International Nuclear Information System (INIS)

    Tol, Richard S.J.

    2009-01-01

    This paper studies the feasibility of stringent targets for stabilizing ambient greenhouse gas concentrations using the FUND model. 170,000 policy scenarios were run, systematically varying the price of carbon, participation in climate policy, the strength of the climate feedback on the terrestrial carbon cycle, the no policy scenario, and the abatement costs. The results reveal the following. Climate policy has diminishing returns, and there is therefore a maximum to what can be achieved. The success of climate policy is hampered if, as is likely, the terrestrial biosphere turns from a carbon sink to a carbon source because of climate change. All major countries have to reduce their emissions in order to meet the more ambitious stabilization targets. The cost of climate policy would be lower if the stabilization target can be exceeded in the interim. The EU target of 2 deg. C warming above pre-industrial is infeasible under almost all assumptions. A cost-benefit analysis would endorse a target of 4.5 W m -2 (but not much stricter than that) if all major emitters engage in abatement. Under the same condition, the median US voter would support a 3.7 W m -2 target (but not much stricter than that). International permit trade would encourage large developing countries to reduce their emissions, but the trade flows would be substantial relative to product trade and much larger than official development aid.

  9. Eelectrochemical properties and corrosion resistance of carbon-ion-implanted magnesium

    International Nuclear Information System (INIS)

    Xu, Ruizhen; Yang, Xiongbo; Li, Penghui; Suen, Kai Wong; Wu, Guosong; Chu, Paul K.

    2014-01-01

    Highlights: • Carbon, as a biocompatible benign element, was implanted into Mg. • A protective amorphous carbon layer was formed after implantation. • Treated sample exhibits good corrosion resistance in two solutions. - Abstract: The corrosion resistance of magnesium-based biomaterials is critical to clinical applications. In this work, carbon as a biocompatible and benign nonmetallic element with high chemical inertness is implanted into pure magnesium to improve the corrosion behavior. X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), and Raman scattering reveal the formation of an amorphous carbon layer after ion implantation. Electrochemical studies demonstrate remarkable improvement in the corrosion resistance of magnesium in simulated body fluids (SBF) and Dulbecco’s Modified Eagle Medium (DMEM)

  10. Mars Target Encyclopedia: Information Extraction for Planetary Science

    Science.gov (United States)

    Wagstaff, K. L.; Francis, R.; Gowda, T.; Lu, Y.; Riloff, E.; Singh, K.

    2017-06-01

    Mars surface targets / and published compositions / Seek and ye will find. We used text mining methods to extract information from LPSC abstracts about the composition of Mars surface targets. Users can search by element, mineral, or target.

  11. Structure of a conjugative element in Streptococcus pneumoniae

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, M.N.; Priebe, S.D.; Guild, W.R.

    1986-06-01

    The authors have cloned and mapped a 69-kilobase (kb) region of the chromosome of Streptococcus pneumoniae DP1322, which carries the conjugative Omega(cat-tet) insertion from S. pneumoniae BM6001. This element proved to be 65.5 kb in size. Location of the junctions was facilitated by cloning a preferred target region from the wild-type strain Rx1 recipient genome. This target site was preferred by both the BM6001 element and the cat-erm-tet element from Streptococcus agalactiae B109. Within the BM6001 element cat and tet were separated by 30 kb, and cat was flanked by two copies of a sequence that was also present in the recipient strain Rx1 DNA. Another sequence at least 2.4 kb in size was found inside the BM6001 element and at two places in the Rx1 genome. Its role is unknown. The ends of the BM6001 element appear to be the same as those of the B109 element, both as seen after transfer to S. pneumoniae and as mapped by others in pDP5 after transposition in Streptococcus faecalis. No homology is seen between the ends of the BM6001 element and no evidence found suggesting that it ever circularizes.

  12. Synthesis of neutron-rich transuranic nuclei in fissile spallation targets

    Energy Technology Data Exchange (ETDEWEB)

    Mishustin, Igor, E-mail: mishustin@fias.uni-frankfurt.de [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); “Kurchatov Institute”, National Research Center, 123182 Moscow (Russian Federation); Malyshkin, Yury, E-mail: malyshkin@fias.uni-frankfurt.de [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow (Russian Federation); Pshenichnov, Igor, E-mail: pshenich@fias.uni-frankfurt.de [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow (Russian Federation); Greiner, Walter [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany)

    2015-04-15

    A possibility of synthesizing neutron-rich superheavy elements in spallation targets of Accelerator Driven Systems (ADS) is considered. A dedicated software called Nuclide Composition Dynamics (NuCoD) was developed to model the evolution of isotope composition in the targets during a long-time irradiation by intense proton and deuteron beams. Simulation results show that transuranic elements up to {sup 249}Bk can be produced in multiple neutron capture reactions in macroscopic quantities. However, the neutron flux achievable in a spallation target is still insufficient to overcome the so-called fermium gap. Further optimization of the target design, in particular, by including moderating material and covering it by a reflector could turn ADS into an alternative source of transuranic elements in addition to nuclear fission reactors.

  13. Processing and Structure of Carbon Nanofiber Paper

    Directory of Open Access Journals (Sweden)

    Zhongfu Zhao

    2009-01-01

    Full Text Available A unique concept of making nanocomposites from carbon nanofiber paper was explored in this study. The essential element of this method was to design and manufacture carbon nanofiber paper with well-controlled and optimized network structure of carbon nanofibers. In this study, carbon nanofiber paper was prepared under various processing conditions, including different types of carbon nanofibers, solvents, dispersants, and acid treatment. The morphologies of carbon nanofibers within the nanofiber paper were characterized with scanning electron microscopy (SEM. In addition, the bulk densities of carbon nanofiber papers were measured. It was found that the densities and network structures of carbon nanofiber paper correlated to the dispersion quality of carbon nanofibers within the paper, which was significantly affected by papermaking process conditions.

  14. Introducing carbon taxes in South Africa

    International Nuclear Information System (INIS)

    Alton, Theresa; Arndt, Channing; Davies, Rob; Hartley, Faaiqa; Makrelov, Konstantin; Thurlow, James; Ubogu, Dumebi

    2014-01-01

    Highlights: • South Africa is considering introducing a carbon tax to reduce greenhouse gas emissions. • A phased-in tax of US$30 per ton can achieve national emissions reductions targets set for 2025. • Ignoring all potential benefits, the tax reduces national welfare by about 1.2 percent in 2025. • Border carbon adjustments reduce welfare losses while maintaining emissions reductions. • The mode for recycling carbon tax revenues strongly influences distributional outcomes. - Abstract: South Africa is considering introducing a carbon tax to reduce greenhouse gas emissions. Following a discussion of the motivations for considering a carbon tax, we evaluate potential impacts using a dynamic economywide model linked to an energy sector model including a detailed evaluation of border carbon adjustments. Results indicate that a phased-in carbon tax of US$30 per ton of CO 2 can achieve national emissions reductions targets set for 2025. Relative to a baseline with free disposal of CO 2 , constant world prices and no change in trading partner behavior, the preferred tax scenario reduces national welfare and employment by about 1.2 and 0.6 percent, respectively. However, if trading partners unilaterally impose a carbon consumption tax on South African exports, then welfare/employment losses exceed those from a domestic carbon tax. South Africa can lessen welfare/employment losses by introducing its own border carbon adjustments. The mode for recycling carbon tax revenues strongly influences distributional outcomes, with tradeoffs between growth and equity

  15. Thermal characteristics of carbon fiber reinforced epoxy containing multi-walled carbon nanotubes

    Science.gov (United States)

    Lee, Jin-woo; Park, Soo-Jeong; Kim, Yun-hae; Riichi-Murakami

    2018-06-01

    The material with irregular atomic structures such as polymer material exhibits low thermal conductivity because of the complex structural properties. Even materials with same atomic configurations, thermal conductivity may be different based on their structural properties. It is expected that nanoparticles with conductivity will change non-conductive polymer base materials to electrical conductors, and improve the thermal conductivity even with extremely small filling amount. Nano-composite materials contain nanoparticles with a higher surface ratio which makes the higher interface percentage to the total surface of nanoparticles. Therefore, thermal resistance of the interface becomes a dominating factor determines the effective thermal conductivity in nano-composite materials. Carbon fiber has characteristic of resistance or magnetic induction and Also, Carbon nanotube (CNT) has electronic and thermal property. It can be applied for heating system. These characteristic are used as heating composite. In this research, the exothermic characteristics of Carbon fiber reinforced composite added CNT were evaluated depend on CNT length and particle size. It was found that the CNT dispersed in the resin reduces the resistance between the interfaces due to the decrease in the total resistance of the heating element due to the addition of CNTs. It is expected to improve the life and performance of the carbon fiber composite material as a result of the heating element resulting from this paper.

  16. Temperature simulations for the SPIRAL ISOL target

    International Nuclear Information System (INIS)

    Maunoury, L.; Bajeat, O.; Lichtenthaler, R.; Villari, A.C.C.

    2001-01-01

    Simulations of the power deposition and target temperature distributions in the SPIRAL ISOL target are presented. These simulations consider different heavy-ion beams with intensities corresponding to 2 and 6 kW on a carbon target. A new solutions, which corresponds to the splitting of the production target into two parts, where the first is cooled and the second is heated, allows keeping the overall size of the target ensemble relatively small. An extrapolation of the considered target geometry to primary beam intensities up to 1 MW is also presented. (authors)

  17. The Diesel Exhaust in Miners Study: III. Interrelations between respirable elemental carbon and gaseous and particulate components of diesel exhaust derived from area sampling in underground non-metal mining facilities.

    Science.gov (United States)

    Vermeulen, Roel; Coble, Joseph B; Yereb, Daniel; Lubin, Jay H; Blair, Aaron; Portengen, Lützen; Stewart, Patricia A; Attfield, Michael; Silverman, Debra T

    2010-10-01

    Diesel exhaust (DE) has been implicated as a potential lung carcinogen. However, the exact components of DE that might be involved have not been clearly identified. In the past, nitrogen oxides (NO(x)) and carbon oxides (CO(x)) were measured most frequently to estimate DE, but since the 1990s, the most commonly accepted surrogate for DE has been elemental carbon (EC). We developed quantitative estimates of historical exposure levels of respirable elemental carbon (REC) for an epidemiologic study of mortality, particularly lung cancer, among diesel-exposed miners by back-extrapolating 1998-2001 REC exposure levels using historical measurements of carbon monoxide (CO). The choice of CO was based on the availability of historical measurement data. Here, we evaluated the relationship of REC with CO and other current and historical components of DE from side-by-side area measurements taken in underground operations of seven non-metal mining facilities. The Pearson correlation coefficient of the natural log-transformed (Ln)REC measurements with the Ln(CO) measurements was 0.4. The correlation of REC with the other gaseous, organic carbon (OC), and particulate measurements ranged from 0.3 to 0.8. Factor analyses indicated that the gaseous components, including CO, together with REC, loaded most strongly on a presumed 'Diesel exhaust' factor, while the OC and particulate agents loaded predominantly on other factors. In addition, the relationship between Ln(REC) and Ln(CO) was approximately linear over a wide range of REC concentrations. The fact that CO correlated with REC, loaded on the same factor, and increased linearly in log-log space supported the use of CO in estimating historical exposure levels to DE.

  18. Evaluation of various carbon blacks and dispersing agents for use in the preparation of uranium microspheres with carbon

    Science.gov (United States)

    Hunt, R. D.; Johnson, J. A.; Collins, J. L.; McMurray, J. W.; Reif, T. J.; Brown, D. R.

    2018-01-01

    A comparison study on carbon blacks and dispersing agents was performed to determine their impacts on the final properties of uranium fuel kernels with carbon. The main target compositions in this internal gelation study were 10 and 20 mol % uranium dicarbide (UC2), which is UC1.86, with the balance uranium dioxide. After heat treatment at 1900 K in flowing carbon monoxide in argon for 12 h, the density of the kernels produced using a X-energy proprietary carbon suspension, which is commercially available, ranged from 96% to 100% of theoretical density (TD), with full conversion of UC to UC2 at both carbon concentrations. However, higher carbon concentrations such as a 2.5 mol ratio of carbon to uranium in the feed solutions failed to produce gel spheres with the proprietary carbon suspension. The kernels using our former baseline of Mogul L carbon black and Tamol SN were 90-92% of TD with full conversion of UC to UC2 at a variety of carbon levels. Raven 5000 carbon black and Tamol SN were used to produce 10 mol % UC2 kernels with 95% of TD. However, an increase in the Raven 5000 concentration led to a kernel density below 90% of TD. Raven 3500 carbon black and Tamol SN were used to make very dense kernels without complete conversion to UC2. The selection of the carbon black and dispersing agent is highly dependent on the desired final properties of the target kernels.

  19. Electronic Transmutation (ET): Chemically Turning One Element into Another.

    Science.gov (United States)

    Zhang, Xinxing; Lundell, Katie A; Olson, Jared K; Bowen, Kit H; Boldyrev, Alexander I

    2018-03-08

    The concept of electronic transmutation (ET) depicts the processes that by acquiring an extra electron, an element with the atomic number Z begins to have properties that were known to only belong to its neighboring element with the atomic number Z+1. Based on ET, signature compounds and chemical bonds that are composed of certain elements can now be designed and formed by other electronically transmutated elements. This Minireview summarizes the recent developments and applications of ET on both the theoretical and experimental fronts. Examples on the ET of Group 13 elements into Group 14 elements, Group 14 elements into Group 15 elements, and Group 15 elements into Group 16 elements are discussed. Compounds and chemical bonding composed of carbon, silicon, germanium, phosphorous, oxygen and sulfur now have analogues using transmutated boron, aluminum, gallium, silicon, nitrogen, and phosphorous. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Quantifying sediment source contributions in coastal catchments impacted by the Fukushima nuclear accident with carbon and nitrogen elemental concentrations and stable isotope ratios

    Science.gov (United States)

    Laceby, J. Patrick; Huon Huon, Sylvain; Onda, Yuichi; Evrard, Olivier

    2016-04-01

    The Fukushima Dai-ichi Nuclear Power Plant accidental release of radioactive contaminants resulted in the significant fallout of radiocesium over several coastal catchments in the Fukushima Prefecture. Radiocesium, considered to be the greatest risk to the short and long term health of the local community, is rapidly bound to fine soil particles and thus is mobilized and transported during soil erosion and runoff processes. As there has been a broad-scale decontamination of rice paddy fields and rural residential areas in the contaminated region, one important long term question is whether there is, or may be, a downstream transfer of radiocesium from forests that covered over 65% of the most contaminated region. Accordingly, carbon and nitrogen elemental concentrations and stable isotope ratios are used to determine the relative contributions of forests and rice paddies to transported sediment in three contaminated coastal catchments. Samples were taken from the three main identified sources: cultivated soils (rice paddies and fields, n=30), forest soils (n=45), and subsoils (channel bank and decontaminated soils, n = 25). Lag deposit sediment samples were obtained from five sampling campaigns that targeted the main hydrological events from October 2011 to October 2014. In total, 86 samples of deposited sediment were analyzed for particulate organic matter elemental concentrations and isotope ratios, 24 from the Mano catchment, 44 from the Niida catchment, and 18 from the Ota catchment. Mann-Whitney U-tests were used to examine the source discrimination potential of this tracing suite and select the appropriate tracers for modelling. The discriminant tracers were modelled with a concentration-dependent distribution mixing model. Preliminary results indicate that cultivated sources (predominantly rice paddies) contribute disproportionately more sediment per unit area than forested regions in these contaminated catchments. Future research will examine if there are

  1. Seasonal Cyclicity in Trace Elements and Stable Isotopes of Modern Horse Enamel.

    Science.gov (United States)

    de Winter, Niels J; Snoeck, Christophe; Claeys, Philippe

    2016-01-01

    The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared with trace element profiles measured using laboratory micro X-Ray Fluorescence scanning. Using known patterns of tooth eruption and the relationship between stable oxygen isotopes and local temperature seasonality, an age model is constructed that links records from six cheek upper right teeth from the second premolar to the third molar. When plotted on this age model, the trace element ratios from horse tooth enamel show a seasonal pattern with a small shift in phase compared to stable oxygen isotope ratios. While stable oxygen and carbon isotopes in tooth enamel are forced respectively by the state of the hydrological cycle and the animal's diet, we argue that the seasonal signal in trace elements reflects seasonal changes in dust intake and diet of the animal. The latter explanation is in agreement with seasonal changes observed in carbon isotopes of the same teeth. This external forcing of trace element composition in mammal tooth enamel implies that trace element ratios may be used as proxies for seasonal changes in paleo-environment and paleo-diet.

  2. A triple axes multiple target holder assembly

    International Nuclear Information System (INIS)

    Tribedi, L.C.; Narvekar, S.D.; Pillay, R.G.; Tandon, P.N.

    1993-01-01

    We have designed and fabricated a rotatable target holder assembly capable of accommodating 27 targets. The target foils are mounted along two concentric circles on a ss wheel. On the outer circle 18 targets can be mounted each 20deg apart, and on the inner circle the remaining targets are positioned each 40deg apart. The self supporting or carbon backed targets are mounted on thin frames and are placed concentrically at the targets are mounted on thin frames and are placed concentrically at the target position on the wheel. Three degrees of freedom are provided to the target holder assembly. (author). 1 fig

  3. Analysis of phage Mu DNA transposition by whole-genome Escherichia coli tiling arrays reveals a complex relationship to distribution of target selection protein B, transcription and chromosome architectural elements.

    Science.gov (United States)

    Ge, Jun; Lou, Zheng; Cui, Hong; Shang, Lei; Harshey, Rasika M

    2011-09-01

    Of all known transposable elements, phage Mu exhibits the highest transposition efficiency and the lowest target specificity. In vitro, MuB protein is responsible for target choice. In this work, we provide a comprehensive assessment of the genome-wide distribution of MuB and its relationship to Mu target selection using high-resolution Escherichia coli tiling DNA arrays. We have also assessed how MuB binding and Mu transposition are influenced by chromosome-organizing elements such as AT-rich DNA signatures, or the binding of the nucleoid-associated protein Fis, or processes such as transcription. The results confirm and extend previous biochemical and lower resolution in vivo data. Despite the generally random nature of Mu transposition and MuB binding, there were hot and cold insertion sites and MuB binding sites in the genome, and differences between the hottest and coldest sites were large. The new data also suggest that MuB distribution and subsequent Mu integration is responsive to DNA sequences that contribute to the structural organization of the chromosome.

  4. Synthesis of superheavy elements by cold fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S [Gesellschaft fuer Schwerionenforschung (GSI), Helmholtzzentrum fuer Schwerionenforschung Gmbh (Germany)

    2009-12-31

    The nuclear shell model predicts that the next doubly magic shell-closure beyond {sup 208}Pb is at the proton number Z=114, 120, or 126 and at the neutron number N=172 or 184. The outstanding aim of experimental investigations is the exploration of this region of spherical 'Super Heavy Elements' (SHEs). Using cold fusion reactions which are based on lead and bismuth targets, the new elements from 107 to 112 were synthesized at GSI in Darmstadt, Germany. Some of these results were confirmed at RIKEN in Wako, Japan, where also a relatively neutron-deficient isotope of element 113 was synthesized. In hot fusion reactions of {sup 48}Ca projectiles with actinide targets, a more neutron-rich isotope of element 112 and the new elements from 113 to 116 and even 118 were produced at FLNR in Dubna, Russia. Recently, part of these hot fusion data, which represent the first identification of nuclei located on the predicted island of SHEs, were confirmed in two independent experiments. The decay data reveal that for the heaviest elements, the dominant decay mode is alpha emission rather than fission. The decay properties as well as reaction cross-sections are compared with results of theoretical studies.

  5. THE FIRST FLUORINE ABUNDANCE DETERMINATIONS IN EXTRAGALACTIC ASYMPTOTIC GIANT BRANCH CARBON STARS

    International Nuclear Information System (INIS)

    Abia, C.; Cristallo, S.; Dominguez, I.; Cunha, K.; Smith, V. V.; De Laverny, P.; Recio-Blanco, A.; Straniero, O.

    2011-01-01

    Fluorine ( 19 F) abundances (or upper limits) are derived in six extragalactic asymptotic giant branch (AGB) carbon stars from the HF(1-0) R9 line at 2.3358 μm in high-resolution spectra. The stars belong to the Local Group galaxies, Large Magellanic Cloud, Small Magellanic Cloud, and Carina dwarf spheroidal, spanning more than a factor of 50 in metallicity. This is the first study to probe the behavior of F with metallicity in intrinsic extragalactic C-rich AGB stars. Fluorine could be measured only in four of the target stars, showing a wide range in F enhancements. Our F abundance measurements together with those recently derived in Galactic AGB carbon stars show a correlation with the observed carbon and s-element enhancements. The observed correlations, however, display a different dependence on the stellar metallicity with respect to theoretical predictions in low-mass, low-metallicity AGB models. We briefly discuss the possible reasons for this discrepancy. If our findings are confirmed in a larger number of metal-poor AGBs, the issue of F production in AGB stars will need to be revisited.

  6. Investigating Rare Earth Element Systematics in the Marcellus Shale

    Science.gov (United States)

    Yang, J.; Torres, M. E.; Kim, J. H.; Verba, C.

    2014-12-01

    The lanthanide series of elements (the 14 rare earth elements, REEs) have similar chemical properties and respond to different chemical and physical processes in the natural environment by developing unique patterns in their concentration distribution when normalized to an average shale REE content. The interpretation of the REE content in a gas-bearing black shale deposited in a marine environment must therefore take into account the paleoredox conditions of deposition as well as any diagenetic remobilization and authigenic mineral formation. We analyzed 15 samples from a core of the Marcellus Shale (Whipkey ST1, Greene Co., PA) for REEs, TOC, gas-producing potential, trace metal content, and carbon isotopes of organic matter in order to determine the REE systematics of a black shale currently undergoing shale gas development. We also conducted a series of sequential leaching experiments targeting the phosphatic fractions in order to evaluate the dominant host phase of REEs in a black shale. Knowledge of the REE system in the Marcellus black shale will allow us to evaluate potential REE release and behavior during hydraulic fracturing operations. Total REE content of the Whipkey ST1 core ranged from 65-185 μg/g and we observed three distinct REE shale-normalized patterns: middle-REE enrichment (MREE/MREE* ~2) with heavy-REE enrichment (HREE/LREE ~1.8-2), flat patterns, and a linear enrichment towards the heavy-REE (HREE/LREE ~1.5-2.5). The MREE enrichment occurred in the high carbonate samples of the Stafford Member overlying the Marcellus Formation. The HREE enrichment occurred in the Union Springs Member of the Marcellus Formation, corresponding to a high TOC peak (TOC ~4.6-6.2 wt%) and moderate carbonate levels (CaCO3 ~4-53 wt%). Results from the sequential leaching experiments suggest that the dominant host of the REEs is the organic fraction of the black shale and that the detrital and authigenic fractions have characteristic MREE enrichments. We present our

  7. Effect of Carbon Concentration on the Sputtering of Carbon-Rich SiC Bombarded by Helium Ions

    Directory of Open Access Journals (Sweden)

    Xinghao Liang

    2018-02-01

    Full Text Available Silicon carbide (SiC is considered as an important material for nuclear engineering due to its excellent properties. Changing the carbon content in SiC can regulate and control its elastic and thermodynamic properties, but a simulation study of the effect of carbon content on the sputtering (caused by the helium ions of SiC is still lacking. In this work, we used the Monte-Carlo and molecular dynamics simulation methods to study the effects of carbon concentration, incidence energy, incident angle, and target temperature on the sputtering yield of SiC. The results show that the incident ions’ energy and angle have a significant effect on sputtering yield of SiC when the carbon concentration in SiC is around 62 at %, while the target temperature has a little effect on the sputtering yield of SiC. Our work might provide theoretical support for the experimental research and engineering application of carbon fiber-reinforced SiC that be used as the plasma-facing material in tokamak fusion reactors.

  8. Effects of industrial by-product amendments on As, Cd and Tl retention/release in an element-spiked acidic soil

    International Nuclear Information System (INIS)

    Aguilar-Carrillo, Javier; Barrios, Laura; Garrido, Fernando; Garcia-Gonzalez, Maria Teresa

    2007-01-01

    To asses the efficiency of two by-products (phosphogypsum (PG) and sugar foam (SF), rich in gypsum and calcium carbonate, respectively) in the immobilization of three toxic elements (As, Cd and Tl) in an acidic soil, batch-scale sorption and desorption experiments were conducted after 18 months of in situ amendment application. The Langmuir isotherms applied for sorption studies showed that the estimated maximum sorption capacity of the elements was highest in the SF-treated samples. The amount of element retained and the percentage of extraction after TCLP tests indicated that those samples amended with sugar foam (SF and PG + SF) had the potential to immobilize As, Cd and Tl in an acidic soil with low sorptive capacity. In addition to sorption and desorption experiments, scanning electron microscopy in back-scattered electron mode (SEM-BSE) showed the formation of Al-hydroxy polymers which provides the soil with additional sorption capacity. The three target elements were associated with the Al-hydroxy polymers, probably through direct coordination or the formation of ternary complexes. By means of statistical analysis it has been found that sorption processes of As, Cd and Tl in this soil mainly depend on the treatment, whereas desorption is an element-dependent process

  9. Radiation damage in carbon-carbon composites: Structure and property effects

    International Nuclear Information System (INIS)

    Burchell, T.D.

    1995-01-01

    Carbon-carbon composites are an attractive choice for fusion reactor plasma facing components because of their low atomic number, superior thermal shock resistance, and low neutron activation. Next generation tokamak reactors such as the International Thermonuclear Experimental Reactor (ITER), will require high thermal conductivity carbon-carbon composites and other materials, such as beryllium, to protect their plasma facing components from the anticipated high heat fluxes. Moreover, ignition machines such as ITER will produce a large neutron flux. Consequently, the influence of neutron damage on the structure and properties of carbon-carbon composite materials must be evaluated. Data from two irradiation experiments are reported and discussed here. Carbon-carbon composite materials were irradiated in target capsules in the High Flux Isotope Reactor (HAIR) at Oak Ridge National Laboratory (ORAL). A peak damage dose of 4.7 displacements per atom (da) at an irradiation temperature of ∼600 degrees C was attained. The carbon materials irradiated here included unidirectional, two- directional, and three-directional carbon-carbon composites. Irradiation induced dimensional changes are reported for the materials and related to single crystal dimensional changes through fiber and composite structural models. Moreover, carbon-carbon composite material dimensional changes are discussed in terms of their architecture, fiber type, and graphitization temperature. Neutron irradiation induced reductions in the thermal conductivity of two, three-directional carbon-carbon composites are reported, and the recovery of thermal conductivity due to thermal annealing is demonstrated. Irradiation induced strength changes are reported for several carbon-carbon composite materials and are explained in terms of in-crystal and composite structural effects

  10. Natural fracking and the genesis of five-element veins

    Science.gov (United States)

    Markl, Gregor; Burisch, Mathias; Neumann, Udo

    2016-08-01

    Hydrothermal Ag-Co-Ni-Bi-As (five-element vein type) ore deposits show very conspicuous textures of the native elements silver, bismuth, and arsenic indicating formation from a rapid, far-from-equilibrium process. Such textures include up to dm-large tree- and wire-like aggregates overgrown by Co-Ni-Fe arsenides and mostly carbonates. Despite the historical and contemporary importance of five-element vein type deposits as sources of silver, bismuth, and cobalt, and despite of spectacular museum specimens, their process of formation is not yet understood and has been a matter of debate since centuries. We propose, based on observations from a number of classical European five-element vein deposits and carbon isotope analyses, that "natural fracking," i.e., liberation of hydrocarbons or hydrocarbon-bearing fluids during break up of rocks in the vicinity of an active hydrothermal system and mixing between these hydrocarbons (e.g., methane and/or methane-bearing fluids) and a metal-rich hydrothermal fluid is responsible for ore precipitation and the formation of the unusual ore textures and assemblages. Thermodynamic and isotope mixing calculations show that the textural, chemical, and isotopic features of the investigated deposits can entirely be explained by this mechanism.

  11. Preparation of isotopically enriched mercury sulphide targets

    Energy Technology Data Exchange (ETDEWEB)

    Szerypo, J.; Friebel, H.U.; Frischke, D.; Grossman, R.; Maier, H.J. [Dept. fuer Physik, Univ. Muenchen (LMU) (Germany); Maier-Leibnitz-Lab. (MLL), Garching (Germany)

    2007-07-01

    The primary difficulty in performing nuclear reactions on mercury is to obtain a suitable target. The primary difficulty in performing nuclear reactions on mercury is to obtain a suitable target. The utilization of amalgam targets has been reported in early publications. These targets, however, were lacking homogeneity and in-beam stability. A thorough investigation of literature shows, that HgS, because of its comparatively high chemical and mechanical stability, is one of the more adequate Hg compounds for accelerator target applications. In this presentation we describe the production of HgS targets consisting of an enriched Hg isotope and S of natural isotopic abundance, starting up from HgO. Following the outline given in [3], in this special case HgS can be prepared by dissolving HgO in diluted HNO{sub 3} and subsequent precipitation of the black HgS modification with gaseous H{sub 2}S. Last step of the target production procedure is evaporation-condensation of HgS in vacuum. In the present case, HgS layers of 500 {mu}g/cm{sup 2} on a backing carbon foil of 26 {mu}g/cm{sup 2} with a protective carbon layer of about 20 {mu}g/cm{sup 2} thickness on top of the HgS layer were produced. (orig.)

  12. Study of errors of calculation of elements of target functions of a model of future development and disposition of coal mining for coking

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, M I

    1979-01-01

    The boundaries of the coefficients of increase of volume of capital investments for a production construction (K) and net cost (C) of mining of commercial coal for the principal coal basins and the most probable values of errors of these quantities as a whole for the sample examined are obtained. Dependency of the increase of the elements of the target function of the model on increase of K and C is plotted.

  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. Conducting carbonized polyaniline nanotubes

    International Nuclear Information System (INIS)

    Mentus, Slavko; Ciric-Marjanovic, Gordana; Trchova, Miroslava; Stejskal, Jaroslav

    2009-01-01

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 deg. C min -1 up to a maximum temperature of 800 deg. C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 μm, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 μm, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm -1 , increased to 0.7 S cm -1 upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  15. Conducting carbonized polyaniline nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mentus, Slavko; Ciric-Marjanovic, Gordana [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade (Serbia); Trchova, Miroslava; Stejskal, Jaroslav [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Square 2, 162 06 Prague 6 (Czech Republic)], E-mail: gordana@ffh.bg.ac.rs

    2009-06-17

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 deg. C min{sup -1} up to a maximum temperature of 800 deg. C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 {mu}m, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 {mu}m, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm{sup -1}, increased to 0.7 S cm{sup -1} upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  16. Amplification of biological targets via on-chip culture for biosensing

    Science.gov (United States)

    Harper, Jason C.; Edwards, Thayne L.; Carson, Bryan; Finley, Melissa; Arndt, William

    2018-01-02

    The present invention, in part, relates to methods and apparatuses for on-chip amplification and/or detection of various targets, including biological targets and any amplifiable targets. In some examples, the microculture apparatus includes a single-use, normally-closed fluidic valve that is initially maintained in the closed position by a valve element bonded to an adhesive coating. The valve is opened using a magnetic force. The valve element includes a magnetic material or metal. Such apparatuses and methods are useful for in-field or real-time detection of targets, especially in limited resource settings.

  17. Characterization and Comparison of Aluminum, Silicon, and Carbon Laser Ablation Plumes

    Science.gov (United States)

    Iratcabal, Jeremy; Swanson, Kyle; Covington, Aaron

    2017-10-01

    Laser ablation of solid targets produces plasma plumes with rapidly evolving temperature and density gradients. These gradients can be measured using laser interferometric techniques that allow for the study of the plasma as the plume expands from the target surface and the temperature and density decrease. A systematic study of the temperature and density of aluminum, silicon, and carbon plasma plumes produced with a 2 TW/cm2 laser using spectroscopic, interferometric, fast imaging, and charge diagnostics will be presented. Carbon, aluminum, and silicon plumes are of interest because they are closely grouped on the periodic table but have very different material characteristics. Temporally and spatially resolved data was collected to characterize the evolution of the plasma in the plume. To probe the plasmas produced from these materials, optical spectroscopy was employed to identify and measure the temperature of the coexisting neutral and ionized atomic and molecular species. A Mach-Zehnder interferometer was employed to measure electron density. ICCD imaging and shadowgraphy were used to image the plume dynamics. A comparison of plasma evolution for each element will also be presented and will provide data to benchmark plasma codes. This work was supported by the University of Nevada, Reno, the U.S. DOE /NNSA Cooperative Agreement No. DE-NA0002075, and National Securities Technologies, LLC under Contract No. DE-AC52-06NA25946/Subcontract No. 165819.

  18. Decrease of concentration and colloidal fraction of organic carbon and trace elements in response to the anomalously hot summer 2010 in a humic boreal lake.

    Science.gov (United States)

    Shirokova, L S; Pokrovsky, O S; Moreva, O Yu; Chupakov, A V; Zabelina, S A; Klimov, S I; Shorina, N V; Vorobieva, T Ya

    2013-10-01

    The colloidal distribution and size fractionation of organic carbon (OC), major elements and trace elements (TE) were studied in a seasonally stratified, organic-rich boreal lake, Lake Svyatoe, located in the European subarctic zone (NW Russia, Arkhangelsk region). This study took place over the course of 4 years in both winter and summer periods using an in situ dialysis technique (1 kDa, 10 kDa and 50 kDa) and traditional frontal filtration and ultrafiltration (5, 0.22 and 0.025 μm). We observed a systematic difference in dissolved elements and colloidal fractions between summer and winter periods with the highest proportion of organic and organo-ferric colloids (1 kDa-0.22 μm) observed during winter periods. The anomalously hot summer of 2010 in European Russia produced surface water temperatures of approximately 30°C, which were 10° above the usual summer temperatures and brought about crucial changes in element speciation and size fractionation. In August 2010, the concentration of dissolved organic carbon (DOC) decreased by more than 30% compared to normal period, while the relative proportion of organic colloids decreased from 70-80% to only 20-30% over the full depth of the water column. Similarly, the proportion of colloidal Fe decreased from 90-98% in most summers and winters to approximately 60-70% in August 2010. During this hot summer, measurable and significant (>30% compared to other periods) decreases in the colloidal fractions of Ca, Mg, Sr, Ba, Al, Ti, Ni, As, V, Co, Y, all rare earth elements (REEs), Zr, Hf, Th and U were also observed. In addition, dissolved (organic matter by heterotrophic aerobic bacterioplankton and 3) photo-degradation of DOM and photo-chemical liberation of organic-bound TE. While the first process may have caused significant decreases in the total dissolved concentration of micronutrients (a factor of 2 to 5 for Cr, Mn, Fe, Ni, Cu, Zn and Cd and a factor of >100 for Co), the second and third factors could have brought

  19. Superheavy elements in D I Mendeleev's Periodic Table

    Energy Technology Data Exchange (ETDEWEB)

    Oganessian, Yury Ts; Dmitriev, Sergey N [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Moscow Region (Russian Federation)

    2009-12-31

    The results on the synthesis of new superheavy elements, synthesized in complete fusion reactions of {sup 48}Ca ions with actinide targets, are summarized and analyzed. The perspectives for the synthesis of element 117, as well as of elements with Z>=118 are also considered.

  20. 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).

  1. Interface Analyses Between a Case-Hardened Ingot Casting Steel and Carbon-Containing and Carbon-Free Refractories

    Science.gov (United States)

    Fruhstorfer, Jens; Dudczig, Steffen; Rudolph, Martin; Schmidt, Gert; Brachhold, Nora; Schöttler, Leandro; Rafaja, David; Aneziris, Christos G.

    2018-06-01

    Corrosion tests of carbon-free and carbon-containing refractories were performed. The carbon-free crucibles corroded, whereas the carbon-containing crucibles were negligibly attacked. On them, inclusions were attached. This study investigates melt oxygen contents, interface properties, and steel compositions with their non-metallic inclusions in order to explore the inclusion formation and deposition mechanisms. The carbon-free crucibles were based on alumina, mullite, and zirconia- and titania-doped alumina (AZT). The carbon-containing (-C) ones were alumina-C and AZT-C. Furthermore, nanoscaled carbon and alumina additives (-n) were applied in an AZT-C-n material. In the crucibles, the case-hardened steel 17CrNiMo7-6 was remelted at 1580 °C. It was observed that the melt and steel oxygen contents were higher for the tests in the carbon-free crucibles. Into these crucibles, the deoxidizing alloying elements Mn and Si diffused. Reducing contents of deoxidizing elements resulted in higher steel oxygen levels and less inclusions, mainly of the inclusion group SiO2-core-MnS-shell (2.5 to 8 μ m). These developed from smaller SiO2 nuclei. The inclusion amount in the steel was highest after remelting in AZT-C-n for 30 minutes but decreased strongly with increasing remelting time (60 minutes) due to inclusions' deposition on the refractory surface. The Ti from the AZT and the nanoadditives supported inclusion growth and deposition. Other inclusion groups were alumina and calcium aluminate inclusions. Their contents were high after remelting in carbon- or AZT-containing crucibles but generally decreased during remelting. On the AZT-C-n crucible, a dense layer formed from vitreous compositions including Al, Ca, Mg, Si, and Ti. To summarize, for reducing forming inclusion amounts, mullite is recommended as refractory material. For capturing formed inclusions, AZT-C-n showed a high potential.

  2. SU-E-T-244: Designing Low-Z Targets To Enhance Surface Dose: A Monte Carlo Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, R [Nova Scotia Cancer Centre, Halifax, NS (Canada); Robar, J [Capital District Health Authority, Halifax, NS (Canada); Parsons, D [Dalhousie University, Halifax, Nova Scotia (Canada)

    2015-06-15

    Purpose: Recent developments in The Varian Truebeam linac platform allows for the introduction of low-Z targets into the beam line for the imaging purposes. We have proposed using a low-Z target for radiation therapy purposes to enhance the surface dose during radiation treatment. The target arm of the Varian Truebeam accelerator consists of multiple targets with are linearly translated into the beam line. We have designed two Low-Z targets made of carbon: 1) a step target consisting of three steps of 15%, 30% and 60% CSDA range for 2.5 MeV electrons Figure 1a; 2) and a ramp target, an incline plane 2cm long with thicknesses ranging from 0% to 60% CSDA range, Figure 1b. The purpose of this work will determine the spectral characteristics of these target designs and determine if they have practical clinical applications for enhancing surface dose. Methods: To calculate the spectral characteristics of these targets, a standard Monte Carlo model of a Varian Clinac accelerator was used. Simulations were performed with a carbon step target, and a carbon ramp target, located at the same position as the electron foil in the rotating carousel. Simulations were carried out using a 2.5 MeV electron beam. Results: The step target design produced spectral characteristics which were similar to spectral model using a single disk target of the same thickness. The ramp target provides a means to have positional variation of the spectral components of the beam, however, the electron component as 60% CSDA us much broader than the step target. Conclusion: The carbon step-target provides a spectral distribution which is similar to a carbon disk of comparable thickness. The spectral distribution from the ramp-target can be modified as a function of position to provide a wide range of low energy electrons for surface dose enhancement.

  3. Quality of poultry litter-derived granular activated carbon.

    Science.gov (United States)

    Qiu, Guannan; Guo, Mingxin

    2010-01-01

    Utilization of poultry litter as a source material for generating activated carbon is a value-added and environmentally beneficial approach to recycling organic waste. In this study, the overall quality of poultry litter-derived granular activated carbon was systematically evaluated based on its various physical and chemical properties. Granular activated carbon generated from pelletized poultry litter following a typical steam-activation procedure possessed numerous micropores in the matrix. The product exhibited a mean particle diameter of 2.59 mm, an apparent density of 0.45 g cm(-3), a ball-pan hardness of 91.0, an iodine number of 454 mg g(-1), and a BET surface area of 403 m(2) g(-1). It contained high ash, nitrogen, phosphorus contents and the trace elements Cu, Zn, and As. Most of the nutrients and toxic elements were solidified and solution-unextractable. In general, poultry litter-based activated carbon demonstrated overall quality comparable to that of low-grade commercial activated carbon derived from coconut shell and bituminous coal. It is promising to use poultry litter as a feedstock to manufacture activated carbon for wastewater treatment.

  4. Bainite formation kinetics in high carbon alloyed steel

    International Nuclear Information System (INIS)

    Luzginova, N.V.; Zhao, L.; Sietsma, J.

    2008-01-01

    In recent years, many investigations have been carried out on the modeling of the bainite formation. In the present work, a physical approach proposed in the literature is implemented to model the formation of lower bainite in high carbon steels (1 wt.% C). In this model, the carbon diffusion is assumed to control the kinetics of the bainite formation. Both the nucleation and the growth rates are considered in an Avrami type analysis. The effect of alloying elements is taken into account considering only the thermodynamics of the system. The results and the physical meaning of the model parameters are discussed. It is shown that the diffusional approach gives a reasonable description of bainite formation kinetics in high carbon steel. Only two fitting parameters are used: the first accounts for carbon grain-boundary diffusion and the second is the initial nucleation-site density. The model satisfactorily accounts for the effect of transformation temperature, but does not take into account the carbide precipitation during bainite formation and the effect of alloying elements on the diffusion coefficient of carbon

  5. 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.

  6. Recent searches for superheavy elements in deep-inelastic reactions

    International Nuclear Information System (INIS)

    Hulet, E.K.; Lougheed, R.W.; Nitschke, J.M.

    1980-10-01

    New attempts have been made to synthesize superheavy elements (SHE) by nuclear reactions that may possibly form the products at low excitation energies. Survival of the superheavy elements would then be enhanced because of reduced losses from prompt fission. Classical and diffusion-model calculations of deep-inelastic reactions indicate there should be detectable yields of SHE formed with less than 30 MeV of excitation energy. Accordingly, superheavy elements have been sought in such reactions where targets of 248 Cm and 238 U have been irradiated with 136 Xe and 238 U ions. In the most recent experiments, targets of 248 Cm metal (3.5 to 7 mg-cm -2 ) were bombarded with 1.8-GeV 238 U ions from the UNILAC accelerator. The longer-lived SHE and actinides near the target Z were chemically separated, and the yields of a number of isotopes of Bk, Cf, Es, and Fm were measured. An upper limit of 30 nb was obtained for the formation of 1-h 259 No. In addition to the off-line chemical recovery and search for SHE, an on-line experiment was performed to detect volatile SHE with half-lives of a minute or more. All experiments to produce and detect superheavy elements were much less than optimum because of premature failures in the Cm-metal targets. The outcome and status of these experiments and the implications of the actinide yields in estimating the chances for forming superheavy elements in the 248 Cm + 238 U reactions are discussed. 5 figures, 1 table

  7. Mesh-morphing algorithms for specimen-specific finite element modeling.

    Science.gov (United States)

    Sigal, Ian A; Hardisty, Michael R; Whyne, Cari M

    2008-01-01

    Despite recent advances in software for meshing specimen-specific geometries, considerable effort is still often required to produce and analyze specimen-specific models suitable for biomechanical analysis through finite element modeling. We hypothesize that it is possible to obtain accurate models by adapting a pre-existing geometry to represent a target specimen using morphing techniques. Here we present two algorithms for morphing, automated wrapping (AW) and manual landmarks (ML), and demonstrate their use to prepare specimen-specific models of caudal rat vertebrae. We evaluate the algorithms by measuring the distance between target and morphed geometries and by comparing response to axial loading simulated with finite element (FE) methods. First a traditional reconstruction process based on microCT was used to obtain two natural specimen-specific FE models. Next, the two morphing algorithms were used to compute mappings from the surface of one model, the source, to the other, the target, and to use this mapping to morph the source mesh to produce a target mesh. The microCT images were then used to assign element-specific material properties. In AW the mappings were obtained by wrapping the source and target surfaces with an auxiliary triangulated surface. In ML, landmarks were manually placed on corresponding locations on the surfaces of both source and target. Both morphing algorithms were successful in reproducing the shape of the target vertebra with a median distance between natural and morphed models of 18.8 and 32.2 microm, respectively, for AW and ML. Whereas AW-morphing produced a surface more closely resembling that of the target, ML guaranteed correspondence of the landmark locations between source and target. Morphing preserved the quality of the mesh producing models suitable for FE simulation. Moreover, there were only minor differences between natural and morphed models in predictions of deformation, strain and stress. We therefore conclude that

  8. 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

  9. 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

  10. Radiochemical aspects of liquid mercury spallation targets

    CERN Document Server

    Neuhausen, Joerg; Eichler, Bernd; Eller, Martin; Horn, Susanne; Schumann, Dorothea; Stora, Thierry

    2012-01-01

    Liquid metal spallation targets using mercury as target material are used in state-of-the-art high power pulsed neutron sources that have been constructed in the USA and Japan within the last decade. Similar target concepts were also proposed for next generation ISOL, beta-beam and neutrino facilities. A large amount of radioactivity will be induced in the liquid metal during operation caused by the interaction of the target material with the intense proton beam. This radioactivity - carried by a wide range of radioisotopes of all the elements of the periodic table from hydrogen up to thallium - must be considered for the assessment of safe operation and maintenance procedures as well as for a final disposal of the used target material and components. This report presents an overview on chemical investigations performed in our laboratory that deal with the behavior of radionuclides in proton irradiated mercury samples. The solubility of elements in mercury was calculated using thermodynamical data obtained by...

  11. International Nuclear Target Development Society workshop 1983: proceedings

    International Nuclear Information System (INIS)

    Thomas, G.

    1983-01-01

    Separate abstracts were prepared for 11 of the 19 papers presented. Eight papers were previously included in the data base. Discussion group session papers on carbon stripper foils, problems in producing heavy-ion targets, and problems in producing general type targets are included

  12. Eikonal phase shift analyses of carbon-carbon scattering

    International Nuclear Information System (INIS)

    Townsend, L.W.; Bidasaria, H.B.; Wilson, J.W.

    1983-01-01

    A high-energy double-folding optical potential approximation to the exact nucleus-nucleus multiple-scattering series is used to determine eikonal phase shifts for carbon-carbon scattering at 204.2, 242.7, and 288.6 MeV. The double-folding potentials are obtained by folding the energy-dependent free nucleon-nucleon interaction with densities for the projectile and target obtained by unfolding the finite nucleon charge density from harmonic-well carbon charge distributions. The charge parameters for the latter are taken from the results of electron scattering experiments. Predictions for total, reaction, and elastic differential cross sections, using standard partial wave analysis for the scattering of identical particles, are made and compared with recent experimental results. Excellent agreement is obtained although there are no arbitrarily adjusted parameters in the theory

  13. The effects of oxides of carbon and nitrogen emissions on the isotope and element abundances in foliage of C3 plants

    International Nuclear Information System (INIS)

    Sucgang, Raymond; Pabroa, Preciosa Corazon; Petrache, Cristina; Bulanhagui, Jaika Faye; Legaspi, Charmaine; Niegas, Elaine; Enerva, Lorna; Luces, Arnicole

    2014-01-01

    The carbon and nitrogen stable isotope abundance of C3 plants mango (Magnifera indica L), molave (Vitex parviflora Juss), talisay (Terminalia catappa L.) leaves harvested from sites with ambient air conditions and sites receiving air pollution contributions from coal-fired power plants were determined and compared. Isotope Ratio Mass Spectroscopy, IRMS was used to determine 13 C and 15 N in the samples. The elemental composition of the samples was determined using Inductively Coupled Plasma-Atomic Emission Spectrometry, ICP-AES. The 13 C of the leaves grown in ambient air were found to fall within the range of -25.0 to -22.0 per mill and a close agreement with the literature values for the natural abundance of 13 C in C3 plants (-27.0 to -21.0 per mill). The 13 C abundance of plants obtained from sites polluted by coal-fired plants were sporadic from -35 to 24.0 per mille. The 15 N abundance in leaves grown under ambient air condition (-1.0 to 2.0 per mille) were way below the 15 N abundance of plants from coal-fired plant-polluted regions (16.0 to 17.5 per mille). Elemental exposition indicated no differences in element concentrations in leaves from ambient and polluted sites. Differences exist in the Ca, Mg, K ratios across species and are affected by seasonal variation. (author)

  14. A literature review of actinide-carbonate mineral interactions

    International Nuclear Information System (INIS)

    Stout, D.L.

    1993-10-01

    Chemical retardation of actinides in groundwater systems is a potentially important mechanism for assessing the performance of the Waste Isolation Pilot Plant (WIPP), a facility intended to demonstrate safe disposal of transuranic waste. Rigorous estimation of chemical retardation during transport through the Culebra Dolomite, a water-bearing unit overlying the WIPP, requires a mechanistic understanding of chemical reactions between dissolved elements and mineral surfaces. This report represents a first step toward this goal by examining the literature for pertinent experimental studies of actinide-carbonate interactions. A summary of existing models is given, along with the types of experiments on which these models are based. Articles pertaining to research into actinide interactions with carbonate minerals are summarized. Select articles involving trace element-carbonate mineral interactions are also reviewed and may serve as templates for future research. A bibliography of related articles is included. Americium(III), and its nonradioactive analog neodymium(III), partition strongly from aqueous solutions into carbonate minerals. Recent thermodynamic, kinetic, and surface studies show that Nd is preferentially removed from solution, forming a Nd-Ca carbonate solid solution. Neptunium(V) is rapidly removed from solution by carbonates. Plutonium incorporation into carbonates is complicated by multiple oxidation states. Little research has been done on the radium(H) and thorium(IV) carbonate systems. Removal of uranyl ion from solution by calcite is limited to monolayer surface coverage

  15. Target validation for FCV technology development in Japan from energy competition point of view

    International Nuclear Information System (INIS)

    ENDO Eiichi

    2006-01-01

    The objective of this work is to validate the technical targets in the governmental hydrogen energy road-map of Japan by analyzing market penetration of fuel cell vehicle(FCV)s and effects of fuel price and carbon tax on it from technology competition point of view. In this analysis, an energy system model of Japan based on MARKAL is used. The results of the analysis show that hydrogen FCVs could not have cost-competitiveness until 2030 without carbon tax, including the governmental actual plan of carbon tax. However, as the carbon tax rate increases, instead of conventional vehicles including gasoline hybrid electric vehicle, hydrogen FCVs penetrate to the market earlier and more. By assuming higher fuel price and severer carbon tax rate, market share of hydrogen FCVs approaches to the governmental goal. This suggests that cheaper vehicle cost and/or hydrogen price than those targeted in the road-map is required. At the same time, achievement of the technical targets in the road-map also allows to attain the market penetration target of hydrogen FCVs in some possible conditions. (authors)

  16. Electrocatalytic process for carbon dioxide conversion

    Science.gov (United States)

    Masel, Richard I.; Salehi-Khojin, Amin; Kutz, Robert

    2017-11-14

    An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and a Helper Polymer in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said carbon dioxide reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. The reaction products comprise at least one of CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, (COO.sup.-).sub.2, and CF.sub.3COOH.

  17. Multiply charged ions of the oxygen - produced at interaction of laser radiation with two-element solids

    International Nuclear Information System (INIS)

    Bedilov, M.R.; Bedilov, R.M.; Kamalova, J.O.; Davletov, I.Yu.; Matnazarov, A.R.

    2007-01-01

    Full text: The interest to study of the oxygen multiply charged ions spectra produced at interaction laser radiation with one and two-element solids, is associate with possibility of creating laser and inertial thermonuclear syntheses, effective sources of multiply charged ions and nuclei atoms elements, plasma lasers, lasers on multiply charged transition, design of radiation-resistant materials and others. The present time many works is devoted to multiply charged ions, obtained from one element targets. Experimental results of study charge and energy spectra multiply charged ions of the oxygen, formed at interaction laser radiation with one and two-element solids are given in this work. Our experiments, we used installation, which is described in [1]. Neodymium laser had following parameters: wavelength 1.06 μm; intensity q = (0.1 h 1000) GW/sm 2 ; angle of incidence = 180. Were study one element Al, and two-element Al 2 O 3 , Y 2 O 3 targets by a diameter of 10 mm and thickness of 3 mm. Analysis obtained charge and energy spectra of multiply charged ions one (Al) and two-element (Al 2 O 3 , Y 2 O 3 ) targets depending on intensity of laser radiation and targets components reveal the following: - maximal charge number one element target (Al) at q 500 GW/sm 2 is equal Z max = 6 and all peaks corresponding to charge numbers Z = 1 - 6 well resolved, but two-element targets (Al 2 O 3 ) Z max ions Al decrease before 3. Also it is necessary to note that, Z max ions of the oxygen depend on target components. In case Al 2 O 3 and Y 2 O 3 maximal charge number of oxygen ions are equal Z max = 6 and 3, accordingly; - obtained charge and energy spectra of oxygen ions being included in two-element targets, are indicative of that, general regularities of the change Z max , E max and structures charge and energy spectra depending on q laser are saved. However they hang by target components; - common features and some differences of energy spectra multiply charged oxygen ions

  18. An Experiment on the Carbonization of Fuel Compact Matrix Graphite for HTGR

    International Nuclear Information System (INIS)

    Lee, Young Woo; Kim, Joo Hyoung; Cho, Moon Sung

    2012-01-01

    The fuel element for HTGR is manufactured by mixing coated fuel particles with matrix graphite powder and forming into either pebble type or cylindrical type compacts depending on their use in different HTGR cores. The coated fuel particle, the so-called TRISO particle, consists of 500-μm spherical UO 2 particles coated with the low density buffer Pyrolytic Carbon (PyC) layer, the inner and outer high density PyC layer and SiC layer sandwiched between the two inner and outer PyC layers. The coated TRISO particles are mixed with a properly prepared matrix graphite powder, pressed into a spherical shape or a cylindrical compact, and finally heat-treated at about 1800 .deg. C. These fuel elements can have different sizes and forms of compact. The basic steps for manufacturing a fuel element include preparation of graphite matrix powder, over coating the fuel particles, mixing the fuel particles with a matrix powder, carbonizing green compact, and the final high-temperature heat treatment of the carbonized fuel compact. The carbonization is a process step where the binder that is incorporated during the matrix graphite powder preparation step is evaporated and the residue of the binder is carbonized during the heat treatment at about 1073 K, In order to develop a fuel compact fabrication technology, and for fuel matrix graphite to meet the required material properties, it is of extreme importance to investigate the relationship among the process parameters of the matrix graphite powder preparation, fabrication parameters of fuel element green compact and the carbonization condition, which has a strong influence on further steps and the material properties of fuel element. In this work, the carbonization behavior of green compact samples prepared from the matrix graphite powder mixtures with different binder materials was investigated in order to elucidate the behavior of binders during the carbonization heat treatment by analyzing the change in weight, density and its

  19. The foil equilibration method for carbon in sodium

    Energy Technology Data Exchange (ETDEWEB)

    Borgstedt, H; Frees, G; Peric, Z [Karlsruhe Nuclear Research Center, Institute of Materials and Solid State Research, Karlsruhe (Germany)

    1980-05-01

    Among the non-metallic impurities in sodium, carbon plays an important role since at high temperatures the structural materials exposed to sodium are subject to carburization and decarburization depending on the carbon activity of the sodium. Carburization of austenitic stainless steels leads to reduction in ductility and fatigue properties whereas decarburization results in a decrease in the high temperature creep strength. A knowledge of the carbon activities in sodium will help understanding of the carbon transfer phenomena in operating sodium systems of the fast reactors, and also carbon diffusion, microstructural stability and mechanical behaviour of materials under different service conditions. An understanding of the carbon behaviour in sodium becomes difficult in view of the complexities of the different species present as elemental carbon, carbide, acetylide, carbonate, and cyanide. Carbon estimation techniques for sodium presently in use are: chemical analytical methods, on-line carbon monitors, and oil equilibration method. Various chemical methods have been developed for the estimation of different species like acetylide, cyanide, carbonate, elemental carbon, and total carbon in sodium. All these methods are time consuming and subject to various errors. The on-line monitors developed for carbon in sodium are able to give continuous indication of carbon activities and have higher sensitivity than the chemical methods. A still more simple method for the determination of carbon activities is by the foil equilibration first published by Natesan et al. Because of its simplicity like the vanadium wire equilibration for oxygen it is being used widely for the estimation of carbon activities in sodium systems. Carbon concentrations in operating sodium systems estimated by this procedure by applying solubility relation to carbon activities have yielded very low values of carbon, lower than the sensitivity limits of the chemical estimation methods. Foil

  20. The foil equilibration method for carbon in sodium

    International Nuclear Information System (INIS)

    Borgstedt, H.; Frees, G.; Peric, Z.

    1980-01-01

    Among the non-metallic impurities in sodium, carbon plays an important role since at high temperatures the structural materials exposed to sodium are subject to carburization and decarburization depending on the carbon activity of the sodium. Carburization of austenitic stainless steels leads to reduction in ductility and fatigue properties whereas decarburization results in a decrease in the high temperature creep strength. A knowledge of the carbon activities in sodium will help understanding of the carbon transfer phenomena in operating sodium systems of the fast reactors, and also carbon diffusion, microstructural stability and mechanical behaviour of materials under different service conditions. An understanding of the carbon behaviour in sodium becomes difficult in view of the complexities of the different species present as elemental carbon, carbide, acetylide, carbonate, and cyanide. Carbon estimation techniques for sodium presently in use are: chemical analytical methods, on-line carbon monitors, and oil equilibration method. Various chemical methods have been developed for the estimation of different species like acetylide, cyanide, carbonate, elemental carbon, and total carbon in sodium. All these methods are time consuming and subject to various errors. The on-line monitors developed for carbon in sodium are able to give continuous indication of carbon activities and have higher sensitivity than the chemical methods. A still more simple method for the determination of carbon activities is by the foil equilibration first published by Natesan et al. Because of its simplicity like the vanadium wire equilibration for oxygen it is being used widely for the estimation of carbon activities in sodium systems. Carbon concentrations in operating sodium systems estimated by this procedure by applying solubility relation to carbon activities have yielded very low values of carbon, lower than the sensitivity limits of the chemical estimation methods. Foil

  1. Elemental ABAREX -- a user's manual

    International Nuclear Information System (INIS)

    Smith, A.B.

    1999-01-01

    ELEMENTAL ABAREX is an extended version of the spherical optical-statistical model code ABAREX, designed for the interpretation of neutron interactions with elemental targets consisting of up to ten isotopes. The contributions from each of the isotopes of the element are explicitly dealt with, and combined for comparison with the elemental observables. Calculations and statistical fitting of experimental data are considered. The code is written in FORTRAN-77 and arranged for use on the IBM-compatible personal computer (PC), but it should operate effectively on a number of other systems, particularly VAX/VMS and IBM work stations. Effort is taken to make the code user friendly. With this document a reasonably skilled individual should become fluent with the use of the code in a brief period of time

  2. On kinetics of carbothermal reduction of subgroup 2A elements of the Periodic chart

    International Nuclear Information System (INIS)

    Vodop'yanov, A.G.; AN SSSR, Sverdlovsk. Inst. Metallurgii)

    1984-01-01

    An attempt was made on the basis of a new version of Periodical system to clarify the general regularities of kinetics and transformation mechanism of metal oxides of 2nd A subgroup during their interaction with carbon (in furnaces at approximately 1700-2300 K). According to a new version of Periodic system Ca, Sr, Ba represent both type- and shell-analogs and Ra-shrink-analog of barium. Their full-valent cations in corresponding oxides possess similar structure corresponding to external electronic shells of inert gases with vacant α-shells. Be and Mg represent only type-analogs. Their full-valent cations in corresponding oxides possess ionic electronic structure corresponding to external S 2 - and S 2 p 6 -shells. It is shown that during interaction of solid oxides of 2nd A subgroup elements with carbon similarity of physicochemical properties of type-analog elements is manifested by the presence of common reduction mechanism - interaction proceeds through the gaseous phase with participation of CO as reducer, carbon regenerates CO and forms carbides of corresponding elements. The expected close similarity of properties for oxides of shell-analog elements s manifested additionally in the form of common dependence of change of rate constant of oxide transformation on the value of Gibbs free energy of reduction by carbon up to the vapor of correspondng metal

  3. The review of recent carbonate minerals processing technology

    Science.gov (United States)

    Solihin

    2018-02-01

    Carbonate is one of the groups of minerals that can be found in relatively large amount in the earth crust. The common carbonate minerals are calcium carbonate (calcite, aragonite, depending on its crystal structure), magnesium carbonate (magnesite), calcium-magnesium carbonate (dolomite), and barium carbonate (barite). A large amount of calcite can be found in many places in Indonesia such as Padalarang, Sukabumi, and Tasikmalaya (West Java Provence). Dolomite can be found in a large amount in Gresik, Lamongan, and Tuban (East Java Provence). Magnesite is quite rare in Indonesia, and up to the recent years it can only be found in Padamarang Island (South East Sulawesi Provence). The carbonate has been being exploited through open pit mining activity. Traditionally, calcite can be ground to produce material for brick production, be carved to produce craft product, or be roasted to produce lime for many applications such as raw materials for cement, flux for metal smelting, etc. Meanwhile, dolomite has traditionally been used as a raw material to make brick for local buildings and to make fertilizer for coconut oil plant. Carbonate minerals actually consist of important elements needed by modern application. Calcium is one of the elements needed in artificial bone formation, slow release fertilizer synthesis, dielectric material production, etc. Magnesium is an important material in automotive industry to produce the alloy for vehicle main parts. It is also used as alloying element in the production of special steel for special purpose. Magnesium oxide can be used to produce slow release fertilizer, catalyst and any other modern applications. The aim of this review article is to present in brief the recent technology in processing carbonate minerals. This review covers both the technology that has been industrially proven and the technology that is still in research and development stage. One of the industrially proven technologies to process carbonate mineral is

  4. Seasonal Cyclicity in Trace Elements and Stable Isotopes of Modern Horse Enamel.

    Directory of Open Access Journals (Sweden)

    Niels J de Winter

    Full Text Available The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared with trace element profiles measured using laboratory micro X-Ray Fluorescence scanning. Using known patterns of tooth eruption and the relationship between stable oxygen isotopes and local temperature seasonality, an age model is constructed that links records from six cheek upper right teeth from the second premolar to the third molar. When plotted on this age model, the trace element ratios from horse tooth enamel show a seasonal pattern with a small shift in phase compared to stable oxygen isotope ratios. While stable oxygen and carbon isotopes in tooth enamel are forced respectively by the state of the hydrological cycle and the animal's diet, we argue that the seasonal signal in trace elements reflects seasonal changes in dust intake and diet of the animal. The latter explanation is in agreement with seasonal changes observed in carbon isotopes of the same teeth. This external forcing of trace element composition in mammal tooth enamel implies that trace element ratios may be used as proxies for seasonal changes in paleo-environment and paleo-diet.

  5. The NA50 segmented target and vertex recognition system

    International Nuclear Information System (INIS)

    Bellaiche, F.; Cheynis, B.; Contardo, D.; Drapier, O.; Grossiord, J.Y.; Guichard, A.; Haroutunian, R.; Jacquin, M.; Ohlsson-Malek, F.; Pizzi, J.R.

    1997-01-01

    The NA50 segmented target and vertex recognition system is described. The segmented target consists of 7 sub-targets of 1-2 mm thickness. The vertex recognition system used to determine the sub-target where an interaction has occured is based upon quartz elements which produce Cerenkov light when traversed by charged particles from the interaction. The geometrical arrangement of the quartz elements has been optimized for vertex recognition in 208 Pb-Pb collisions at 158 GeV/nucleon. A simple algorithm provides a vertex recognition efficiency of better than 85% for dimuon trigger events collected with a 1 mm sub-target set-up. A method for recognizing interactions of projectile fragments (nuclei and/or groups of nucleons) is presented. The segmented target allows a large target thickness which together with a high beam intensity (∼10 7 ions/s) enables high statistics measurements. (orig.)

  6. Uptake of dissolved organic carbon and trace elements by zebra mussels

    Science.gov (United States)

    Roditi, Hudson A.; Fisher, Nicholas S.; Sañudo-Wilhelmy, Sergio A.

    2000-09-01

    Zebra mussels (Dreissena polymorpha) are widespread and abundant in major freshwater ecosystems in North America, even though the phytoplankton food resources in some of these systems seem to be too low to sustain them. Because phytoplankton biomass is greatly depleted in ecosystems with large D. polymorpha populations and bacteria do not seem to be an important food source for this species, exploitation of alternative carbon sources may explain the unexpected success of D. polymorpha in such environments. Here we examine the possibility that absorption of dissolved organic carbon (DOC) from water could provide a nutritional supplement to zebra mussels. We find that mussels absorb 14C-labelled DOC produced by cultured diatoms with an efficiency of 0.23%; this indicates that DOC in natural waters could contribute up to 50% of the carbon demand of zebra mussels. We also find that zebra mussels absorb some dissolved metals that have been complexed by the DOM; although absorption of dissolved selenium was unaffected by DOC, absorption of dissolved cadmium, silver and mercury by the mussels increased 32-, 8.7- and 3.6-fold, respectively, in the presence of high-molecular-weight DOC.

  7. International Nuclear Target Development Society workshop 1983: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G. (ed.)

    1983-01-01

    Separate abstracts were prepared for 11 of the 19 papers presented. Eight papers were previously included in the data base. Discussion group session papers on carbon stripper foils, problems in producing heavy-ion targets, and problems in producing general type targets are included. (WHK)

  8. Trace element measurements with synchrotron radiation

    International Nuclear Information System (INIS)

    Hanson, A.L.; Kraner, H.W.; Jones, K.W.; Gordon, B.M.; Mills, R.E.

    1982-01-01

    Aspects of the application of synchrotron radiation to trace element determinations by x-ray fluorescence have been investigated using beams from the Cornell facility, CHESS. Fluoresced x rays were detected with a Si(Li) detector placed 4 cm from the target at 90 0 to the beam. Thick samples of NBS Standard Reference Materials were used to calibrate trace element sensitivity and estimate minimum detectable limits for this method

  9. Dwarf carbon stars are likely metal-poor binaries and unlikely hosts to carbon planets

    Science.gov (United States)

    Whitehouse, Lewis J.; Farihi, J.; Green, P. J.; Wilson, T. G.; Subasavage, J. P.

    2018-06-01

    Dwarf carbon stars make up the largest fraction of carbon stars in the Galaxy with ≈1200 candidates known to date primarily from the Sloan Digital Sky Survey. They either possess primordial carbon-enhancements, or are polluted by mass transfer from an evolved companion such that C/O is enhanced beyond unity. To directly test the binary hypothesis, a radial velocity monitoring survey has been carried out on 28 dwarf carbon stars, resulting in the detection of variations in 21 targets. Using Monte Carlo simulations,this detection fraction is found to be consistent with a 100% binary population and orbital periods on the order of hundreds of days. This result supports the post-mass transfer nature of dwarf carbon stars, and implies they are not likely hosts to carbon planets.

  10. Purity of targets prepared on Cu substrates

    Science.gov (United States)

    Méens, A.; Rossini, I.; Sens, J. C.

    1993-09-01

    The purity of several elemental self-supporting targets usually prepared by evaporation onto soluble Cu substrates has been studied. The targets were analysed by Rutherford backscattering and instrumental neutron activation analysis. Because of the high percentage of Cu observed in some Si targets, further measurements, including transmission electron microscopy, have been performed on Si targets deposited by e-gun bombardment onto Cu and ion-beam sputtering onto betaine.

  11. Carbon nanotubes allow capture of krypton, barium and lead for multichannel biological X-ray fluorescence imaging.

    Science.gov (United States)

    Serpell, Christopher J; Rutte, Reida N; Geraki, Kalotina; Pach, Elzbieta; Martincic, Markus; Kierkowicz, Magdalena; De Munari, Sonia; Wals, Kim; Raj, Ritu; Ballesteros, Belén; Tobias, Gerard; Anthony, Daniel C; Davis, Benjamin G

    2016-10-26

    The desire to study biology in situ has been aided by many imaging techniques. Among these, X-ray fluorescence (XRF) mapping permits observation of elemental distributions in a multichannel manner. However, XRF imaging is underused, in part, because of the difficulty in interpreting maps without an underlying cellular 'blueprint'; this could be supplied using contrast agents. Carbon nanotubes (CNTs) can be filled with a wide range of inorganic materials, and thus can be used as 'contrast agents' if biologically absent elements are encapsulated. Here we show that sealed single-walled CNTs filled with lead, barium and even krypton can be produced, and externally decorated with peptides to provide affinity for sub-cellular targets. The agents are able to highlight specific organelles in multiplexed XRF mapping, and are, in principle, a general and versatile tool for this, and other modes of biological imaging.

  12. Simultaneous characterization of elemental segregation and cementite networks in high carbon steel products by spatially-resolved laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Boué-Bigne, Fabienne, E-mail: fabienne.boue-bigne@tatasteel.com

    2014-06-01

    The reliable characterization of the level of elemental segregation and of the extent of grain-boundary cementite networks in high carbon steel products is a prerequisite for checking product quality, for the purpose of product release to customers, and to investigate the presence of defects that may have led to mechanical property failure of the product. Current methods for the characterization of segregation and cementite networks rely on two different methods of sample etching followed by visual observation, where quality scores are given based on human perception and judgment. With the continuous demand on increasing quality, some of the conventional characterization methods and their associated scoring boards have lost relevance for the precision of characterization that is required today to distinguish between a product that will perform well and one that will not. In order to move away from a qualitative, human perception based situation for the scoring of the severity of segregation and cementite networks, a new method of data evaluation based on spatially-resolved LIBS measurements was developed to provide quantitative and simultaneous characterization of both types of defects. The quantitative assessment of segregation and cementite networks is based on the acquisition of carbon concentration maps. The ability to produce rapid scanning measurements of micro and macro-scale features with adequate spatial resolution makes LIBS the measurement method of preference for this purpose. The characterization of both different defects is extracted simultaneously and from the same carbon concentration map following a series of statistical treatment and data extraction rules. LIBS results were validated against recognized methods and were applied to a significant number of routine samples. The new LIBS method offers a step change improvement in reliability for the characterization of segregation and cementite networks in steel products over the conventional methods

  13. Chirality dependence of dipole matrix element of carbon nanotubes in axial magnetic field: A third neighbor tight binding approach

    Science.gov (United States)

    Chegel, Raad; Behzad, Somayeh

    2014-02-01

    We have studied the electronic structure and dipole matrix element, D, of carbon nanotubes (CNTs) under magnetic field, using the third nearest neighbor tight binding model. It is shown that the 1NN and 3NN-TB band structures show differences such as the spacing and mixing of neighbor subbands. Applying the magnetic field leads to breaking the degeneracy behavior in the D transitions and creates new allowed transitions corresponding to the band modifications. It is found that |D| is proportional to the inverse tube radius and chiral angle. Our numerical results show that amount of filed induced splitting for the first optical peak is proportional to the magnetic field by the splitting rate ν11. It is shown that ν11 changes linearly and parabolicly with the chiral angle and radius, respectively.

  14. The process of carbon creation

    CERN Multimedia

    El-Eid, M F

    2005-01-01

    In the Universe, the element carbon is created only in stars, in a remarkable reaction called the triple-α process. Fresh insights into the reaction now come from the latest experiments carried out on Earth

  15. Mixed Carbon Policies Based on Cooperation of Carbon Emission Reduction in Supply Chain

    Directory of Open Access Journals (Sweden)

    Yongwei Cheng

    2017-01-01

    Full Text Available This paper established cooperation decision model for a mixed carbon policy of carbon trading-carbon tax (environmental tax in a two-stage S-M supply chain. For three different cooperative abatement situations, we considered the supplier driven model, the manufacturer driven model, and the equilibrium game model. We investigated the influence of mixed carbon policy with constraint of reduction targets on supply chain price, productivity, profits, carbon emissions reduction rate, and so on. The results showed that (1 high-strength carbon policies do not necessarily encourage enterprises to effectively reduce emissions, and increasing market acceptance of low carbon products or raising the price of carbon quota can promote the benign reduction; (2 perfect competitive carbon market has a higher carbon reduction efficiency than oligarch carbon market, but their optimal level of cooperation is the same and the realized reduction rate is in line with the intensity of carbon policy; (3 the policy sensitivity of the carbon trading mechanism is stronger than the carbon tax; “paid quota mechanism” can subsidize the cost of abatement and improve reduction initiative. Finally, we use a numerical example to solve the optimal decisions under different market situations, validating the effectiveness of model and the conclusions.

  16. An evaluation of microwave-assisted fusion and microwave-assisted acid digestion methods for determining elemental impurities in carbon nanostructures using inductively coupled plasma optical emission spectrometry

    KAUST Repository

    Patole, Shashikant P.; Simõ es, Filipa; Yapici, Tahir; Warsama, Bashir H.; Anjum, Dalaver H.; Da Costa, Pedro M. F. J.

    2015-01-01

    A method for the complete digestion of carbon nanostructures has been demonstrated. Photographs (on the left side) show zirconium crucibles containing SWCNTs with flux of Na2CO3 and K2CO3, before and after microwave fusion; (on the right side) the appearance of the final solutions containing dissolved samples, from microwave-assisted fusion and microwave-assisted acid digestion. These solutions were used for determining the trace elemental impurities by ICP‒OES.

  17. Micro glow plasma for localized nanostructural modification of carbon nanotube forest

    Energy Technology Data Exchange (ETDEWEB)

    Sarwar, Mirza Saquib us; Xiao, Zhiming; Saleh, Tanveer; Nojeh, Alireza; Takahata, Kenichi [University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada)

    2016-08-22

    This paper reports the localized selective treatment of vertically aligned carbon nanotubes, or CNT forests, for radial size modification of the nanotubes through a micro-scale glow plasma established on the material. An atmospheric-pressure DC glow plasma is shown to be stably sustained on the surface of the CNT forest in argon using micromachined tungsten electrodes with diameters down to 100 μm. Experiments reveal thinning or thickening of the nanotubes under the micro glow depending on the process conditions including discharge current and process time. These thinning and thickening effects in the treated nanotubes are measured to be up to ∼30% and ∼300% in their diameter, respectively, under the tested conditions. The elemental and Raman analyses suggest that the treated region of the CNT forest is pure carbon and maintains a degree of crystallinity. The local plasma treatment process investigated may allow modification of material characteristics in different domains for targeted regions or patterns, potentially aiding custom design of micro-electro-mechanical systems and other emerging devices enabled by the CNT forest.

  18. Mass, black carbon and elemental composition of PM{sub 2.5} at an industrial site in Kingston, Jamaica

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Johan, E-mail: johan.boman@chem.gu.se; Gaita, Samuel M.

    2015-11-15

    An estimated three million premature deaths yearly can be attributed to ambient particulate pollution, a majority of them in low and middle income countries. The rapid increase in the vehicle fleet in urban areas of the Caribbean countries have experienced contributes to the bad urban air quality. In this study aerosol particles with an aerodynamic diameter smaller than, or equal to, 2.5 μm (PM{sub 2.5}) were collected over 24 h at a site along Spanish Town Road, one of the main commuter roads in Kingston, Jamaica. The study was aimed at determining the mass, black carbon and elemental composition of PM{sub 2.5} in Kingston. Although lead in the gasoline was phased out in the year 2000, up to 5000 ppm of sulfur is still allowed in the diesel, leading to an extensive secondary particle formation. PM{sub 2.5} samples were collected using a Mini-vol sampler between 12 December 2013 and 21 March 2014 and analyzed for trace elements using the Particle-Induced X-ray Emission (PIXE) facility at Lund University, Sweden. Concentrations of Si, S, Cl, K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Br and Pb were determined. Elemental concentrations showed a high temporal variation and the average PM{sub 2.5} concentration (44 μg m{sup −3}) is higher than the air quality standards that apply in the European Union (25 μg m{sup −3}) and in the USA (12 μg m{sup −3}). From this we can conclude that the air quality in the area is severely influenced by PM{sub 2.5} pollution and that there is a need to develop plans for improving the air quality in Kingston city.

  19. The Diversity of Carbon in Cometary Refractory Dust Particles

    Science.gov (United States)

    Wooden, D. H.

    2018-01-01

    When comparing the dark icy surfaces of outer solar system small bodies and the composition of carbonaceous chondrites derived from dark asteroids we find a significant discrepancy in the assessed amounts of elemental carbon: up to 80% amorphous carbon is used to model the dark surfaces of Kuiper Belt Objects and Centaurs whereas at most 5% of elemental carbon is found in carbonaceous chondrites. If we presume that regimes of comet nuclei formation are analogous to disk regimes where other outer solar system ice-rich bodies formed then we can turn to comet dust to gain insights into the diversity in the concentration and forms of carbon available in the outer disk. Comet dust offers important insights into the diversity in the amounts and forms of carbon that were incorporated into aggregate dust particles in the colder parts of the protoplanetary disk out of which comet nuclei accreted. Comet nuclei are amongst the most primitive bodies because they have remained cold and unequilibrated. Comet dust particles reveal the presence of forms of elemental carbon and of soluble and insoluble organic matter, and in a great diversity of concentrations from very little, e.g., Stardust samples of comet 81P/Wild 2, to 80% by volume for Ultra Carbonaceous Antarctic Micro Meteorites (UCAMMs). Cometary outbursts and/or jet activity also demonstrate variations in the concentration of carbon in the grains at different grain sizes within a single comet. We review the diversity of carbon-bearing dust grains in cometary samples, flyby measurements and deduced from remote-sensing to enrich the discussion about the diversity of carbonaceous matter available in the outer ice-rich disk at the time of comet nuclei formation.

  20. Enrichment of yttrium from rare earth concentrate by ammonium carbonate leaching and peroxide precipitation

    International Nuclear Information System (INIS)

    Vasconcellos, Mari E. de; Rocha, S.M.R. da; Pedreira, W.R.; Queiroz S, Carlos A. da; Abrao, Alcidio

    2006-01-01

    The rare earth elements (REE) solubility with ammonium carbonate vary progressively from element to element, the heavy rare earth elements (HRE) being more soluble than the light rare earth elements (LRE). Their solubility is function of the carbonate concentration and the kind of carbonate as sodium, potassium and ammonium. In this work, it is explored this ability of the carbonate for the dissolution of the REE and an easy separation of yttrium was achieved using the precipitation of the peroxide from complex yttrium carbonate. For this work is used a REE concentrate containing (%) Y 2 O 3 2.4, Dy 2 O 3 0.6, Gd 2 O 3 2.7, CeO 2 2.5, Nd 2 O 3 33.2, La 2 O 3 40.3, Sm 2 O 3 4.1 and Pr 6 O 11 7.5. The mentioned concentrate was produced industrially from the chemical treatment of monazite sand by NUCLEMON in Sao Paulo. The yttrium concentrate was treated with 200 g L -1 ammonium carbonate during 10 and 30 min at room temperature. The experiments indicated that a single leaching operation was sufficient to get a rich yttrium solution with about 60.3% Y 2 O 3 . In a second step, this yttrium solution was treated with an excess of hydrogen peroxide (130 volumes), cerium, praseodymium and neodymium peroxides being completely precipitated and separated from yttrium. Yttrium was recovered from the carbonate solution as the oxalate and finally as oxide. The final product is an 81% Y 2 O 3 . This separation envisages an industrial application. The work discussed the solubility of the REE using ammonium carbonate and the subsequent precipitation of the correspondent peroxides

  1. Emission of low-energetic electrons in collisions of heavy ions with solid targets

    International Nuclear Information System (INIS)

    Lineva, Natallia

    2008-07-01

    At the UNILAC accelerator, we have initiated a project with the objective to investigate lowenergy electrons, emitted from solid, electrically conductive targets after the impact of swift light and heavy ions. For this purposes, we have installed, optimized, and put into operation an electrostatic toroidal electron spectrometer. First, investigations of electrons, emitted from solid-state targets after the bombardment with a monochromatic electron beam from an electron gun, has been carried out. The proposed method combines the results of the measurements with the results of dedicated Monte Carlo simulations. The method has been elaborated in a case study for carbon targets. The findings have been instrumental for the interpretation of our measurements of electrons emitted in collisions of swift ions with the same carbon targets. Our investigations focused on following ion beams: protons and (H + 3 )-molecules of the same energy, as well as on carbon ions with two different energies. Thin carbon, nickel, argon and gold foils has been used as targets. Electrons in the energy range between 50 eV and 1 keV have been investigated. The measured electron distributions, both integral as well as differential with respect to the polar angle, have been compared to simple standard theories for gases as well as to the results of TRAX simulations, the latter being based on data from gaseous targets. Dedicated TRAX simulations have been performed only for the carbon targets, applying the method mentioned above. Within our experimental uncertainties, we observe a good agreement of the measured and TRAX simulated data. That leads us to the conclusion that - as a first order approximation - the electron emission pattern from ion-atom collisions in solid-state targets and the one from single collisions in gases are similar. (orig.)

  2. 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.

  3. A measuring system for the fast simultaneous isotope ratio and elemental analysis of carbon, hydrogen, nitrogen and sulfur in food commodities and other biological material.

    Science.gov (United States)

    Sieper, Hans-Peter; Kupka, Hans-Joachim; Williams, Tony; Rossmann, Andreas; Rummel, Susanne; Tanz, Nicole; Schmidt, Hanns-Ludwig

    2006-01-01

    The isotope ratio of each of the light elements preserves individual information on the origin and history of organic natural compounds. Therefore, a multi-element isotope ratio analysis is the most efficient means for the origin and authenticity assignment of food, and also for the solution of various problems in ecology, archaeology and criminology. Due to the extraordinary relative abundances of the elements hydrogen, carbon, nitrogen and sulfur in some biological material and to the need for individual sample preparations for H and S, their isotope ratio determination currently requires at least three independent procedures and approximately 1 h of work. We present here a system for the integrated elemental and isotope ratio analysis of all four elements in one sample within 20 min. The system consists of an elemental analyser coupled to an isotope ratio mass spectrometer with an inlet system for four reference gases (N(2), CO(2), H(2) and SO(2)). The combustion gases are separated by reversible adsorption and determined by a thermoconductivity detector; H(2)O is reduced to H(2). The analyser is able to combust samples with up to 100 mg of organic material, sufficient to analyse samples with even unusual elemental ratios, in one run. A comparison of the isotope ratios of samples of water, fruit juices, cheese and ethanol from wine, analysed by the four-element analyser and by classical methods and systems, respectively, yielded excellent agreements. The sensitivity of the device for the isotope ratio measurement of C and N corresponds to that of other systems. It is less by a factor of four for H and by a factor of two for S, and the error ranges are identical to those of other systems. Copyright (c) 2006 John Wiley & Sons, Ltd.

  4. Design of the target area for the National Ignition Facility

    International Nuclear Information System (INIS)

    Foley, R.J.; Karpenko, V.P.; Adams, C.H.

    1997-01-01

    The preliminary design of the target area for the National Ignition Facility has been completed. The target area is required to meet a challenging set of engineering system design requirements and user needs. The target area must provide the appropriate conditions before, during, and after each shot. The repeated introduction of large amounts of laser energy into the chamber and subsequent target emissions represent new design challenges for ICF facility design. Prior to each shot, the target area must provide the required target illumination, target chamber vacuum, diagnostics, and optically stable structures. During the shot, the impact of the target emissions on the target chamber, diagnostics, and optical elements is minimized and the workers and public are protected from excessive prompt radiation doses. After the shot, residual radioactivation is managed to allow the required accessibility. Diagnostic data is retrieved, operations and maintenance activities are conducted, and the facility is ready for the next shot. The target area subsystems include the target chamber, target positioner, structural systems, target diagnostics, environmental systems, and the final optics assembly. The engineering design of the major elements of the target area requires a unique combination of precision engineering, structural analysis, opto-mechanical design, random vibration suppression, thermal stability, materials engineering, robotics, and optical cleanliness. The facility has been designed to conduct both x- ray driven targets and to be converted at a later date for direct drive experiments. The NIF has been configured to provide a wide range of experimental environments for the anticipated user groups of the facility. The design status of the major elements of the target area is described

  5. Measurements of secondary neutrons producted from thick targets bombarded by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, T.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Nakao, N.; Shibata, T.; Uwamino, Y.; Nakanishi, N.; Fukumura, A.; Kumamoto, Y.

    1997-03-01

    We measured neutron angular and energy distributions from high energy heavy ions stopping in targets of carbon, aluminum, copper and lead at HIMAC. These spectra are much harder for the lighter target nucleus like carbon. This means that the momentum transfer in the forward direction from heavy ion beam to lighter nuclei is much higher than that to heavier nuclei. (author)

  6. Soil, climate and the environment - an indissociable threesome. Soil carbon and global changes: reciprocal impacts; Carbon in all its forms; Echomicadas, a new tool to analyse carbon 14; Biotransformation of metallic trace elements by soil micro-organisms; Absorption and distribution of metallic elements in plants; Dynamics of metallic contaminants in agricultural systems; Is photo-remediation for tomorrow? Hyper-accumulator plants; Sediments, tell me the Seine history... The complex history of plant feeding by the soil; The environmental analysis

    International Nuclear Information System (INIS)

    Hatte, Christine; Tisnerat-Laborde, Nadine; Ayrault, Sophie; Balesdent, Jerome; Chapon, Virginie; Bourguignon, Jacques; Alban, Claude; Ravanel, Stephane; Denaix, Laurence; Nguyen, Christophe; Vavasseur, Alain; Sarrobert, Catherine; Gasperi, Johnny; Latrille, Christelle; Savoye, Sebastien; Augusto, Laurent; Conan Labbe, Annie; Bernard Michel, Bruno; Douysset, Guilhem; Toqnelli, Antoine; Vailhen, Dominique; Moulin, Christophe

    2016-01-01

    The articles of this file on the relationships between soils, climate and the environment discuss the reciprocal impacts of soil carbon and global changes with the objective of reduction of greenhouse effect and of increase of carbon sequestration; the various forms of carbon are presented and their properties commented ; a compact radiocarbon system (ECHoMiCADAS) is presented, developed by the Laboratory of sciences of climate and environment (LSCE) and designed for the analysis of carbon 14; an article describes how micro-organisms can play a crucial role in the transformation of soil pollutants by modifying their chemical speciation and thus their toxicity; strategies based on the absorption of metallic trace elements present in the soil to control physiological processes in plants are discussed, with applications to agriculture, food supply and to the environment; researches related to the study of effects of metallic contaminants in agricultural systems are evoked, and the reasons for a slow development of phyto-technologies, notably phyto-remediation, for pollution control and decontamination of soils and liquid media, are explained. Other themes are presented : hyper-accumulator plants which present very high contents of non-essential (As, Cd, Hg, Pb, Se) or essential (Co, Cu, Fe, Mn, Mo, Ni) elements, are slowly growing, and display a limited biomass, but could be used for a phyto-extraction of metals from contaminated soils; how analysis and dating of sediments can reveal the presence of contaminants, and therefore give an insight into human activities and regulations, and into their impact on the river; how plants are able to develop strategies in their search for nutrients in different types of soils, even poor ones, and presentation of the various disciplines, methods and techniques used for environmental analysis with their applications to installation and site control, or to the study of pollutant migration

  7. Regional patterns of labile organic carbon flux in North American Arctic Margin (NAAM) as reflected by redox sensitive-elements distributions in sediments

    Science.gov (United States)

    Gobeil, C.; Kuzyk, Z. Z. A.; Goni, M. A.; Macdonald, R. W.

    2016-02-01

    Concentrations of elements (S, Mn, Mo, U, Cd, Re) providing insights on organic C metabolized through oxidative processes at the sea floor were measured in 27 sediment cores collected along a section extending from the North Bering Sea to Davis Strait via the Canadian Archipelago. Sedimentary distributions and accumulation rates of these elements were used to i) document the relative importance of aerobic versus anaerobic degradation of organic C in NAAM sediments, ii) infer variations in water column carbon flux and iii) estimate the importance of this margin as a sink for key elements in the Arctic and global ocean. Distributions of Mn, total S and reduced inorganic S demonstrated that most sediments along the NAAM had relatively thick (>1 cm) surface oxic layers, underlain by sediments with weakly reducing conditions and limited sulphate reduction. Strongly reducing conditions accompanied by substantial sedimentary pyrite burial occurred only in certain subregions, including the Bering-Chukchi Shelves, shallow portions of Barrow Canyon. Estimated accumulation rates of authigenic S, Mo, Cd and U, and total Re displayed marked spatial variability that was related to sedimentary redox conditions induced by the supply of labile C to the seabed, as shown by significant relationships between the accumulation rates and vertical C flux, estimated from regional primary production values and water depth at the coring sites. High primary production combined with shallow water columns drive elevated rates of authigenic trace element accumulation in sediments from the Bering-Chukchi Shelves whereas low production combined with moderately deep conditions drive low rates of accumulation in sediments in the Beaufort Shelf, Davis Strait and Canadian Archipelago. Using the average authigenic trace element accumulation rates in sediments from the various regions, we submit that the shelves along the NAAM margin are important sinks in global marine biogeochemical budgets.

  8. Experimental and numerical simulation of carbon manganese steel ...

    African Journals Online (AJOL)

    Experimental and numerical simulation of carbon manganese steel for cyclic plastic behaviour. J Shit, S Dhar, S Acharyya. Abstract. The paper deals with finite element modeling of saturated low cycle fatigue and the cyclic hardening phenomena of the materials Sa333 grade 6 carbon steel and SS316 stainless steel.

  9. Contribution to the analysis of light elements using x fluorescence excited by radio-elements

    International Nuclear Information System (INIS)

    Robert, A.

    1964-01-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, β and α emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K α lines of 3. period elements excited by 55 Fe, 3 H/Zr and 210 Po sources; for the 2. period the K α spectra of carbon and of fluorine excited by the α particles of 210 Po. (author) [fr

  10. 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)

  11. 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)

  12. Do overarching mitigation objectives dominate transport-specific targets in the EU?

    International Nuclear Information System (INIS)

    Ghersi, Frédéric; McDonnell, Simon; Sassi, Olivier

    2013-01-01

    This research investigates if the stringent 2020 and 2050 overarching CO 2 mitigation objectives set out by the European Union dominate its 2010 to 2020 targets specific to the transportation arena, specifically its biofuel penetration objectives and gram CO 2 per kilometre emission caps. Using a dynamic recursive general equilibrium model, IMACLIM-R, we demonstrate that these overarching targets do not dominate the interim transportation targets when the carbon policy triggering compliance with the mitigation objectives boils down to the theoretical least-cost option of uniform carbon pricing. Ground transportation is confirmed as quite insensitive to high carbon prices, even when such prices are applied over a long term. It is tempting to conclude that pursuing the mitigation objectives specific to transportation will impose unnecessary costs. However, because of the second best conditions prevailing in actual economies, and of the risk of lock-in in carbon intensive trajectories, we conclude with the urgent need for some ambitious transport-specific policy design research agenda. - Highlights: ► We review the European Union’s climate and transportation policy. ► We describe the IMACLIM-R model and how it represents transport. ► We develop an EU carbon pricing scenario that meets its aggregate CO 2 targets. ► This does not require meeting biofuel nor g/km 2010 to 2020 objectives. ► We conclude on the policy implications of this apparent inefficiency

  13. Chromatographic behavior of carbonate complexes of lanthanides and of thorium in alumina

    International Nuclear Information System (INIS)

    Tomida, E.K.

    1977-01-01

    The chromatographic behavior of some rare earth elements and thorium on alumina is studied in order to evaluate the possibility of separation from concentration of trace rare earths from high-purity thorium compounds. The effect of some factors on complex thorium carbonate formation and the extent of thorium solubility in sodium and potassium carbonate solutions investigated. The sorption of rare earth elements and thoriuum on alumina from alkali carbonate solution is observed, despite the reports that alumina acts as a cation exchanger in alkali media and that thorium and rare earths form stable anionic carbonate complexes. The formation of these elements between alumina and potassium carbonate solutions is studied as a function of pH, carbonate concentration and metal ion concentration. Also the elution of rare earths from alumina is studied and the best results are obtained with mineral acids and EDTA plus alkali carbonate solutions. The effect of some parameters as column aging, mixed solvents, column treatment with organic solvents, temperature, aluant concentration is investigated. Attempting to understand this sorption mechanism, some experiments with strongly basic anion exchanger and cation exchangers of strongly acid and weakly acid type are accomplished. It is observed that there are significant differences, in some conditions, between the behavior of rare earths and of thorium, pointing our the possibility of separation of one lanthanide from others and of these from thorium [pt

  14. Polycyclic aromatic hydrocarbons (PAH) and diesel engine emission (elemental carbon) inside a car and a subway train.

    Science.gov (United States)

    Fromme, H; Oddoy, A; Piloty, M; Krause, M; Lahrz, T

    1998-06-30

    Significant concentrations of potentially harmful substances can be present in the interior of vehicles. The main sources of PAHs and elemental carbon (EC) inside a car are likely to be combustion emissions, especially from coal and traffic. The same sources can also be important for the interior of a subway train for which there are specific sources in the tunnel system, for example diesel engines. Twice, in summer 1995 and winter 1996 polycyclic aromatic hydrocarbons (PAH) and diesel motor emission (estimated as elemental carbon) were determined in the interior of a car (a 2-year-old VW Golf with a three-way catalytic converter) and in the passenger compartment of a subway train (below ground). On each sampling day (in total 16 daily measurements in the car and 16 in the subway) the substances were determined in the breathing zone of the passengers from 07:00 h to 16:00 h under different meteorologic conditions (winter- and summertime). The car followed the route of the subway from the western Berlin borough of Spandau to the south-eastern borough of Neukölln, and back. The sampling represented a realistic exposure model for driving in a high traffic and polluted urban area. The electric subway train (also 2 years in use) connected the same parts of Berlin (31 km underground). The mean values obtained during the two measurement periods (summer/winter) inside the car were 1.0 and 3.2 ng/m3 for benzo[a]pyrene, 10.2 and 28.7 ng/m3 for total-measured-PAHs, 14.1 and 8.2 micrograms/m3 for EC and in the subway 0.7 and 4.0 ng/m3 for benzol[a]pyrene, 30.2 and 67.5 ng/m3 for total PAHs, 109 and 6.9 micrograms/m3 for EC. A comparison between subway and car exposures shows significantly higher concentrations of PAHs in the subway train, which can be explained by relatively high concentrations of fluoranthene and pyrene in the subway. So far a satisfactory explanation has not been found, but one source might be the wooden railway ties which were formerly preserved with tar

  15. Qualification of high heat flux components: application to target elements of W7-X divertor

    International Nuclear Information System (INIS)

    Missirlian, M; Durocher, A; Grosman, A; Schlosser, J; Boscary, J; Escourbiac, F; Cismondi, F

    2007-01-01

    The development of actively cooled plasma-facing components (PFC) represents one of fusion's most challenging engineering efforts. In this frame, a high-quality bonding between the refractory armour and the heat sink is essential to ensure the heat removal capability and the thermal performances of PFC. Experience gained during manufacturing of Tore Supra actively cooled PFC led to the establishment of a qualification methodology and provided a large experience of acceptance criteria using an active infrared thermography (systeme d'acquisition de traitement infra-rouge, SATIR). This paper presents the application of this qualification process to the W7-X pre-series components, with the objective of assessing and defining workable acceptance criteria that enable reliable predictions of performance at the nominal heat flux requirements in W7-X. Finally, to check the reliability of the non-destructive examination (NDE) method by transient infrared thermography, the newly defined acceptance criteria were applied to W7-X pre-series target elements (batch no. 3). The SATIR results, benchmarked with HHF tests performed on the GLADIS ion beam facility were discussed to assess the ability to detect critical defects at the interface between tiles and heat sink

  16. Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

    International Nuclear Information System (INIS)

    Poudel, P.R.; Poudel, P.P.; Paramo, J.A.; Strzhemechny, Y.M.; Rout, B.; McDaniel, F.D.

    2015-01-01

    The structural and optical properties of carbon nanoclusters formed in thermally grown silicon dioxide film via the ion beam synthesis process have been investigated. A low-energy (70 keV) carbon ion beam (C - ) at a fluence of 3 x 10 17 atoms/cm 2 was used for implantation into a thermally grown silicon dioxide layer (500 nm thick) on a Si (100) wafer. Several parts of the implanted samples were subsequently annealed in a gas mixture (4 % H 2 + 96 % Ar) at 900 C for different time periods. The as-implanted and annealed samples were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL). The carbon ion implantation depth profile was simulated using a widely used Monte Carlo-based simulation code SRIM-2012. Additionally, the elemental depth profile of the implanted carbon along with host elements of silicon and oxygen were simulated using a dynamic ion-solid interaction code T-DYN, which incorporates the effects of the surface sputtering and gradual change in the elemental composition in the implanted layers due to high-fluence ion implantation. The elemental depth profile obtained from the XPS measurements matches closely to the T-DYN predictions. Raman measurements indicate the formation of graphitic phases in the annealed samples. The graphitic peak (G-peak) was found to be increased with the annealing time duration. In the sample annealed for 10 min, the sizes of the carbon nanoclusters were found to be 1-4 nm in diameter using TEM. The PL measurements at room temperature using a 325-nm laser show broad-band emissions in the ultraviolet to visible range in the as-implanted sample. Intense narrow bands along with the broad bands were observed in the annealed samples. The defects present in the as-grown samples along with carbon ion-induced defect centers in the as-implanted samples are the main contributors to the observed

  17. Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Poudel, P.R. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States); Intel Corporation, Rio Rancho, NM (United States); Poudel, P.P. [University of Kentucky, Department of Chemistry, Lexington, KY (United States); Paramo, J.A.; Strzhemechny, Y.M. [Texas Christian University, Department of Physics and Astronomy, Fort Worth, TX (United States); Rout, B. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States); University of North Texas, Center for Advanced Research and Technology, Denton, TX (United States); McDaniel, F.D. [University of North Texas, Ion Beam Modification and Analysis Laboratory, Department of Physics, Denton, TX (United States)

    2014-09-18

    The structural and optical properties of carbon nanoclusters formed in thermally grown silicon dioxide film via the ion beam synthesis process have been investigated. A low-energy (70 keV) carbon ion beam (C{sup -}) at a fluence of 3 x 10{sup 17} atoms/cm{sup 2} was used for implantation into a thermally grown silicon dioxide layer (500 nm thick) on a Si (100) wafer. Several parts of the implanted samples were subsequently annealed in a gas mixture (4 % H{sub 2} + 96 % Ar) at 900 C for different time periods. The as-implanted and annealed samples were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL). The carbon ion implantation depth profile was simulated using a widely used Monte Carlo-based simulation code SRIM-2012. Additionally, the elemental depth profile of the implanted carbon along with host elements of silicon and oxygen were simulated using a dynamic ion-solid interaction code T-DYN, which incorporates the effects of the surface sputtering and gradual change in the elemental composition in the implanted layers due to high-fluence ion implantation. The elemental depth profile obtained from the XPS measurements matches closely to the T-DYN predictions. Raman measurements indicate the formation of graphitic phases in the annealed samples. The graphitic peak (G-peak) was found to be increased with the annealing time duration. In the sample annealed for 10 min, the sizes of the carbon nanoclusters were found to be 1-4 nm in diameter using TEM. The PL measurements at room temperature using a 325-nm laser show broad-band emissions in the ultraviolet to visible range in the as-implanted sample. Intense narrow bands along with the broad bands were observed in the annealed samples. The defects present in the as-grown samples along with carbon ion-induced defect centers in the as-implanted samples are the main

  18. Carbon allocation, source-sink relations and plant growth: do we need to revise our carbon centric concepts?

    Science.gov (United States)

    Körner, Christian

    2014-05-01

    Since the discovery that plants 'eat air' 215 years ago, carbon supply was considered the largely unquestioned top driver of plant growth. The ease at which CO2 uptake (C source activity) can be measured, and the elegant algorithms that describe the responses of photosynthesis to light, temperature and CO2 concentration, explain why carbon driven growth and productivity became the starting point of all process based vegetation models. Most of these models, nowadays adopt other environmental drivers, such as nutrient availability, as modulating co-controls, but the carbon priority is retained. Yet, if we believe in the basic rules of stoichometry of all life, there is an inevitable need of 25-30 elements other then carbon, oxygen and hydrogen to build a healthy plant body. Plants compete for most of these elements, and their availability (except for N) is finite per unit land area. Hence, by pure plausibility, it is a highly unlikely situation that carbon plays the rate limiting role of growth under natural conditions, except in deep shade or on exceptionally fertile soils. Furthermore, water shortage and low temperature, both act directly upon tissue formation (meristems) long before photosynthetic limitations come into play. Hence, plants will incorporate C only to the extent other environmental drivers permit. In the case of nutrients and mature ecosystems, this sink control of plant growth may be masked in the short term by a tight, almost closed nutrient cycle or by widening the C to other element ratio. Because source and sink activity must match in the long term, it is not possible to identify the hierarchy of growth controls without manipulating the environment. Dry matter allocation to C rich structures and reserves may provide some stoichimetric leeway or periodic escapes from the more fundamental, long-term environmental controls of growth and productivity. I will explain why carbon centric explanations of growth are limited or arrive at plausible answers

  19. Ocean carbon uptake and storage

    International Nuclear Information System (INIS)

    Tilbrook, Bronte

    2007-01-01

    Full text: The ocean contains about 95% of the carbon in the atmosphere, ocean and land biosphere system, and is of fundamental importance in regulating atmospheric carbon dioxide concentrations. In the 1990s an international research effort involving Australia was established to determine the uptake and storage of anthropogenic C02 for all major ocean basins. The research showed that about 118 of the 244 + 20 billion tons of the anthropogenic carbon emitted through fossil fuel burning and cement production has been stored in the ocean since preindustrial times, thus helping reduce the rate of increase in atmospheric C02. The research also showed the terrestrial biosphere has been a small net source of C02 (39 ± 28 billion tons carbon) to the atmosphere over the same period. About 60% of the total ocean inventory of the anthropogenic C02 was found in the Southern Hemisphere, with most in the 30 0 S to 50 0 S latitude band. This mid-latitude band is where surface waters are subducted as Mode and Intermediate waters, which is a major pathway controlling ocean C02 uptake. High storage (23% of the total) also occurs in the North Atlantic, associated with deep water formation in that basin. The ocean uptake and storage is expected to increase in the coming decades as atmospheric C02 concentrations rise. However, a number of feedback mechanisms associated with surface warming, changes in circulation, and biological effects are likely to impact on the uptake capacity. The accumulation or storage-of the C02 in the ocean is also the major driver of ocean acidification with potential to disrupt marine ecosystems. This talk will describe the current understanding of the ocean C02 uptake and storage and a new international research strategy to detect how the ocean uptake and storage will evolve on interannual through decadal scales. Understanding the ocean response to increasing atmospheric C02 will be a key element in managing future C02 increases and establishing

  20. Development of a dry-mechanical graphite separation process and elimination of the separated carbon for the reprocessing of spherical HTR fuel elements

    International Nuclear Information System (INIS)

    Kronschnabel, H.

    1982-01-01

    Due to the C-14 distribution the separation of the particle-free outer region of the spherical HTR fuel element with subsequent solidification of the separated carbon makes it possible to reduce by half the remaining C-14 inventory in the inner particle region to be further treated. Separation of the particle-free outer region by a newly developed sphere-peeling milling machine, conditioning the graphite into compacts and in-situ cementation into a salt-mine are the basic elements of this head-end process variation. An annual cavern volume of approx. 2000 m 3 will be needed to ultimately store the graphite of the particle-free outer region, which corresponds to a reprocessing capacity of 50 GWsub(e) installed HTR power. The brush-disintegration of the remaining inner particle region and the resulting peel-brush-preparation are capable of separating 95% of the graphite without any heavy metal losses. With the mentioned reprocessing capacity an annual cavern volume of approx. 16.500 m 3 is required. (orig.) [de

  1. Antisense targeting of 3' end elements involved in DUX4 mRNA processing is an efficient therapeutic strategy for facioscapulohumeral dystrophy: a new gene-silencing approach.

    Science.gov (United States)

    Marsollier, Anne-Charlotte; Ciszewski, Lukasz; Mariot, Virginie; Popplewell, Linda; Voit, Thomas; Dickson, George; Dumonceaux, Julie

    2016-04-15

    Defects in mRNA 3'end formation have been described to alter transcription termination, transport of the mRNA from the nucleus to the cytoplasm, stability of the mRNA and translation efficiency. Therefore, inhibition of polyadenylation may lead to gene silencing. Here, we choose facioscapulohumeral dystrophy (FSHD) as a model to determine whether or not targeting key 3' end elements involved in mRNA processing using antisense oligonucleotide drugs can be used as a strategy for gene silencing within a potentially therapeutic context. FSHD is a gain-of-function disease characterized by the aberrant expression of the Double homeobox 4 (DUX4) transcription factor leading to altered pathogenic deregulation of multiple genes in muscles. Here, we demonstrate that targeting either the mRNA polyadenylation signal and/or cleavage site is an efficient strategy to down-regulate DUX4 expression and to decrease the abnormally high-pathological expression of genes downstream of DUX4. We conclude that targeting key functional 3' end elements involved in pre-mRNA to mRNA maturation with antisense drugs can lead to efficient gene silencing and is thus a potentially effective therapeutic strategy for at least FSHD. Moreover, polyadenylation is a crucial step in the maturation of almost all eukaryotic mRNAs, and thus all mRNAs are virtually eligible for this antisense-mediated knockdown strategy. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. 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.

  3. Production of atomic negative ion beams of the Group IA elements

    International Nuclear Information System (INIS)

    Alton, G.D.; Mills, G.D.

    1988-01-01

    A method has been developed which enables the direct sputter generation of atomic negative ion beams of all members of the Group IA elements (Li, Na, K, Rb, and Cs). The method consists of the use of sputter samples formed by pressing mixtures of the carbonates of the Group IA elements and 10% (atomic) Cu, Ag, or other metal powder. The following intensities are typical of those observed from carbonate samples subjected to /approximately/3 KeV cesium ion bombardment: Li - : ≥0.5 μA; Na - : ≥0.5 μA; K - : ≥0.5 μA; Rb - : ≥0.5 μA; Cs - : ≥0.2 μA. 7 refs., 2 figs., 1 tab

  4. Targeted gene insertion for molecular medicine.

    Science.gov (United States)

    Voigt, Katrin; Izsvák, Zsuzsanna; Ivics, Zoltán

    2008-11-01

    Genomic insertion of a functional gene together with suitable transcriptional regulatory elements is often required for long-term therapeutical benefit in gene therapy for several genetic diseases. A variety of integrating vectors for gene delivery exist. Some of them exhibit random genomic integration, whereas others have integration preferences based on attributes of the targeted site, such as primary DNA sequence and physical structure of the DNA, or through tethering to certain DNA sequences by host-encoded cellular factors. Uncontrolled genomic insertion bears the risk of the transgene being silenced due to chromosomal position effects, and can lead to genotoxic effects due to mutagenesis of cellular genes. None of the vector systems currently used in either preclinical experiments or clinical trials displays sufficient preferences for target DNA sequences that would ensure appropriate and reliable expression of the transgene and simultaneously prevent hazardous side effects. We review in this paper the advantages and disadvantages of both viral and non-viral gene delivery technologies, discuss mechanisms of target site selection of integrating genetic elements (viruses and transposons), and suggest distinct molecular strategies for targeted gene delivery.

  5. 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.

  6. A Three End-Member Mixing Model Based on Isotopic Composition and Elemental Ratio

    Directory of Open Access Journals (Sweden)

    Kon-Kee Liu Shuh-Ji Kao

    2007-01-01

    Full Text Available A three end-member mixing model based on nitrogen isotopic composition and organic carbon to nitrogen ratio of suspended particulate matter in an aquatic environment has been developed. Mathematical expressions have been derived for the calculation of the fractions of nitrogen or organic carbon originating from three different sources of distinct isotopic and elemental compositions. The model was successfully applied to determine the contributions from anthropogenic wastes, soils and bedrock-derived sediments to particulate nitrogen and particulate organic carbon in the Danshuei River during the flood caused by Typhoon Bilis in August 2000. The model solutions have been expressed in a general form that allows applications to mixtures with other types of isotopic compositions and elemental ratios or in forms other than suspended particulate matter.

  7. Elemental and stable isotopic approaches for studying the organic and inorganic carbon components in natural samples

    International Nuclear Information System (INIS)

    Helie, J-F

    2009-01-01

    The carbon cycle is an important part of major biogeochemical cycles. Many techniques may be used to characterize carbon amounts and sources in the environment. Here we first review the most popular techniques for the determination of organic and inorganic carbon concentrations. Decarbonatation techniques are also reviewed in details since it is often an important part of organic carbon analysis. The second part of this paper addresses the use of carbon stable isotopes to characterize organic carbon sources and processes in the environment. An overview of general stable isotopes background and terminology is given as well as the most popular analytical techniques.

  8. "Hello, I'm Carbon.": Writing about Elements and Compounds

    Science.gov (United States)

    Stout, Roland P.

    2010-01-01

    General chemistry students are asked to assume the identity of an element and to write their own story. In the spirit of pedagogical approaches such as writing-to-learn and writing across the curriculum, this assignment has several objectives, most significantly to connect students to the discipline of chemistry in a robust way. Facilitating this…

  9. Proceedings of transuranium elements

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The identification of the first synthetic elements was established by chemical evidence. Conclusive proof of the synthesis of the first artificial element, technetium, was published in 1937 by Perrier and Segre. An essential aspect of their achievement was the prediction of the chemical properties of element 43, which had been missing from the periodic table and which was expected to have properties similar to those of manganese and rhenium. The discovery of other artificial elements, astatine and francium, was facilitated in 1939-1940 by the prediction of their chemical properties. A little more than 50 years ago, in the spring of 1940, Edwin McMillan and Philip Abelson synthesized element 93, neptunium, and confirmed its uniqueness by chemical means. On August 30, 1940, Glenn Seaborg, Arthur Wahl, and the late Joseph Kennedy began their neutron irradiations of uranium nitrate hexahydrate. A few months later they synthesized element 94, later named plutonium, by observing the alpha particles emitted from uranium oxide targets that had been bombarded with deuterons. Shortly thereafter they proved that is was the second transuranium element by establishing its unique oxidation-reduction behavior. The symposium honored the scientists and engineers whose vision and dedication led to the discovery of the transuranium elements and to the understanding of the influence of 5f electrons on their electronic structure and bonding. This volume represents a record of papers presented at the symposium

  10. Designer policy for carbon and biodiversity co-benefits under global change

    Science.gov (United States)

    Bryan, Brett A.; Runting, Rebecca K.; Capon, Tim; Perring, Michael P.; Cunningham, Shaun C.; Kragt, Marit E.; Nolan, Martin; Law, Elizabeth A.; Renwick, Anna R.; Eber, Sue; Christian, Rochelle; Wilson, Kerrie A.

    2016-03-01

    Carbon payments can help mitigate both climate change and biodiversity decline through the reforestation of agricultural land. However, to achieve biodiversity co-benefits, carbon payments often require support from other policy mechanisms such as regulation, targeting, and complementary incentives. We evaluated 14 policy mechanisms for supplying carbon and biodiversity co-benefits through reforestation of carbon plantings (CP) and environmental plantings (EP) in Australia’s 85.3 Mha agricultural land under global change. The reference policy--uniform payments (bidders are paid the same price) with land-use competition (both CP and EP eligible for payments), targeting carbon--achieved significant carbon sequestration but negligible biodiversity co-benefits. Land-use regulation (only EP eligible) and two additional incentives complementing the reference policy (biodiversity premium, carbon levy) increased biodiversity co-benefits, but mostly inefficiently. Discriminatory payments (bidders are paid their bid price) with land-use competition were efficient, and with multifunctional targeting of both carbon and biodiversity co-benefits increased the biodiversity co-benefits almost 100-fold. Our findings were robust to uncertainty in global outlook, and to key agricultural productivity and land-use adoption assumptions. The results suggest clear policy directions, but careful mechanism design will be key to realising these efficiencies in practice. Choices remain for society about the amount of carbon and biodiversity co-benefits desired, and the price it is prepared to pay for them.

  11. Carbon Reduction Strategies Based on an NW Small-World Network with a Progressive Carbon Tax

    Directory of Open Access Journals (Sweden)

    Bin Wu

    2017-09-01

    Full Text Available There is an increasingly urgent need to reduce carbon emissions. Devising effective carbon tax policies has become an important research topic. It is necessary to explore carbon reduction strategies based on the design of carbon tax elements. In this study, we explore the effect of a progressive carbon tax policy on carbon emission reductions using the logical deduction method. We apply experience-weighted attraction learning theory to construct an evolutionary game model for enterprises with different levels of energy consumption in an NW small-world network, and study their strategy choices when faced with a progressive carbon tax policy. The findings suggest that enterprises that adopt other energy consumption strategies gradually transform to a low energy consumption strategy, and that this trend eventually spreads to the entire system. With other conditions unchanged, the rate at which enterprises change to a low energy consumption strategy becomes faster as the discount coefficient, the network externality, and the expected adjustment factor increase. Conversely, the rate of change slows as the cost of converting to a low energy consumption strategy increases.

  12. Barriers and possibilities for low-carbon-energy consuming technologies

    DEFF Research Database (Denmark)

    Bjarklev, Araceli

    consensus that one of the solutions to the current environmental challenge will be based on low-carbon-technologies, there are many issues that set a barrier for its adequate development and still many actors in these sectors are sceptical about the possibilities. Illumination is a very interesting sector...... to target, since it uses 19% of the total electricity produced in the world. Consequently, this paper takes the Danish office lighting sector as a study object and discusses the question: What are the main barriers and possibilities for the energy saving illumination technologies to efficiently reduce...... their ecological footprint. The discussion is supported by using relevant elements of the cradle-to-grave, eco-design and environmental-innovation theories. It is based on active participation in interdisciplinary projects and face-to-face in-depth interviews with relevant actors along the entire Danish...

  13. Method for the irradiation of single targets

    International Nuclear Information System (INIS)

    Krimmel, E.; Dullnig, H.

    1977-01-01

    The invention pertains to a system for the irradiation of single targets with particle beams. The targets all have frames around them. The system consists of an automatic advance leading into a high-vacuum chamber, and a positioning element which guides one target after the other into the irradiation position, at right angles to the automatic advance, and back into the automatic advance after irradiation. (GSCH) [de

  14. The effect of carbon tax on carbon emission abatement and GDP: a case study

    Science.gov (United States)

    Liu, Xiao; Leung, Yee; Xu, Yuan; Yung, Linda Chor Wing

    2017-10-01

    Carbon tax has been advocated as an effective economic instrument for the abatement of CO2 emission by various countries, including China, the world's biggest carbon emission country. However, carbon emission abatement cannot be done while ignoring the impact on economic growth. A delicate balance needs to be achieved between the two to find an appropriate pathway for sustainable development. This paper applies a multi-objective optimization approach to analyze the impact of levying carbon tax on the energy-intensive sectors of Guangdong province in China under the constraint of emission reduction target. This approach allows us to evaluate carbon emission minimization while maximizing GDP. For policy analysis, we construct five scenarios for evaluation and optimal choice. The results of the analysis show that a lower initial carbon tax rate is not necessarily better, and that a carbon tax is an effective means to reduce CO2 emissions while maintaining a certain level of GDP growth.

  15. Interleaved Carbon Minibeams: An Experimental Radiosurgery Method With Clinical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Dilmanian, F. Avraham, E-mail: dilmanian@bnl.gov [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Department of Radiation Oncology, Stony Brook University Medical Center, NY (United States); Department of Neurology, Stony Brook University Medical Center, NY (United States); Rusek, Adam [NASA Space Radiation Laboratory, Brookhaven National Laboratory, Upton, NY (United States); Fois, Giovanna R. [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Physics Department, University of Cagliari, Sardinia (Italy); Olschowka, John [Department of Neurobiology and Anatomy, University of Rochester, Rochester, NY (United States); Desnoyers, Nicolle R. [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Ross University School of Veterinary Medicine, Basseterre, St. Kitts, West Indies (Country Unknown); Park, Jane Y. [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); College of Veterinary Medicine, Cornell University, Ithaca, NY (United States); Dioszegi, Istvan [Nonproliferation and National Security Department, Brookhaven National Laboratory, Upton, NY (United States); Dane, Bari; Wang Ruiliang [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Tomasi, Dardo [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); National Institute on Alcoholism and Alcohol Abuse, Bethesda, MD (United States); Lee, Hedok [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Hurley, Sean D. [Department of Neurobiology and Anatomy, University of Rochester, Rochester, NY (United States); Coyle, Patricia K. [Department of Neurology, Stony Brook University Medical Center, NY (United States); Meek, Allen G. [Department of Radiation Oncology, Stony Brook University Medical Center, NY (United States); O' Banion, M. Kerry [Department of Neurobiology and Anatomy, University of Rochester, Rochester, NY (United States)

    2012-10-01

    Purpose: To evaluate the efficacy of 'interleaved carbon minibeams' for ablating a 6.5-mm target in a rabbit brain with little damage to the surrounding brain. The method is based on the well-established tissue-sparing effect of arrays of thin planes of radiation. Methods and Materials: Broad carbon beams from the National Aeronautics and Space Agency Space Radiation Facility at Brookhaven National Laboratory were segmented into arrays of parallel, horizontal, 0.3-mm-thick planar beams (minibeams). The minibeams' gradual broadening in tissues resulted in 0.525-mm beam thickness at the target's proximal side in the spread-out Bragg peak. Interleaving was therefore implemented by choosing a 1.05 mm beam spacing on-center. The anesthetized rabbit, positioned vertically on a stage capable of rotating about a vertical axis, was exposed to arrays from four 90 Degree-Sign angles, with the stage moving up by 0.525 mm in between. This produced a solid radiation field at the target while exposing the nontargeted tissues to single minibeam arrays. The target 'physical' absorbed dose was 40.2 Gy. Results: The rabbit behaved normally during the 6-month observation period. Contrast magnetic resonance imaging and hematoxylin and eosin histology at 6 months showed substantial focal target damage with little damage to the surrounding brain. Conclusion: We plan to evaluate the method's therapeutic efficacy by comparing it with broad-beam carbon therapy in animal models. The method's merits would combine those of carbon therapy (i.e., tight target dose because of the carbon's Bragg-peak, sharp dose falloff, and high relative biological effectiveness at the target), together with the method's low impact on the nontargeted tissues. The method's smaller impact on the nontargeted brain might allow carbon therapy at higher target doses and/or lower normal tissue impact, thus leading to a more effective treatment of radioresistant

  16. Removal and recovery of gas-phase element mercury by metal oxide-loaded activated carbon

    International Nuclear Information System (INIS)

    Mei Zhijian; Shen Zhemin; Zhao Qingjie; Wang Wenhua; Zhang Yejian

    2008-01-01

    The reusability of Co 3 O 4 (AC-Co), MnO 2 (AC-Mn) and CuCoO 4 (AC-CC) loaded activated carbon (AC) and their element mercury removal efficiency had been studied using a laboratory-scale fixed-bed reactor under simulated flue gas conditions. Tests showed that spent AC-Co could be regenerated through heating at 673 K under N 2 atmosphere and the enrichment regenerated Hg 0 could be collected to eliminate the secondary pollution. Regenerated AC-Mn and AC-CC's Hg 0 removal efficiency decreased greatly due to AC's decomposition and MnO 2 's crystal structure variation. Compared with AC and metal oxides, metal oxide-loaded AC had higher Hg 0 capture ability and capacity due to AC huge surface areas and lots of function groups. TGA analysis results showed that AC-Co and AC-Mn's HgO adsorptive capacity at 523 K reached 19.8 mg g -1 and 5.21 mg g -1 , respectively. High loading values and adsorption temperatures were beneficial to AC-Co's Hg 0 removal efficiency. However, CuCoO 4 and MnO 2 's AC decomposition ability had negative effect on AC-CC and AC-Mn's performance, respectively, especially at high adsorption temperatures and loading values. SO 2 tests showed that AC-CC had higher anti SO 2 -poisoning ability than AC-Co and AC-Mn

  17. Determinants and Characteristics of Korean Companies’ Carbon Management under the Carbon Pricing Scheme

    Directory of Open Access Journals (Sweden)

    Sunhee Suk

    2018-04-01

    Full Text Available In response to the domestic emission trading scheme, Korean companies are required to shift their strategies from voluntary or regulation-driven management approaches to innovative carbon management utilizing their carbon option linked with economic value. Using a questionnaire survey targeting companies subjected to the emission trading scheme, this study explores the status of Korean companies’ carbon management in a series of five strategies and identifies the correlation between companies’ proactive carbon strategies and pre-listed determinant factors. This study found that Korean companies’ practices in accordance with carbon pricing deviate little from conventional energy and environmental management in this phase. They are likely to be affected by the need to appear socially responsible or to make a social contribution, without having to exceed this mandate in terms activities outside of this remit. Yet, only a small proportion of companies have advanced to the stage of proactive carbon management. For them, top managers’ support and understanding are essential factors together with government pressure to factor-in issues related to carbon with their business strategies. This study provides implications for policy and corporate in promoting carbon-oriented management under the carbon policy.

  18. Investigation of HF-plasma-treated soft x-ray optical elements

    Science.gov (United States)

    Eggenstein, F.; Krivenkov, M.; Rudolph, I.; Sertsu, M. G.; Sokolov, A.; Varykhalov, A.; Wolf, J.; Zeschke, T.; Schäfers, F.

    2017-09-01

    The contamination of optical elements (mirrors and gratings) with carbon still is an issue when using soft x-ray synchrotron radiation. With an in-house developed HF-plasma treatment we are able to decontaminate our optics in-situ from carbon very efficiently. The cleaning device, a simple Al-antenna, is mounted in situ inside the mirror- and grating vacuum chambers. A systematic study of the HF-plasma cleaning efficiency was performed acquired with in-situ and exsitu methods for monitoring: An atomic force microscope (AFM) and a scanning tunneling microscope (STM) were used before and after the cleaning process to determine the surface morphology and roughness. Reflectivity angular scans using the reflectometer at the BESSY-II Metrology Station [1-3] allowed to estimate the thickness of the remaining Clayer after different cleaning steps and thereby helped us to determine the etching rate. Reflection spectra measurements in the range of 200 eV - 900 eV show the complete removal of Carbon from the optics without contaminating it with any other elements due to the plasma treatment. The data show that the plasma process improves the reflectivity and reduces the roughness of the surface. In addition to that, the region of the optical surface where the carbon has been removed becomes passivated.

  19. Carbon dioxide utilization via carbonate-promoted C-H carboxylation.

    Science.gov (United States)

    Banerjee, Aanindeeta; Dick, Graham R; Yoshino, Tatsuhiko; Kanan, Matthew W

    2016-03-10

    Using carbon dioxide (CO2) as a feedstock for commodity synthesis is an attractive means of reducing greenhouse gas emissions and a possible stepping-stone towards renewable synthetic fuels. A major impediment to synthesizing compounds from CO2 is the difficulty of forming carbon-carbon (C-C) bonds efficiently: although CO2 reacts readily with carbon-centred nucleophiles, generating these intermediates requires high-energy reagents (such as highly reducing metals or strong organic bases), carbon-heteroatom bonds or relatively acidic carbon-hydrogen (C-H) bonds. These requirements negate the environmental benefit of using CO2 as a substrate and limit the chemistry to low-volume targets. Here we show that intermediate-temperature (200 to 350 degrees Celsius) molten salts containing caesium or potassium cations enable carbonate ions (CO3(2-)) to deprotonate very weakly acidic C-H bonds (pKa > 40), generating carbon-centred nucleophiles that react with CO2 to form carboxylates. To illustrate a potential application, we use C-H carboxylation followed by protonation to convert 2-furoic acid into furan-2,5-dicarboxylic acid (FDCA)--a highly desirable bio-based feedstock with numerous applications, including the synthesis of polyethylene furandicarboxylate (PEF), which is a potential large-scale substitute for petroleum-derived polyethylene terephthalate (PET). Since 2-furoic acid can readily be made from lignocellulose, CO3(2-)-promoted C-H carboxylation thus reveals a way to transform inedible biomass and CO2 into a valuable feedstock chemical. Our results provide a new strategy for using CO2 in the synthesis of multi-carbon compounds.

  20. Carbon Management In the Post-Cap-and-Trade Carbon Economy

    Science.gov (United States)

    DeGroff, F. A.

    2013-12-01

    This abstract outlines an economic model that integrates carbon externalities seamlessly into the national and international economies. The model incorporates a broad carbon metric used to value all carbon in the biosphere, as well as all transnational commerce. The model minimizes the cost associated with carbon management, and allows for the variation in carbon avidity between jurisdictions. When implemented over time, the model reduces the deadweight loss while minimizing social cost, thus maximizing the marginal social benefit commonly associated with Pigouvian taxes. Once implemented, the model provides a comprehensive economic construct for governments, industry and consumers to efficiently weigh the cost of carbon, and effectively participate in helping to reduce their direct and indirect use of carbon, while allowing individual jurisdictions to decide their own carbon value, without the need for explicit, express agreement of all countries. The model uses no credits, requires no caps, and matches climate changing behavior to costs. The steps to implement the model for a particular jurisdiction are: 1) Define the Carbon Metric to value changes in Carbon Quality. 2) Apply the Carbon Metric to assess the Carbon Toll a) for all changes in Carbon Quality and b) for imports and exports. This economic model has 3 clear advantages. 1) The carbon pricing and cost scheme use existing and generally accepted accounting methodologies to ensure the veracity and verifiability of carbon management efforts with minimal effort and expense using standard auditing protocols. Implementing this economic model will not require any special training, tools, or systems for any entity to achieve their minimum carbon target goals within their jurisdictional framework. 2) Given the spectrum of carbon affinities worldwide, the model recognizes and provides for flexible carbon pricing regimes, but does not penalize domestic carbon-consuming producers subject to imports from exporters in

  1. Irradiation-induced structure and property changes in tokamak plasma-facing, carbon-carbon composites

    International Nuclear Information System (INIS)

    Burchell, T.D.

    1994-01-01

    Carbon-carbon composites are an attractive choice for fusion reactor plasma-facing components because of their low atomic number, superior thermal shock resistance, and low neutron activation. Next generation plasma fusion reactors, such as the International Thermonuclear Experimental Reactor (ITER), will require advanced carbon-carbon composite materials possessing high thermal conductivity to manage the anticipated severe heat loads. Moreover, ignition machines such as ITER will produce large neutron fluxes. Consequently, the influence of neutron damage on the structure and properties of carbon-carbon composite materials must be evaluated. Data from two irradiation experiments are reported and discussed here. Carbon-carbon composite materials were irradiated in target capsules in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). A peak damage dose of 4.7 displacements per atom (dpa) at 600 degree C was attained. The carbon materials irradiated included uni-directional, two-directional, and three-directional carbon-carbon composites. Dimensional changes are reported for the composite materials and are related to single crystal dimensional changes through fiber and composite structural models. Moreover, the irradiation-induced dimensional changes are reported and discussed in terms of their architecture, fiber type, and graphitization temperature. The effect of neutron irradiation on thermal conductivity of two three-directional, carbon-carbon composites is reported and the recovery of thermal conductivity due to thermal annealing is discussed

  2. Targeting BRCAness in Gastric Cancer

    Science.gov (United States)

    2017-10-01

    Award Number: W81XWH-16-1-0470 TITLE: Targeting BRCAness in Gastric Cancer PRINCIPAL INVESTIGATOR: Yelena Janjigian CONTRACTING ORGANIZATION...Sloan-Kettering Institute for Cancer Research New York, NY 10065 REPORT DATE: October 2017 TYPE OF REPORT: Annual PREPARED FOR: U.S. Army Medical...Targeting BRCAness in Gastric Cancer 5b. GRANT NUMBER W81XWH-16-1-0473 (Ashworth) 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Eric Collisson, David

  3. Targeting BRCAness in Gastric Cancer

    Science.gov (United States)

    2017-10-01

    Award Number: W81XWH-16-1-0472 TITLE: Targeting BRCAness in Gastric Cancer PRINCIPAL INVESTIGATOR: Lawrence Fong CONTRACTING ORGANIZATION...Targeting BRCAness in Gastric Cancer 5b. GRANT NUMBER W81XWH-16-1-0473 (Ashworth) 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Eric Collisson, David Quigley...for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT We performed the screen of gastric cancer cell lines for their

  4. Carbon stewardship: land management decisions and the potential for carbon sequestration in Colorado, USA

    International Nuclear Information System (INIS)

    Failey, Elisabeth L; Dilling, Lisa

    2010-01-01

    Land use and its role in reducing greenhouse gases is a key element of policy negotiations to address climate change. Calculations of the potential for enhanced terrestrial sequestration have largely focused on the technical characteristics of carbon stocks, such as vegetation type and management regime, and to some degree, on economic incentives. However, the actual potential for carbon sequestration critically depends on who owns the land and additional land management decision drivers. US land ownership patterns are complex, and consequently land use decision making is driven by a variety of economic, social and policy incentives. These patterns and incentives make up the 'carbon stewardship landscape'-that is, the decision making context for carbon sequestration. We examine the carbon stewardship landscape in the US state of Colorado across several public and private ownership categories. Achieving the full potential for land use management to help mitigate carbon emissions requires not only technical feasibility and financial incentives, but also effective implementing mechanisms within a suite of often conflicting and hard to quantify factors such as multiple-use mandates, historical precedents, and non-monetary decision drivers.

  5. Beam generation and planar imaging at energies below 2.40 MeV with carbon and aluminum linear accelerator targets.

    Science.gov (United States)

    Parsons, David; Robar, James L

    2012-07-01

    Recent work has demonstrated improvement of image quality with low-Z linear accelerator targets and energies as low as 3.5 MV. In this paper, the authors lower the incident electron beam energy between 1.90 and 2.35 MeV and assess the improvement of megavoltage planar image quality with the use of carbon and aluminum linear accelerator targets. The bending magnet shunt current was adjusted in a Varian linear accelerator to allow selection of mean electron energy between 1.90 and 2.35 MeV. Linac set points were altered to increase beam current to allow experimental imaging in a practical time frame. Electron energy was determined through comparison of measured and Monte Carlo modeled depth dose curves. Planar image CNR and spatial resolution measurements were performed to quantify the improvement of image quality. Magnitudes of improvement are explained with reference to Monte Carlo generated energy spectra. After modifications to the linac, beam current was increased by a factor greater than four and incident electron energy was determined to have an adjustable range from 1.90 MeV to 2.35 MeV. CNR of cortical bone was increased by a factor ranging from 6.2 to 7.4 and 3.7 to 4.3 for thin and thick phantoms, respectively, compared to a 6 MV therapeutic beam for both aluminum and carbon targets. Spatial resolution was degraded slightly, with a relative change of 3% and 10% at 0.20 lp∕mm and 0.40 lp∕mm, respectively, when reducing energy from 2.35 to 1.90 MV. The percentage of diagnostic x-rays for the beams examined here, ranges from 46% to 54%. It is possible to produce a large fraction of diagnostic energy x-rays by lowering the beam energy below 2.35 MV. By lowering the beam energy to 1.90 MV or 2.35 MV, CNR improves by factors ranging from 3.7 to 7.4 compared to a 6 MV therapy beam, with only a slight degradation of spatial resolution when lowering the energy from 2.35 MV to 1.90 MV.

  6. Elements of a new climate agreement by 2015

    Energy Technology Data Exchange (ETDEWEB)

    Holm Olsen, K.; Fenhann, J.; Luetken, S.

    2013-06-15

    This year's Perspectives from UNEP and UNEP Risoe Centre in collaboration with the Global Green Growth Institute (GGGI) focuses on the elements of a new climate agreement by 2015 that will contribute to achieve the 2 deg. C limit for global warming. The first paper in this publication frames the global mitigation challenge based on the UNEP Emissions Gap Report 2012. The five other articles address key elements of a new climate agreement; emissions from international aviation, a vision for carbon markets up to 2020 and beyond, how green growth strategies can address the emissions gap, redesign of a REDD+ mechanism in response to the crisis of global deforestation and how NAMAs in Southern Africa can reconcile the gap between local and global objectives for development and climate change mitigation. The Perspectives series seeks to inspire policy- and decision makers by communicating the diverse insights and visions of leading actors in the arena of low carbon development in developing countries. (Author)

  7. Magnetic susceptibility of molecular carbon: nanotubes and fullerite

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A P; Haddon, R C; Zhou, O; Fleming, R M; Zhang, J; McClure, S M; Smalley, R E [AT T Bell Laboratories, Murray Hill, NJ (United States)

    1994-07-01

    Elemental carbon can be synthesized in a variety of geometrical forms, from three-dimensional extended structures (diamond) to finite molecules (C[sub 60] fullerite). Results are presented here on the magnetic susceptibility of the least well-understood members of this family, nanotubes and C[sub 60] fullerite. (1) Nanotubes represent the cylindrical form of carbon, intermediate between graphite and fullerite. They are found to have significantly larger orientation-averaged susceptibility, on a per carbon basis, than any other form of elemental carbon. This susceptibility implies an average band structure among nanotubes similar to that of graphite. (2) High-resolution magnetic susceptibility data on C[sub 60] fullerite near the molecular orientational-ordering transition at 259 K show a sharp jump corresponding to 2.5 centimeter-gram-second parts per million per mole of C[sub 60]. This jump directly demonstrates the effect of an intermolecular cooperative transition on an intramolecular electronic property, where the susceptibility jump may be ascribed to a change in the shape of the molecule due to lattice forces.